Patent Publication Number: US-2013248258-A1

Title: Leached Cutter And Method For Improving The Leaching Process

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 13/428,635, entitled “Method to Improve the Leaching Process,” filed Mar. 23, 2012, and is incorporated in its entirety herein. 
     The present application is related to U.S. patent application Ser. No. 13/401,452, entitled “Method to Improve the Performance of a Leached Cutter” and filed on Feb. 21, 2012, U.S. patent application Ser. No. 13/401,188, entitled “Use of Capacitance to Analyze Polycrystalline Diamond” and filed on Feb. 21, 2012, and U.S. patent application Ser. No. 13/401,335, entitled “Use of Capacitance and Eddy Currents to Analyze Polycrystalline Diamond” and filed on Feb. 21, 2012, which are all incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present invention is directed generally to methods of leaching components having a polycrystalline structure. More particularly, the present invention is directed to methods of leaching components having a polycrystalline structure that include one or more cycles of a leaching process and a cleaning process, where the leaching process removes at least a portion of the catalyst materials present within the polycrystalline structure and the cleaning process removes at least a portion of the by-product materials formed during the leaching process and present within the polycrystalline structure. 
     BACKGROUND 
     Polycrystalline diamond compacts (“PDC”) have been used in industrial applications, including rock drilling applications and metal machining applications. Such compacts have demonstrated advantages over some other types of cutting elements, such as better wear resistance and impact resistance. The PDC can be formed by sintering individual diamond particles together under the high pressure and high temperature (“HPHT”) conditions referred to as the “diamond stable region,” which is typically above forty kilobars and between 1,200 degrees Celsius and 2,000 degrees Celsius, in the presence of a catalyst/solvent which promotes diamond-diamond bonding. Some examples of catalyst/solvents for sintered diamond compacts are cobalt, nickel, iron, and other Group VIII metals. PDCs usually have a diamond content greater than seventy percent by volume, with about eighty percent to about ninety-eight percent being typical. An unbacked PDC can be mechanically bonded to a tool (not shown), according to one example. Alternatively, the PDC is bonded to a substrate, thereby forming a PDC cutter, which is typically insertable within, or mounted to, a downhole tool (not shown), such as a drill bit or a reamer. 
       FIG. 1  shows a side view of a PDC cutter  100  having a polycrystalline diamond (“PCD”) cutting table  110 , or compact, in accordance with the prior art. Although a PCD cutting table  110  is described in the exemplary embodiment, other types of cutting tables, including polycrystalline boron nitride (“PCBN”) compacts, are used in alternative types of cutters. Referring to  FIG. 1 , the PDC cutter  100  typically includes the PCD cutting table  110  and a substrate  150  that is coupled to the PCD cutting table  110 . The PCD cutting table  110  is about one hundred thousandths of an inch (2.5 millimeters) thick; however, the thickness is variable depending upon the application in which the PCD cutting table  110  is to be used. 
     The substrate  150  includes a top surface  152 , a bottom surface  154 , and a substrate outer wall  156  that extends from the circumference of the top surface  152  to the circumference of the bottom surface  154 . The PCD cutting table  110  includes a cutting surface  112 , an opposing surface  114 , and a PCD cutting table outer wall  116  that extends from the circumference of the cutting surface  112  to the circumference of the opposing surface  114 . The opposing surface  114  of the PCD cutting table  110  is coupled to the top surface  152  of the substrate  150 . Typically, the PCD cutting table  110  is coupled to the substrate  150  using a high pressure and high temperature (“HPHT”) press. However, other methods known to people having ordinary skill in the art can be used to couple the PCD cutting table  110  to the substrate  150 . In one embodiment, upon coupling the PCD cutting table  110  to the substrate  150 , the cutting surface  112  of the PCD cutting table  110  is substantially parallel to the substrate&#39;s bottom surface  154 . Additionally, the PDC cutter  100  has been illustrated as having a right circular cylindrical shape; however, the PDC cutter  100  is shaped into other geometric or non-geometric shapes in other exemplary embodiments. In certain exemplary embodiments, the opposing surface  114  and the top surface  152  are substantially planar; however, the opposing surface  114  and the top surface  152  is non-planar in other exemplary embodiments. Additionally, according to some exemplary embodiments, a bevel (not shown) is formed around at least a portion of the circumference of the cutting surface  112 . 
     According to one example, the PDC cutter  100  is formed by independently forming the PCD cutting table  110  and the substrate  150 , and thereafter bonding the PCD cutting table  110  to the substrate  150 . Alternatively, the substrate  150  is initially formed and the PCD cutting table  110  is subsequently formed on the top surface  152  of the substrate  150  by placing polycrystalline diamond powder onto the top surface  152  and subjecting the polycrystalline diamond powder and the substrate  150  to a high temperature and high pressure process. Alternatively, the substrate  150  and the PCD cutting table  110  are formed and bonded together at about the same time. Although a few methods of forming the PDC cutter  100  have been briefly mentioned, other methods known to people having ordinary skill in the art can be used. 
     According to one example for forming the PDC cutter  100 , the PCD cutting table  110  is formed and bonded to the substrate  150  by subjecting a layer of diamond powder and a mixture of tungsten carbide and cobalt powders to HPHT conditions. The cobalt is typically mixed with tungsten carbide and positioned where the substrate  150  is to be formed. The diamond powder is placed on top of the cobalt and tungsten carbide mixture and positioned where the PCD cutting table  110  is to be formed. The entire powder mixture is then subjected to HPHT conditions so that the cobalt melts and facilitates the cementing, or binding, of the tungsten carbide to form the substrate  150 . The melted cobalt also diffuses, or infiltrates, into the diamond powder and acts as a catalyst for synthesizing diamond bonds and forming the PCD cutting table  110 . Thus, the cobalt acts as both a binder for cementing the tungsten carbide and as a catalyst/solvent for sintering the diamond powder to form diamond-diamond bonds. The cobalt also facilitates in forming strong bonds between the PCD cutting table  110  and the cemented tungsten carbide substrate  150 . 
     Cobalt has been a preferred constituent of the PDC manufacturing process. Traditional PDC manufacturing processes use cobalt as the binder material for forming the substrate  150  and also as the catalyst material for diamond synthesis because of the large body of knowledge related to using cobalt in these processes. The synergy between the large bodies of knowledge and the needs of the process have led to using cobalt as both the binder material and the catalyst material. However, as is known in the art, alternative metals, such as iron, nickel, chromium, manganese, and tantalum, and other suitable materials, can be used as a catalyst for diamond synthesis. When using these alternative materials as a catalyst for diamond synthesis to form the PCD cutting table  110 , cobalt, or some other material such as nickel chrome or iron, is typically used as the binder material for cementing the tungsten carbide to form the substrate  150 . Although some materials, such as tungsten carbide and cobalt, have been provided as examples, other materials known to people having ordinary skill in the art can be used to form the substrate  150 , the PCD cutting table  110 , and form bonds between the substrate  150  and the PCD cutting table  110 . 
       FIG. 2  is a schematic microstructural view of the PCD cutting table  110  of  FIG. 1  in accordance with the prior art. Referring to  FIGS. 1 and 2 , the PCD cutting table  110  has diamond particles  210  bonded to other diamond particles  210 , one or more interstitial spaces  212  formed between the diamond particles  210 , and cobalt  214  deposited within the interstitial spaces  212 . During the sintering process, the interstitial spaces  212 , or voids, are formed between the carbon-carbon bonds and are located between the diamond particles  210 . The diffusion of cobalt  214  into the diamond powder results in cobalt  214  being deposited within these interstitial spaces  212  that are formed within the PCD cutting table  110  during the sintering process. 
     Once the PCD cutting table  110  is formed and placed into operation, the PCD cutting table  110  is known to wear quickly when the temperature reaches a critical temperature. This critical temperature is about 750 degrees Celsius and is reached when the PCD cutting table  110  is cutting rock formations or other known materials. The high rate of wear is believed to be caused by the differences in the thermal expansion rate between the diamond particles  210  and the cobalt  214  and also by the chemical reaction, or graphitization, that occurs between cobalt  214  and the diamond particles  210 . The coefficient of thermal expansion for the diamond particles  210  is about 1.0×10 −6  millimeters −1 ×Kelvin −1  (“mm −1 K −1 ”), while the coefficient of thermal expansion for the cobalt  214  is about 13.0×10 −6  mm −1  K −1 . Thus, the cobalt  214  expands much faster than the diamond particles  210  at temperatures above this critical temperature, thereby making the bonds between the diamond particles  210  unstable. The PCD cutting table  110  becomes thermally degraded at temperatures above about 750 degrees Celsius and its cutting efficiency deteriorates significantly. 
