PATENT DOCUMENT

Publication Number: US-11459668-B2
Application Number: US-202016952206-A
Country: US
Kind Code: B2

Title: Titanium part having an anodized layer

Abstract:
An enclosure for a portable electronic device can include a titanium substrate defining a textured surface and a nominal surface. The titanium substrate can include a first region that extends above the nominal surface and a second region adjacent to the first region and extending below the nominal surface. A separation distance between an apex of the first region and a bottom of a trough defined by the second region can be at least 1 micrometer. A metal oxide layer can overlay the trough defined by the second region.

Claims:
What is claimed is: 
     
       1. An enclosure for a portable electronic device, the enclosure comprising:
 a titanium substrate defining a textured surface and a nominal surface, the titanium substrate comprising:
 a first region that extends above the nominal surface; 
 a second region adjacent to the first region and extending below the nominal surface, a separation distance between an apex of the first region and a bottom of a trough defined by the second region being at least 1 micrometer; and 
 a metal oxide layer overlaying the trough defined by the second region; 
 
 wherein the titanium substrate further comprises a first grain structure and a second grain structure, the second region corresponding to a grain boundary that separates the first grain structure from the second grain structure. 
 
     
     
       2. The enclosure of  claim 1 , wherein the enclosure has a color having an a* value between −10 to 15 and a b* value between −35 to 30 in a CIE L*a*b* color space. 
     
     
       3. The enclosure of  claim 2 , wherein the color is dependent upon a thickness of the metal oxide layer. 
     
     
       4. The enclosure of  claim 3 , wherein the metal oxide layer has a thickness between 20 nanometers and 200 nanometers. 
     
     
       5. The enclosure of  claim 1 , wherein