     Efforts have been made to slow the wear of the PCD cutting table  110  at these high temperatures. These efforts include performing conventional acid leaching processes of the PCD cutting table  110  which removes some of the cobalt  214 , or catalyst material, from the interstitial spaces  212 . Conventional leaching processes involve the presence of an acid solution (not shown) which reacts with the cobalt  214 , or other binder/catalyst material, that is deposited within the interstitial spaces  212  of the PCD cutting table  110 . These acid solutions typically consist of highly concentrated solutions of hydrofluoric acid (HF), nitric acid (HNO 3 ), and/or sulfuric acid (H 2 SO 4 ) and are subjected to different temperature and pressure conditions. According to one example of a conventional leaching process, the PDC cutter  100  is placed within an acid solution such that at least a portion of the PCD cutting table  110  is submerged within the acid solution. The acid solution reacts with the cobalt  214 , or other binder/catalyst material, along the outer surfaces of the PCD cutting table  110 . The acid solution slowly moves inwardly within the interior of the PCD cutting table  110  and continues to react with the cobalt  214 . During the reaction, one or more by-product materials  398  ( FIG. 3 ) are formed. These by-product materials  398  ( FIG. 3 ) are usually water soluble and dissolve within the solution; however, these by-product materials  398  ( FIG. 3 ) become trapped in the interstitial spaces  21  when the concentration becomes too high and they precipitate out of solution. As more by-product material  398  ( FIG. 3 ) become trapped within the PCD cutting table  110 , the acid solution moves inwardly at even a slower rate; and hence, the rate of leaching slows down considerably within these conventional leaching processes. For this reason, a tradeoff occurs between conventional leaching process duration and the desired leaching depth, wherein costs increase as the conventional leaching process duration increases. Thus, the leaching depth is typically about 0.2 millimeters, which takes about days to achieve this depth. However, the leached depth can be more or less depending upon the PCD cutting table  110  requirements and/or the cost constraints. The removal of cobalt  214  alleviates the issues created due to the differences in the thermal expansion rate between the diamond particles  210  and the cobalt  214  and due to graphitization. Although it has been described that conventional leaching processes are used to remove at least some of the catalyst  214 , other leaching processes or catalyst removal processes can be used to remove at least some of the catalyst  214  from the interstitial spaces  212 . 
       FIG. 3  shows a cross-section view of a leached PDC cutter  300  having a PCD cutting table  310  that has been at least partially leached in accordance with the prior art. Referring to  FIG. 3 , the PDC cutter  300  includes the PCD cutting table  310  coupled to a substrate  350 . The substrate  350  is similar to substrate  150  ( FIG. 1 ) and is not described again for the sake of brevity. The substrate  350  includes a top surface  365 , a bottom surface  364 , and a substrate outer wall  366  extending from the perimeter of the top surface  365  to the perimeter of the bottom surface  364 . The PCD cutting table  310  is similar to the PCD cutting table  110  ( FIG. 1 ), but includes a leached layer  354  and an unleached layer  356 . The leached layer  354  extends from the cutting surface  312 , which is similar to the cutting surface  112  ( FIG. 1 ), towards an opposing surface  314 , which is similar to the opposing surface  114  ( FIG. 1 ). In the leached layer  354 , at least a portion of the cobalt  214  has been removed from within the interstitial spaces  212  ( FIG. 2 ) using at least one leaching process mentioned above. Thus, the leached layer  354  has been leached to a desired depth  353 . However, as previously mentioned above, one or more by-product materials  398  are formed and deposited within some of the interstitial spaces  212  ( FIG. 2 ) in the leached layer  354  during the leaching process. These by-product materials  398  are chemical by-products, or catalyst salts, of the dissolution reaction which are trapped within the open porosity of the interstitial spaces  212  ( FIG. 2 ) during and/or after the dissolution process has been completed. The unleached layer  356  is similar to the PCD cutting table  150  ( FIG. 1 ) and extends from the end of the leached layer  354  to the opposing surface  314 . In the unleached layer  356 , the cobalt  214  ( FIG. 2 ) remains within the interstitial spaces  212  ( FIG. 2 ) and has not been removed. Although a boundary line  355  is formed between the leached layer  354  and the unleached layer  356  and is depicted as being substantially linear, the boundary line  355  can be non- linear. 
     The leached PDC cutters  300  are leached to different desired depths  353  and how deep the cutter  300  has been leached has an effect on the performance of the cutter  300 . As previously mentioned, the conventional leaching process is very slow, and thus, leached PDC cutters  300  that have been leached using the conventional leaching process become more expensive as the leaching depth increases. The cost of producing the leached PDC cutters  300  can be decreased if the rate of leaching were to increase. Further, the presence of by-product materials  398  within the leached layer  354  negatively impacts the performance of the leached PDC cutter  300 . 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other features and aspects of the invention are best understood with reference to the following description of certain exemplary embodiments, when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  shows a side view of a PDC cutter having a PCD cutting table in accordance with the prior art; 
         FIG. 2  is a schematic microstructural view of the PCD cutting table of  FIG. 1  in accordance with the prior art; 
         FIG. 3  shows a cross-sectional view of a leached PDC cutter having a PCD cutting table that has been at least partially leached in accordance with the prior art; 
         FIG. 4  is a flowchart depicting a leaching method in accordance with an exemplary embodiment of the present invention; 
         FIG. 5  shows a cross-sectional view of an intermediately leached PDC cutter in accordance with an exemplary embodiment of the present invention; 
         FIG. 6  shows a cross-sectional view of the intermediately cleaned leached PDC cutter in accordance with an exemplary embodiment of the present invention; 
         FIG. 7  is a cross-sectional view of a by-products removal apparatus in accordance with an exemplary embodiment; 
         FIG. 8  is a cross-sectional view of a by-products removal apparatus in accordance with another exemplary embodiment; 
         FIG. 9  is a cross-sectional view of a by-products removal apparatus in accordance with another exemplary embodiment; 
         FIG. 10  is a cross-sectional view of a by-products removal apparatus in accordance with another exemplary embodiment; 
         FIG. 11  is a flowchart depicting a by-product materials removal verification method in accordance with an exemplary embodiment of the present invention; 
         FIG. 12  is a schematic view of a capacitance measuring system in accordance to one exemplary embodiment of the present invention; 
         FIG. 13  is a schematic view of a capacitance measuring system in accordance to another exemplary embodiment of the present invention; 
         FIG. 14  is a data scattering chart that shows the measured capacitance values for a plurality of intermediately leached and/or intermediately cleaned cutters at different cleaning cycles according to an exemplary embodiment; and 
         FIG. 15  shows a cross-sectional view of the cleaned leached PDC cutter having a PCD cutting table that has been leached to the desired leaching depth in accordance with an exemplary embodiment. 
     
    
    
     The drawings illustrate only exemplary embodiments of the invention and are therefore not to be considered limiting of its scope, as the invention may admit to other equally effective embodiments. 
     BRIEF DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The present invention is directed generally to methods of leaching components having a polycrystalline structure. More particularly, the present invention is directed to methods of leaching components having a polycrystalline structure that include one or more cycles of a leaching process and a cleaning process, where the leaching process removes at least a portion of the catalyst materials present within the polycrystalline structure and the cleaning process removes at least a portion of the by-product materials formed during the leaching process and also present within the polycrystalline structure. Each additional leaching process and cleaning process removes catalyst materials and by-product materials, respectively, from deeper within the polycrystalline structure. The cleaning process allows the next leaching process to perform at a faster rate than if the cleaning process did not happen. Although the description of exemplary embodiments is provided below in conjunction with a polycrystalline diamond compact (“PDC”) cutter, alternate embodiments of the invention may be applicable to other types of cutters or components including, but not limited to, polycrystalline boron nitride (“PCBN”) cutters or PCBN compacts. As previously mentioned, the compact is mountable to a substrate to form a cutter or is mountable directly to a tool for performing cutting processes. The invention is better understood by reading the following description of non-limiting, exemplary embodiments with reference to the attached drawings, wherein like parts of each of the figures are identified by like reference characters, and which are briefly described as follows. 
       FIG. 4  is a flowchart depicting a leaching method  400  in accordance with an exemplary embodiment of the present invention. Although  FIG. 4  shows a series of steps depicted in a certain order, the order of one or more steps can be rearranged, combined into fewer steps, and/or separated into more steps than that shown in other exemplary embodiments. Referring to  FIG. 4 , the leaching method  400  begins at step  410 . Upon starting at step  410 , the leaching method  400  proceeds to step  420 . At step  420 , one or more PDC cutters are obtained. According to certain exemplary embodiments, each PDC cutter includes a polycrystalline structure having a first end and a second end. The polycrystalline structure also includes one or more catalyst materials deposited therein. These PDC cutters have been described above in detail with respect to  FIGS. 1 and 2  and therefore are not described again for the sake of brevity. 
     The leaching method  400  proceeds to step  430 . At step  430 , a leaching process is performed on the polycrystalline structure of one or more PDC cutters. The leaching process removes at least a portion of the catalyst materials from a leached portion of the polycrystalline structure and forms one or more by-product materials. The leached portion extends from the first end to a leaching depth end, where the leaching depth end is between the first end and the second end. At least a portion of the by-product materials is deposited within the leached portion. The leaching process continues until the rate of leaching decreases below a desired leaching threshold, which is determined by a user. Alternatively, the leaching process continues for a desired leaching period, which also is determined by the user. The desired leaching period ranges from a few minutes to several hours or days, if desired. Hence, at step  430 , an intermediately leached PDC cutter  500  ( FIG. 5 ) is formed. 
       FIG. 5  shows a cross-sectional view of the intermediately leached PDC cutter  500  in accordance with an exemplary embodiment of the present invention. Referring to  FIG. 5 , the intermediately leached PDC cutter  500  includes the PCD cutting table  510 , which is a polycrystalline structure, coupled to the substrate  350 . The substrate  350  has been previously described with respect to  FIG. 3  and is not described again for the sake of brevity. The PCD cutting table  510  is similar to the PCD cutting table  310  ( FIG. 3 ), but includes a leached layer  554  and an unleached layer  556  having different depths, or thicknesses, than the leached layer  354  ( FIG. 3 ) and the unleached layer  356  ( FIG. 3 ), respectively, of the leached PDC cutter  300  ( FIG. 3 ). The leached layer  554  also is referred to herein as a leached portion  554 . Specifically, the leached portion  554  has a smaller depth, or smaller thickness, than leached layer  354  ( FIG. 3 ). Also, the unleached layer  556  has a greater depth, or greater thickness, than the unleached layer  356  ( FIG. 3 ). Hence, the depth of the leached portion  554 , or an intermediate leaching depth  553  according to some exemplary embodiments, within the intermediately leached PDC cutter  500  has not yet reached the leaching depth  353  ( FIG. 3 ), or desired leaching depth, of the leached PDC cutter  300  ( FIG. 3 ). The intermediately leached PDC cutter  500  is formed using a leaching process for a shorter time period than when forming the leached PDC cutter  300  ( FIG. 3 ). 
     The leached portion  554  extends from the cutting surface  512 , or first end, which is similar to the cutting surface  312  ( FIG. 3 ), towards an opposing surface  514 , or second end, which is similar to the opposing surface  314  ( FIG. 3 ). In the leached portion  554 , at least a portion of the cobalt  214  has been removed from within the interstitial spaces  212  ( FIG. 2 ) using at least one leaching process, which is described in further detail below. Thus, the leached portion  554  has been leached to the intermediate leaching depth  553 . However, as previously mentioned above, one or more by-product materials  398  are formed and deposited within some of the interstitial spaces  212  ( FIG. 2 ) in the leached portion  554  during the leaching process. These by-product materials  398  are chemical by-products, or catalyst salts, of the dissolution reaction which are trapped within the open porosity of the interstitial spaces  212  ( FIG. 2 ) during and/or after the dissolution process has been completed. Further, these trapped by-product materials  398  cause the leaching rate to decrease as the concentration of by-product materials  398  within the leached portion  554  increases. The unleached layer  556  is composed similarly as the PCD cutting table  150  ( FIG. 1 ) and extends from a leaching depth end  555  of the leached portion  554  to the opposing surface  514 . In the unleached layer  556 , the cobalt  214  remains within the interstitial spaces  212  ( FIG. 2 ) and has not been removed. Although the leaching depth end  555  is depicted as being substantially linear, the leaching depth end  555  can be non-linear. 
     The leaching process is performed a first time and removes at least a portion of the catalyst materials  214  from the PDC cutter  100  ( FIG. 1 ) to form the intermediately leached PDC cutter  500 . The leaching process is performed using a catalyst removal apparatus according to some exemplary embodiments. There are several catalyst removal apparatuses that are known or not yet known to people having ordinary skill in the art which are applicable to the present disclosure. For example, one such catalyst removal apparatus (not shown) includes a tank (not shown), or tray, having a cavity (not shown) formed therein and an acid solution (not shown) placed within the cavity. This apparatus is operated using the conventional leaching process described above according to some exemplary embodiments and is not repeated again for the sake of brevity. Other examples of the catalyst removal apparatus include, but are not limited to, at least those apparatuses which utilize acid leaching processes and/or electrochemical removal processes. 
     Referring back to  FIG. 4 , the leaching method  400  proceeds to step  440 . At step  440 , a cleaning process is performed on the leached portion  554  ( FIG. 5 ) of the intermediately leached PDC cutter  500  ( FIG. 5 ). The cleaning process removes at least a portion of the by-product materials  398  ( FIG. 5 ) from the leached portion  554  ( FIG. 5 ) of the polycrystalline structure  510  ( FIG. 5 ). At step  440 , an intermediately cleaned leached PDC cutter  600  ( FIG. 6 ) is formed from the intermediately leached PDC cutter  500  ( FIG. 5 ) where at least some of the by-product materials  398  ( FIG. 5 ) has been removed. 
       FIG. 6  shows a cross-sectional view of the intermediately cleaned leached PDC cutter  600  in accordance with an exemplary embodiment of the present invention. Referring to  FIG. 6 , the intermediately cleaned leached PDC cutter  600  includes the PCD cutting table  610  coupled to the substrate  350 . The substrate  350  has been previously described with respect to  FIG. 3  and is not described again for the sake of brevity. The PCD cutting table  610  is similar to the PCD cutting table  510  ( FIG. 5 ), but includes a cleaned leached portion  654  that has had at least a portion of the by-product materials  398  removed from the leached portion  554  ( FIG. 5 ). Thus, PCD cutting table  610  includes the cleaned leached portion  654  and the unleached layer  556  which is disposed between the cleaned leached portion  654  and the substrate  350 . The cleaned leached portion  654  extends from the cutting surface  512 , which has been described above with respect to  FIG. 5 , towards the opposing surface  514 , which also has been described with respect to  FIG. 5 . In the cleaned leached portion  654 , at least a portion of the cobalt  214  has been removed from within the interstitial spaces  212  ( FIG. 2 ) using at least one leaching process mentioned above when compared to the PCD cutting table  110  ( FIG. 1 ). Thus, the cleaned leached portion  654  has been leached to the intermediate leaching depth  553 . However, as previously mentioned above, one or more by-product materials  398  were formed and deposited within some of the interstitial spaces  212  ( FIG. 2 ) in the leached portion  554  ( FIG. 5 ) during the leaching process. However, at least a portion of these by-product materials  398  are removed from the leached portion  554  ( FIG. 5 ), thereby forming cleaned leached portion  654  of the intermediately cleaned leached PDC cutter  600 . The process of removing the by-product materials  398  from the leached portion  554  ( FIG. 5 ) is described in further detail below. As previously mentioned, these by-product materials  398  are chemical by-products, or catalyst salts, of the dissolution reaction which are trapped within the open porosity of the interstitial spaces  212  ( FIG. 2 ) after the dissolution process has been completed. The unleached layer  556  has been previously described with respect to  FIG. 5  and therefore is not repeated for the sake of brevity. 
     The cleaning process is performed a first time and removes the by-product materials from the leached portion  554  ( FIG. 5 ) of the intermediately leached PDC cutter  500  ( FIG. 5 ) to form the intermediately cleaned leached PDC cutter  600 . The cleaning process continues until a desired cleaning level is determined, which is determined by a user. Alternatively, the cleaning process continues for a desired cleaning period, which also is determined by the user. The desired cleaning period ranges from a few minutes to several hours or days, if desired. The cleaning process is performed using a by-products removal apparatus according to some exemplary embodiments. There are several by-products removal apparatuses that are known or not yet known to people having ordinary skill in the art which are applicable to the present disclosure. For example,  FIG. 7  is a cross-sectional view of a by-products removal apparatus  700  in accordance with an exemplary embodiment. Referring to  FIG. 7 , the by-products removal apparatus  700  includes the intermediately leached PDC cutter  500 , a covering  710 , an immersion tank  720 , a cleaning fluid  730 , a transducer  750 , and at least one power source  760 . According to certain exemplary embodiments, the covering  710  is optional. As the cleaning fluid  730  becomes increasingly more basic or more acidic, the use of the covering  710  becomes less optional. 
     The intermediately leached PDC cutter  500  has been previously described with respect to  FIG. 5  and therefore is not described again in detail. Referring to  FIGS. 5 and 7 , the intermediately leached PDC cutter  500  includes the PCD cutting table  510  and the substrate  350  that is coupled to the PCD cutting table  510 . As previously mentioned, the PCD cutting table  510  includes the leached portion  554  and the unleached layer  556  disposed between the leached portion  554  and the substrate  350 . The leached portion  554  has at least a portion of the catalyst material  214  removed from therein using a known leaching process or some other process for removing the catalyst material  214 . The leached portion  554  also includes by-product materials  398 , which has been discussed in detail above and is not repeated again for the sake of brevity. The unleached layer  556  includes catalyst material  214  which has not been removed. Although the PCD cutting table  510  is used in the exemplary embodiment, other types of cutting tables, including PCBN compacts, are used in alternative exemplary embodiments. The PCD cutting table  510  is about one hundred thousandths of an inch (2.5 millimeters) thick; however, the thickness is variable depending upon the application in which the PCD cutting table  510  is to be used. Also, although the intermediately leached PDC cutter  500  is described as being used in the by-products removal apparatus  700 , the leached PDC cutter  300  ( FIG. 3 ) can be used in certain exemplary embodiments. 
     Referring to  FIGS. 5 and 7  and as previously mentioned, the by-products removal apparatus  700  includes the covering  710 , which is optional. In certain exemplary embodiments, the covering  710  is annularly shaped and forms a channel  712  therein. The covering  710  surrounds at least a portion of a substrate outer wall  366  extending from about the perimeter of a top surface  365  of the substrate  350  towards a bottom surface  364  of the substrate  350 . The bottom surface  364 , the top surface  365 , and the substrate outer wall  366  of substrate  350  are similar to the bottom surface  154  ( FIG. 1 ), the top surface  152  ( FIG. 1 ), and the substrate outer wall  156  ( FIG. 1 ), respectively, of the substrate  150  ( FIG. 1 ) and is not repeated herein again. In some exemplary embodiments, a portion of the covering  710  also surrounds a portion of the perimeter of a PCD cutting table outer wall  576  extending from the perimeter of the opposing surface  514  towards the cutting surface  512 . The PCD cutting table outer wall  576  of the intermediately leached PDC cutter  500  is similar to the PCD cutting table outer wall  116  ( FIG. 1 ) of the PDC cutter  100  ( FIG. 1 ) and therefore is not repeated again. Thus, the cutting surface  512  and at least a portion of the PCD cutting table outer wall  576  is exposed and not concealed by the covering  710  in certain exemplary embodiments. The covering  710  is fabricated using epoxy resin; however, other suitable materials, such as a plastic, porcelain, or Teflon®, can be used without departing from the scope and spirit of the exemplary embodiment. In some exemplary embodiments, the covering  710  is positioned around at least a portion of the intermediately leached PDC cutter  500  by inserting the intermediately leached PDC cutter  500  through the channel  712  of the covering  710 . The covering  710  is friction fitted to the intermediately leached PDC cutter  500  in some exemplary embodiments, while in other exemplary embodiments, the covering  710  is securely positioned by placing an o-ring (not shown), or other suitable known device, around the intermediately leached PDC cutter  500  and inserting the intermediately leached PDC cutter  500  and the coupled o-ring into the covering  710  so that the o-ring is inserted into a circumferential groove (not shown) formed within the internal surface of the covering  710 . In an alternative exemplary embodiment, the covering  710  is circumferentially applied onto the substrate outer wall  366  and/or the PCD cutting table outer wall  576  of the intermediately leached PDC cutter  500 . Although some methods for securing the covering  710  to the intermediately leached PDC cutter  500  have been described, other methods known to people having ordinary skill in the art can be used without departing from the scope and spirit of the exemplary embodiment. The covering  710  protects the surface of the substrate outer wall  366  and/or at least a portion of the PCD cutting table outer wall  576  to which it is applied from being exposed to the cleaning fluid  730 , which is discussed in further detail below. 
     The immersion tank  720  includes a base  722  and a surrounding wall  724  extending substantially perpendicular around the perimeter of the base  722 , thereby forming a cavity  726  therein. According to certain exemplary embodiments, the base  722  is substantially planar; however, the base  722  is non-planar in other exemplary embodiments. Also in alternative exemplary embodiments, the surrounding wall  724  is non-perpendicular to the base  722 . Also, the immersion tank  720  is formed having a rectangular shape. Alternatively, the immersion tank  720  is formed having any other geometric shape or non-geometric shape. In some exemplary embodiments, the immersion tank  720  is fabricated using a plastic material; however, other suitable materials, such as metal, metal alloys, or glass, are used in other exemplary embodiments. The material used to fabricate the immersion tank  720  typically does not react with the cleaning fluid  730 . According to some exemplary embodiments, a removable lid (not shown) is used to enclose at least the intermediately leached PDC cutter  500  and the transducer  750 , thereby providing a seal to the cavity  730 . Hence, the removable lid and the immersion tank  720  together form a pressurized vessel (not shown). In these exemplary embodiments, the power source  760  can be coupled to the lid, can be positioned outside the pressurized vessel as long as the pressurized vessel provides a port (not shown) to electrically couple the power source  760  to the transducer  750 , or can be integrated with the transducer  750 . 
     The cleaning fluid  730  is placed within the cavity  726  of the immersion tank  720  and filled to a depth of at least the thickness of the PCD cutting table  710 . The cleaning fluid  730  is de-ionized water in the exemplary embodiment. The by-product materials  398  that clog the PCD open porosity is dissolvable in the cleaning fluid  730 . According to some exemplary embodiments, one or more additional chemicals are added to the de-ionized water to form the cleaning fluid  730  and increase the rate at which the by-product materials  398  are dissolved into the cleaning fluid  730 . These additional chemicals are based upon the composition of the by-product materials  398 . Some examples of these additional chemicals are acetic acid and/or formic acid to make the solution slightly acidic or ammonia to make the solution slightly basic. However, in other exemplary embodiments, any fluid or solution that is able to dissolve and/or react with the by-product materials  398  can be used for the cleaning fluid  730  in lieu of, or in addition to, the de-ionized water. According to some exemplary embodiments, the cleaning fluid  730  is heated to increase the rate at which the by-product materials  398  are dissolved into the cleaning fluid  730  and hence accelerate the cleaning process. The temperature of the cleaning fluid  730  can be heated up to 100° C. in the immersion tank  720  or some similar type tank. However, the temperature of the cleaning fluid  730  can be heated higher than 100° C. in the pressurized vessel mentioned above, thereby avoiding or reducing boiling of the cleaning fluid  730 . 
     The transducer  750  is coupled to the intermediately leached PDC cutter  500  according to some exemplary embodiments. According to some exemplary embodiments, a portion of the transducer  750  is coupled to the bottom surface  364  of the intermediately leached PDC cutter  500 ; however the transducer  750  can be coupled to a portion of the substrate outer wall  366  in other exemplary embodiments. Alternatively, the transducer  750  is coupled to a portion of the immersion tank  720  or positioned within the cleaning fluid  730 , thereby producing vibrations which propagate through the cleaning fluid  730  and into the intermediately leached PDC cutter  500 . The transducer  750  also is coupled to a power source  760  using an electrical wire  761 . The transducer  750  converts electric current supplied from the power source  760  into vibrations that are propagated through the intermediately leached PDC cutter  500 . The transducer  750  is shaped into a cylindrical shape and has a circumference sized approximately similarly to the circumference of the bottom surface  364 . However, the shape and size of the transducer  750  varies in other exemplary embodiments. The transducer  750  is a piezoelectric transducer; however, the transducer  750  is a magnetostrictive transducer in other exemplary embodiments. The transducer  750  operates at a frequency of about forty kilohertz (kHz) in some exemplary embodiments. In other exemplary embodiments, the transducer  750  operates at a frequency ranging from about twenty kHz to about fifty kHz; yet, in still other exemplary embodiments, the operating frequency is higher or lower than the provided range. The transducer  750  supplies ultrasonic vibrations  755  which propagate through the intermediately leached PDC cutter  500  and facilitate the by-product materials  398  removal from the interstitial spaces  212  ( FIG. 2 ) formed within the PCD cutting table  510 , which is further described below. 
     Once the by-products removal apparatus  700  has been set up and at least a portion of the PCD cutting table  510  is immersed into the cleaning fluid  730 , the cleaning fluid  730  penetrates into the leached portion  554  and dissolves the by-product materials  398  that are clogging the PCD open porosity. The by-product materials  398  are highly soluble in the cleaning fluid  730 . In certain exemplary embodiments, the transducer  750  and the power source  760  are included in the by-product removal apparatus  700 . The power source  760  is turned “on” to facilitate removal of the by-product materials  398  from the PCD cutting table  510  back into the cleaning fluid  730 . The transducer  750  produces ultrasonic vibrations  755  into the intermediately leached PDC cutter  500  which promotes the removal of the by-product materials  398  from the PCD cutting table  510  back into the cleaning fluid  730 . The operating frequency of the transducer  750  and the intensity of the elastic waves emitted from the transducer  750  can be adjusted to maximize the amount of vibrations  755  delivered to the PCD cutting table  510 . Furthermore, the ultrasonic vibrations  755  mechanically improve the cleaning fluid  730  circulation rate into and out of the interstitial spaces  212  ( FIG. 2 ), thereby providing fresh cleaning fluid  730  into the interstitial spaces  212  ( FIG. 2 ). Once the by-product material  398  is removed from the PCD cutting table  510 , the cleaning fluid  730  is able to proceed deeper into the PCD cutting table  510  and dissolve more by-product materials  398  located within additional interstitial voids  212  ( FIG. 2 ). Upon at least some of the by-product materials  398  being removed from the leached portion  554 , the intermediately leached PDC cutter  500  becomes the intermediately cleaned leached PDC cutter  600  ( FIG. 6 ). Although a single intermediately leached PDC cutter  500  is shown to be immersed in the cleaning fluid  730 , several intermediately leached PDC cutters  500  can be immersed into the cleaning fluid  730  to remove the by-product materials  398  from each of the PCD cutting tables  510  simultaneously in other exemplary embodiments. 
     In another example,  FIG. 8  is a cross-sectional view of a by-products removal apparatus  800  in accordance with another exemplary embodiment. The by-products removal apparatus  800  is similar to the by-products removal apparatus  700  ( FIG. 7 ) except that the transducer  750  of the by-products removal apparatus  800  is submerged within the cleaning fluid  730 . The transducer  750  transmits ultrasonic vibrations  755  into the cleaning fluid  730 , which then transmits the vibrations  755  into the PCD cutting table  510 . As previously mentioned, the ultrasonic vibrations  755  facilitate removal of the by-product materials  398 , or salt, within the interstitial void  212  ( FIG. 2 ) and increase the recirculation rate of the fresh cleaning fluid  730  into the PCD cutting table  510 . Thus, the by-product material  398  removal rate is substantially increased using the transducer  750 . Alternatively, the transducer  750  is coupled to a portion of the immersion tank  720 . The other exemplary embodiments and/or modifications as described with respect to  FIG. 7  above are applicable to the present exemplary embodiment. 
     In another example,  FIG. 9  is a cross-sectional view of a by-products removal apparatus  900  in accordance with another exemplary embodiment. The by-products removal apparatus  900  is similar to the by-products removal apparatus  700  ( FIG. 7 ) except that the cavity  726  of the immersion tank  720  is covered by a lid  990  in the by-products removal apparatus  900 . In certain exemplary embodiments, the lid  990  provides a seal to the cavity  726 , thereby allowing the cavity  726  to be pressurized and the cleaning fluid  730  to be heated at higher temperatures, such as above 100° C. These higher temperatures increase the cleaning rate of the by-products materials  398  ( FIG. 5 ). A gasket (not shown) positioned between the lid  990  and the immersion tank  720  can be used to facilitate providing the seal. The sealed lid  990  and the immersion tank  720  collectively form the pressurizable vessel  910 . In the exemplary embodiments that use the lid  990 , the power source  760  can be coupled to the lid  990  via a clamp  930 , can be positioned outside the pressurizable vessel  910  as long as the pressurized vessel  910  provides a port (not shown) to electrically couple the power source  760  to the transducer  750 , or can be integrated with the transducer  750 . The other exemplary embodiments and/or modifications as described with respect to  FIG. 7  above are applicable to the present exemplary embodiment. 
     In yet another example,  FIG. 10  is a cross-sectional view of a by-products removal apparatus  1000  in accordance with another exemplary embodiment. The by-products removal apparatus  1000  is similar to the by-products removal apparatus  800  ( FIG. 8 ) except that the cavity  726  of the immersion tank  720  is covered by a lid  990  in the by-products removal apparatus  1000 . In certain exemplary embodiments, the lid  990  provides a seal to the cavity  726 , thereby allowing the cavity  726  to be pressurized and the cleaning fluid  730  to be heated at higher temperatures, such as above 100° C. These higher temperatures increase the cleaning rate of the by-products materials  398  ( FIG. 5 ). A gasket (not shown) positioned between the lid  990  and the immersion tank  720  can be used to facilitate providing the seal. The sealed lid  990  and the immersion tank  720  collectively form the pressurizable vessel  910 . In the exemplary embodiments that use the lid  990 , the power source  760  can be coupled to the lid  990  via a clamp  930 , can be positioned outside the pressurizable vessel  910  as long as the pressurized vessel  910  provides a port (not shown) to electrically couple the power source  760  to the transducer  750 , or can be integrated with the transducer  750 . The other exemplary embodiments and/or modifications as described with respect to  FIG. 7  and above are applicable to the present exemplary embodiment. 
     According to some exemplary embodiments, the effectiveness of the by-product materials removal process is optionally verified. In the event that the intermediately cleaned leached PDC cutter  600  is not cleaned to a desired level, the intermediately cleaned leached PDC cutter  600  is further cleaned in either the same cleaning fluid  730  or a fresh cleaning fluid  730  until the desired level is reached. Thus, multiple cleaning cycles are performed on the intermediately leached PDC cutter  500  in some exemplary embodiments to fully, or substantially, remove the by-product materials  398 .  FIG. 11  is a flowchart depicting a by-product materials removal verification method  1100  in accordance with an exemplary embodiment of the present invention. Although  FIG. 11  shows a series of steps depicted in a certain order, the order of one or more steps can be rearranged, combined into fewer steps, and/or separated into more steps than that shown in other exemplary embodiments. Referring to  FIG. 11 , the by-product materials removal verification method  1100  begins at step  1110 . Upon starting at step  1110 , the by-product materials removal verification method  1100  proceeds to step  1120 . At step  1120 , one or more intermediately leached PDC cutters are obtained. According to certain exemplary embodiments, each intermediately leached PDC cutter includes a polycrystalline structure having a leached portion and an unleached layer. The leached portion includes one or more by-product materials. These intermediately leached PDC cutters have been described above in detail with respect to  FIG. 5  and therefore are not described again for the sake of brevity. 
     The by-product materials removal verification method  1100  proceeds to step  1130 . At step  1130 , at least a portion of the by-product materials from the intermediately leached PDC cutter is removed thereby forming an intermediately cleaned leached PDC cutter. The by-product materials are removed from the intermediately leached PDC cutter using the by-products removal apparatus  700  ( FIG. 7 ), the by-products removal apparatus  800  ( FIG. 8 ), the by-products removal apparatus  900  ( FIG. 9 ), the by-products removal apparatus  1000  ( FIG. 10 ), or some other by-products removal apparatus that becomes known to other people having ordinary skill in the art with the benefit of the present disclosure. As previously described, a cleaning fluid and a transducer, according to some exemplary embodiments, are used to remove at least a portion of the by-product materials from the intermediately leached PDC cutter. 
     The by-product materials removal verification method  1100  proceeds to step  1140 . At step  1140 , at least one capacitance value for each of the intermediately cleaned leached PDC cutter is measured. The intermediately cleaned leached PDC cutter has been described above in detail with respect to  FIG. 6  and therefore is not described again for the sake of brevity. The capacitance value is determined using a capacitance measuring system, as described below. 
       FIG. 12  is a schematic view of a capacitance measuring system  1200  in accordance to one exemplary embodiment of the present invention. Referring to  FIG. 12 , the capacitance measuring system  1200  includes a capacitance measuring device  1210 , the intermediately cleaned leached PDC cutter  600 , a first wire  1230 , and a second wire  1240 . In other exemplary embodiments, the intermediately leached PDC cutter  500  ( FIG. 5 ) is used in lieu of the intermediately cleaned leached PDC cutter  600 . Although certain components have been enumerated as being included in the capacitance measuring system  1200 , additional components are included in other exemplary embodiments. Additionally, although the description provided below has been provided with respect to the intermediately cleaned leached PDC cutter  600 , a different component, such as the PCD cutting table  610  alone or other component that includes another type of intermediately clean leached polycrystalline structure or intermediately leached polycrystalline structure, is used in lieu of the intermediately cleaned leached PDC cutter  600 . The cleaned leached PDC cutter  600  has been previously described with respect to  FIG. 6  and is not repeated again herein for the sake of brevity. 
     The capacitance measuring device  1210  is a device that measures the capacitance of an energy storage device, which is the intermediately cleaned leached PDC cutter  600 , or the intermediately leached PDC cutter  500  ( FIG. 5 ), in the instant exemplary embodiment. Capacitance is a measure of the amount of electric potential energy stored, or separated, for a given electric potential. A common form of energy storage device is a parallel-plate capacitor. In the instant exemplary embodiment, the intermediately cleaned leached PDC cutter  600  is an example of the parallel-plate capacitor. The capacitance of the energy storage device is typically measured in farads, or nanofarads. 
     One example of the capacitance measuring device  1210  is a multi-meter; however, other capacitance measuring devices known to people having ordinary skill in the art are used in one or more alternative exemplary embodiments. The multi-meter  1210  includes a positionable dial  1212 , a plurality of measurement settings  1214 , a display  1216 , a positive terminal  1218 , and a negative terminal  1219 . According to some exemplary embodiments, the positionable dial  1212  is rotatable in a clockwise and/or counter-clockwise manner and is set to one of several available measurement settings  1214 . In the instant exemplary embodiment, the positionable dial  1212  is set to a nanofaraday setting  1215  so that the multi-meter  1210  measures capacitance values. The display  1216  is fabricated using polycarbonate, glass, plastic, or other known suitable material and communicates a measurement value, such as a capacitance value, to a user (not shown) of the multi-meter  1210 . The positive terminal  1218  is electrically coupled to one end of the first wire  1230 , while the negative terminal  1219  is electrically coupled to one end of the second wire  1240 . 
     The first wire  1230  is fabricated using a copper wire or some other suitable conducting material or alloy known to people having ordinary skill in the art. According to some exemplary embodiments, the first wire  1230  also includes a non-conducting sheath (not shown) that surrounds the copper wire and extends from about one end of the copper wire to an opposing end of the cooper wire. The two ends of the copper wire are exposed and are not surrounded by the non-conducting sheath. In some exemplary embodiments, an insulating material (not shown) also surrounds the copper wire and is disposed between the copper wire and the non-conducting sheath. The insulating material extends from about one end of the non-conducting sheath to about an opposing end of the non-conducting sheath. As previously mentioned, one end of the first wire  830  is electrically coupled to the positive terminal  1218 , while the opposing end of the first wire  1230  is electrically coupled to the cutting surface  512  of the intermediately cleaned leached PDC cutter  600 . The opposing end of the first wire  1230  is electrically coupled to the cutting surface  512  in one of several methods. In one example, the first wire  1230  is electrically coupled to the cutting surface  512  using one or more fastening devices (not shown), such as a clamp, or using an equipment (not shown) that supplies a force to retain the first wire  1230  in electrical contact with the cutting surface  512 . In another example, a clamp (not shown) is coupled to the opposing end of the first wire  1230  and a conducting component (not shown), such as aluminum foil, is coupled to, or placed in contact with, the cutting surface  512 . The clamp is electrically coupled to the conducting component, thereby electrically coupling the first wire  1230  to the cutting surface  512 . Additional methods for coupling the first wire  1230  to the cutting surface  512  can be used in other exemplary embodiments. 
     The second wire  1240  is fabricated using a copper wire or some other suitable conducting material or alloy known to people having ordinary skill in the art. According to some exemplary embodiments, the second wire  1240  also includes a non-conducting sheath (not shown) that surrounds the copper wire and extends from about one end of the copper wire to an opposing end of the cooper wire. The two ends of the copper wire are exposed and are not surrounded by the non-conducting sheath. In some exemplary embodiments, an insulating material (not shown) also surrounds the copper wire and is disposed between the copper wire and the non-conducting sheath. The insulating material extends from about one end of the non-conducting sheath to an opposing end of the non-conducting sheath. As previously mentioned, one end of the second wire  1240  is electrically coupled to the negative terminal  1219 , while the opposing end of the second wire  1240  is electrically coupled to a bottom surface  364 , which is similar to the bottom surface  154  ( FIG. 1 ), of the intermediately cleaned leached PDC cutter  600 . The second wire  1240  is electrically coupled to the bottom surface  364  in a similar manner as the first wire  1230  is electrically coupled to the cutting surface  512 . 
     Hence, a circuit  1205  is completed using the multi-meter  1210 , the first wire  1230 , the intermediately cleaned leached PDC cutter  600 , and the second wire  1240 . The current is able to flow from the positive terminal  1218  of the multi-meter  1210  to the cutting surface  512  of the intermediately cleaned leached PDC cutter  600  through the first wire  1230 . The current then flows through the intermediately cleaned leached PDC cutter  600  to the bottom surface  364  of the intermediately cleaned leached PDC cutter  600 . When the multi-meter  1210  is turned on, a voltage differential exists between the cutting surface  512  and the bottom surface  364 . The current then flows from the bottom surface  364  to the negative terminal  1219  of the multi-meter  1210  through the second wire  1240 . The capacitance measurement of the intermediately cleaned leached PDC cutter  600  is determined when the value displayed on the display  1216  reaches a peak value or remains constant for a period of time. The use, analyzing of the results, and other information regarding the capacitance measuring system  1200  is described in U.S. patent application Ser. No. 13/401,188, entitled “Use of Capacitance to Analyze Polycrystalline Diamond” and filed on Feb. 21, 2012, which has been incorporated by reference herein. 
       FIG. 13  is a schematic view of a capacitance measuring system  1300  in accordance to another exemplary embodiment of the present invention. Referring to  FIG. 13 , the capacitance measuring system  1300  includes the capacitance measuring device  1210 , the intermediately cleaned leached PDC cutter  600 , the first wire  1230 , the second wire  1240 , a first conducting material  1310 , a second conducting material  1320 , a first insulating material  1330 , a second insulating material  1340 , and an Arbor Press  1350 . In certain alternative exemplary embodiments, the intermediately leached PDC cutter  500  ( FIG. 5 ) is used in lieu of the intermediately cleaned leached PDC cutter  600 . Although certain components have been enumerated as being included in the capacitance measuring system  1300 , additional components are included in other exemplary embodiments. Further, although certain components have been enumerated as being included in the capacitance measuring system  1300 , alternative components having similar functions as the enumerated components are used in alternative exemplary embodiments. Additionally, although the description provided below has been provided with respect to the intermediately cleaned leached PDC cutter  600 , a different component, such as the PCD cutting table  610  ( FIG. 6 ) alone or other component that includes another type of leached, or cleaned leached, polycrystalline structure, is used in lieu of the intermediately cleaned leached PDC cutter  600 . The capacitance measuring device  1210 , the intermediately cleaned leached PDC cutter  600 , the first wire  1230 , and the second wire  1240  have been previously described and are not repeated again herein for the sake of brevity. 
     The first conducting material  1310  and the second conducting material  1320  are similar to one another in certain exemplary embodiments, but are different in other exemplary embodiments. According to one exemplary embodiment, the conducting materials  1310 ,  1320  are fabricated using aluminum foil; however, other suitable conducting materials can be used. The first conducting material  1310  is positioned adjacently above and in contact with the cutting surface  512 . The second conducting material  1320  is positioned adjacently below and in contact with the bottom surface  364 . The first conducting material  1310  and the second conducting material  1320  provide an area to which the first wire  1230  and the second wire  1240 , respectively, make electrical contact. Additionally, the first conducting material  1310  and the second conducting material  1320  assist in minimizing contact resistance with the cutting surface  512  and the bottom surface  364 , respectively, which is discussed in further detail below. In certain exemplary embodiments, the first conducting material  1310  and the second conducting material  1320  are the same shape and size; while in other exemplary embodiments, one of the conducting materials  1310 ,  1320  is a different shape and/or size than the other conducting material  1310 ,  1320 . 
     The first insulating material  1330  and the second insulating material  1340  are similar to one another in certain exemplary embodiments, but are different in other exemplary embodiments. According to one exemplary embodiment, the insulating materials  1330 ,  1340  are fabricated using paper; however, other suitable insulating materials, such as rubber, can be used. The first insulating material  1330  is positioned adjacently above and in contact with the first conducting material  1310 . The second insulating material  1340  is positioned adjacently below and in contact with the second conducting material  1320 . The first insulating material  1330  and the second insulating material  1340  provide a barrier to direct current flow only through a circuit  1305 , which is discussed in further detail below. In certain exemplary embodiments, the first insulating material  1330  and the second insulating material  1340  are the same shape and size; while in other exemplary embodiments, one of the insulating materials  1330 ,  1340  is a different shape and/or size than the other insulating material  1330 ,  1340 . Additionally, in certain exemplary embodiments, the insulating materials  1330 ,  1340  is larger in size than its corresponding conducting material  1310 ,  1320 . However, one or more of the insulating materials  1330 ,  1340  is either larger or smaller than its corresponding conducting material  1310 ,  1320  in alternative exemplary embodiments. 
     The Arbor Press  1350  includes an upper plate  1352  and a base plate  1354 . The upper plate  1352  is positioned above the base plate  1354  and is movable towards the base plate  1354 . In other exemplary embodiments, the base plate  1354  is movable towards the upper plate  1352 . The first insulating material  1330 , the first conducting material  1310 , the intermediately cleaned leached PDC cutter  600 , the second conducting material  1320 , and the second insulating material  1340  are positioned between the upper plate  1352  and the base plate  1354  such that the second insulating material  1340  is positioned adjacently above and in contact with the base plate  1354 . The upper plate  1352  is moved towards the base plate  1354  until the upper plate  1352  applies a downward load  1353  onto the cutting surface  512  of the intermediately cleaned leached PDC cutter  600 . When the downward load  1353  is applied, the first conducting material  1310  is deformed and adapted to the rough and very stiff cutting surface  512 , thereby minimizing contact resistance between the first conducting material  1310  and the cutting surface  512  and greatly improving the capacitance measurement consistency. At this time, the base plate  1354  also applies an upward load  1355  onto the bottom surface  364  of the intermediately cleaned leached PDC cutter  600 . When the upward load  1355  is applied, the second conducting material  1320  is deformed and adapted to the rough and very stiff bottom surface  364 , thereby minimizing contact resistance between the second conducting material  1320  and the bottom surface  364  and greatly improving the capacitance measurement consistency. In certain exemplary embodiments, the downward load  1353  is equal to the upward load  1355 . The downward load  1353  and the upward load  1355  is about one hundred pounds; however, these loads  1353 ,  1355  range from about two pounds to about a critical load. The critical load is a load at which the intermediately cleaned leached PDC cutter  600  is damaged when applied thereto. 
     In one exemplary embodiment, the second insulating material  1340  is positioned on the base plate  1354 , the second conducting material  1320  is positioned on the second insulating material  1340 , the intermediately cleaned leached PDC cutter  600  is positioned on the second conducting material  1320 , the first conducting material  1310  is positioned on the intermediately cleaned leached PDC cutter  600 , and the first insulating material  1330  is positioned on the first conducting material  1310 . The upper plate  1352  is moved towards the first insulating material  1330  until the downward load  1353  is applied onto the intermediately cleaned leached PDC cutter  600 . In an alternative exemplary embodiment, one or more components, such as the first insulating material  1330  and the first conducting material  1310 , are coupled to the upper plate  1352  prior to the upper plate  1352  being moved towards the base plate  1354 . Although an Arbor Press  1350  is used in the capacitance measuring system  1300 , other equipment capable of delivering equal and opposite loads to each of the cutting surface  512  and the bottom surface  364  of the intermediately cleaned leached PDC cutter  600  can be used in other exemplary embodiments. 
     One end of the first wire  1230  is electrically coupled to the positive terminal  1218  of the multi-meter  1210 , while the opposing end of the first wire  1230  is electrically coupled to the first conducting material  1310 , which thereby becomes electrically coupled to the cutting surface  512  of the intermediately cleaned leached PDC cutter  600 . In one exemplary embodiment, a clamp  1390  is coupled to the opposing end of the first wire  1230  which couples the first wire  1230  to the first conducting material  1310 . One end of the second wire  1240  is electrically coupled to the negative terminal  1219  of the multi-meter  1210 , while the opposing end of the second wire  1240  is electrically coupled to the second conducting material  1320 , which thereby becomes electrically coupled to the bottom surface  364  of the intermediately cleaned leached PDC cutter  600 . In one exemplary embodiment, a clamp (not shown), similar to clamp  1390 , is coupled to the opposing end of the second wire  1240 , which couples the second wire  1240  to the second conducting material  1320 . Hence, the circuit  1305  is completed using the multi-meter  1210 , the first wire  1230 , the first conducting material  1310 , the intermediately cleaned leached PDC cutter  600 , the second conducting material  1320 , and the second wire  1340 . The current is able to flow from the positive terminal  1218  of the multi-meter  1210  to the cutting surface  512  of the intermediately cleaned leached PDC cutter  600  through the first wire  1230  and the first conducting material  1310 . The current then flows through the intermediately cleaned leached PDC cutter  600  to the bottom surface  364  of the intermediately cleaned leached PDC cutter  600 . When the multi-meter  1210  is turned on, a voltage differential exists between the cutting surface  512  and the bottom surface  364 . The current then flows from the bottom surface  364  to the negative terminal  1219  of the multi-meter  1210  through the second conducting material  1320  and the second wire  1240 . The first insulating material  1330  and the second insulating material  1340  prevent the current from flowing into the Arbor Press  1350 . The capacitance measurement of the intermediately cleaned leached PDC cutter  600  is determined when the value displayed on the display  1216  reaches a peak value or remains constant for a period of time. The use, analyzing of the results, and other information regarding the capacitance measuring system  1300  is described in U.S. patent application Ser. No. 13/401,188, entitled “Use of Capacitance to Analyze Polycrystalline Diamond” and filed on Feb. 21, 2012, which has been incorporated by reference herein. 
     Referring back to  FIG. 11 , the by-product materials removal verification method  1100  proceeds to step  1150 . At step  1150 , removal of at least a portion of the by-product materials from the intermediately cleaned leached PDC cutter and measuring at least one capacitance value for at least one of the intermediately cleaned leached PDC cutter is continued until the capacitance value is at a stable lower limit capacitance value. The removal of at least a portion of the by-product materials has been described with respect to step  1130  and the measuring of the capacitance values has been described with respect to step  1140 . The stable lower limit capacitance value is the capacitance value of an intermediately cleaned leached PDC cutter at which the measured capacitance value does not further decrease upon further removal of by-product materials from the intermediately cleaned leached PDC cutter, i.e. further cleaning of the intermediately cleaned leached PDC cutter. The stable lower limit capacitance value is illustrated in  FIG. 14 . 
       FIG. 14  is a data scattering chart  1400  that shows the measured capacitance values  1411  for a plurality of intermediately leached and/or intermediately cleaned cutters  500 ,  600  at different cleaning cycles according to an exemplary embodiment. Referring to  FIG. 14 , the data scattering chart  1400  includes a cutter number axis  1420  and a capacitance axis  1410 . The cutter number axis  1420  includes the number of the cutters  1422  tested along with a cleaning cycle number  1423 . As shown, the first set of cutter numbers  1424  has not been cleaned of by-product materials  398  ( FIG. 5 ), the second set of cutter numbers  1425  has been cleaned of by-product materials  398  ( FIG. 5 ) through a first cleaning cycle  1427 , and the third set of cutter numbers  1426  has been cleaned of by-product materials  398  ( FIG. 5 ) through a second cleaning cycle  1428 . The capacitance axis  1410  includes values for the measured capacitance  1411 . A capacitance data point  1430  is obtained by measuring the capacitance of the intermediately leached and/or intermediately cleaned cutter  500 ,  600 , or intermediately leached and/or intermediately cleaned component, using the capacitance measuring system  1200  ( FIG. 12 ), the capacitance measuring system  1300  ( FIG. 13 ), or a similar type system. Each capacitance data point  1430  for each cutter number  1422 , with its respective cleaning cycle number  1423 , is plotted on the data scattering chart  1400 . Each cutter number  1422  has its capacitance measured a plurality of times. In some exemplary embodiments, five capacitance data points  1430  are obtained for each cutter number  1422 , however, the number of measurements is greater or fewer in other exemplary embodiments. In some exemplary embodiments, a twenty-five percentile marking  1450 , a fifty percentile marking  1452  (or average), and a seventy-five percentile marking  1454  are shown in the chart  1400  for each cutter number  1422 . The area between the twenty-five percentile marking  1450  and the seventy-five percentile marking  1454  is shaded. The amount of data scattering is ascertained using this data scattering chart  1400  and can be one or more of a differential between the highest and lowest capacitance measurements  1411  for each cutter number  1422 , a range between the twenty-five percentile marking  1450  and the seventy-five percentile marking  1454 , or some similar observation made from the data scattering chart  1400 . 
     According to  FIG. 14 , the first set of cutter numbers  1424 , which has not yet been cleaned, shows a larger data scattering of capacitance values  1411  than when compared to the second set of cutter numbers  1425 , which has been cleaned once for one hour using the by-products removal apparatus  700  ( FIG. 7 ), the by-products removal apparatus  800  ( FIG. 8 ), the by-products removal apparatus  900  ( FIG. 9 ), or the by-products removal apparatus  1000  ( FIG. 10 ). Further, the second set of cutter numbers  1425 , which has been cleaned once for one hour using the by-products removal apparatus  700  ( FIG. 7 ), the by-products removal apparatus  800  ( FIG. 8 ), the by-products removal apparatus  900  ( FIG. 9 ), or the by-products removal apparatus  1000  ( FIG. 10 ), shows a larger data scattering of capacitance values  1411  than when compared to the third set of cutter numbers  1426 , which has been cleaned a second time for another one hour using the by-products removal apparatus  700  ( FIG. 7 ), the by-products removal apparatus  800  ( FIG. 8 ), the by-products removal apparatus  900  ( FIG. 9 ), or the by-products removal apparatus  1000  ( FIG. 10 ). The third set of cutter numbers  1426  exhibit a minimal, or negligible, amount of data scattering of capacitance values  1411 . Thus, the capacitance values  1411  of the third set of cutter numbers  1426  is the stable lower limit capacitance value  1429  in this exemplary embodiment. However, it is possible, that if the third set of cutter numbers  1426  was to undergo an additional cleaning cycle, the capacitance values  1411  of the fourth set of cutter numbers (not shown) would be the stable lower limit capacitance value. When the stable lower limit capacitance value  1429  is reached, i.e. there is minimal to no data scattering of capacitance values  1411 , the intermediately cleaned leached PDC cutters  600  are effectively cleaned and verified as such. 
     Referring back to  FIG. 11 , the by-product materials removal verification method  1100  proceeds to step  1160 . At step  1160 , the by-product materials removal verification method  1100  ends. 
     Referring back to  FIG. 4 , the leaching method  400  proceeds to step  450 . At step  450 , the leaching process and the cleaning process continue iteratively and alternatingly on the intermediately cleaned leached PDC cutter  600  ( FIG. 6 ) until the depth of the leached portion  554  ( FIG. 5 ) reaches a desired leaching depth  353  ( FIG. 3 ). In some exemplary embodiments, however, the leaching process and the cleaning process are not performed alternatingly, but one or more processes are performed consecutively before the other process is performed. Once the desired leaching depth  353  is reached, a cleaned leached PDC cutter  1500  ( FIG. 15 ) is formed. As previously mentioned, cleaning the intermediately leached PDC cutter  500  ( FIG. 5 ) to form the intermediately cleaned leached PDC cutter  600  ( FIG. 6 ) allows the subsequent leaching process that is performed to be at a faster rate than if the intermediately leached PDC cutter  500  ( FIG. 5 ) was not cleaned. Hence, the cleaned leached PDC cutter  1500  ( FIG. 15 ) is formed in a shorter duration than if it were to be formed using a single leaching process and a single cleaning process on the PDC cutter  100  ( FIG. 1 ). 
       FIG. 15  shows a cross-sectional view of the cleaned leached PDC cutter  1500  having a PCD cutting table  1510  that has been leached and cleaned to the desired leaching depth  353  in accordance with an exemplary embodiment. The cleaned leached PDC cutter  1500  has been exposed to two or more leaching cycles and at least one cleaning cycle. Referring to  FIG. 15 , the cleaned leached PDC cutter  1500  includes the PCD cutting table  1510  coupled to the substrate  350 . The substrate  350  has been previously described above with respect to  FIG. 3  and therefore is not described again for the sake of brevity. The PCD cutting table  1510  is similar to the PCD cutting table  310  ( FIG. 3 ), but has had at least a portion of the by-product materials  398  removed from a cleaned leached layer  1554 . The cleaned leached layer  1554  is similar to leached layer  354  ( FIG. 3 ) except that at least a portion of the by-product materials  398  is removed from the leached layer  354  ( FIG. 3 ) to form the cleaned leached layer  1554 . Thus, PCD cutting table  1510  includes the cleaned leached layer  1554  and the unleached layer  356  which is disposed between the cleaned leached layer  1554  and the substrate  350 . The cleaned leached layer  1554  extends from the cutting surface  312 , which has been described above with respect to  FIG. 3 , towards the opposing surface  314 , which also has been described with respect to  FIG. 3 . In the cleaned leached layer  1554 , at least a portion of the cobalt  214  has been removed from within the interstitial spaces  212  ( FIG. 2 ) using at least one leaching process mentioned above when compared to the PCD cutting table  110  ( FIG. 1 ). Thus, the cleaned leached layer  1554  has been leached to the desired leaching depth  353 . However, as previously mentioned above, one or more by-product materials  398  were formed and deposited within some of the interstitial spaces  212  ( FIG. 2 ) in the leached layer  354  ( FIG. 3 ) during the leaching process. However, at least a portion of these by-product materials  398  are removed from the leached layer  354  ( FIG. 3 ), thereby forming leached layer  1554 . The process of removing the by-product materials  398  from the leached layer  354  ( FIG. 3 ) has been described above and is not repeated again herein. The unleached layer  356  has been previously described with respect to  FIG. 3  and therefore is not repeated for the sake of brevity. Although the boundary line  355  is formed between the cleaned leached layer  1554  and the unleached layer  356  and is depicted as being substantially linear, the boundary line  355  can be non-linear. 
     Referring back to  FIG. 4 , the leaching method proceeds to step  460 . At step  460 , the leaching method  400  ends. 
     A cleaned leached PDC cutter, which is substantially free of by-product materials, or catalyst metal salts, has a superior wear abrasion resistance with an increased thermal stability. Thus, the apparatus and methods disclosed herein minimizes the detrimental effects of the leaching reaction by-product materials. Further, a cleaning cycle occurring intermittently between successive leaching cycles allows the subsequent leaching cycle to proceed at a faster rate. Removing at least a portion of the by-product materials trapped within the leached portion has a beneficial effect of allowing the leaching solution to infiltrate into the polycrystalline structure faster and deeper. Although the conventional leaching method allows the leaching depth to reach about 300 microns only after long treatment periods, which are at times in excess of several days, the leaching method  400  allows the leaching depths to be reached in much shorter time periods or to reach the entire thickness of the polycrystalline structure in a few day. Conventional leaching process typically takes several weeks of treatment time when leaching the entire depth of the polycrystalline structure. 
     Although each exemplary embodiment has been described in detail, it is to be construed that any features and modifications that are applicable to one embodiment are also applicable to the other embodiments. Furthermore, although the invention has been described with reference to specific embodiments, these descriptions are not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention will become apparent to persons of ordinary skill in the art upon reference to the description of the exemplary embodiments. It should be appreciated by those of ordinary skill in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures or methods for carrying out the same purposes of the invention. It should also be realized by those of ordinary skill in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. It is therefore, contemplated that the claims will cover any such modifications or embodiments that fall within the scope of the invention.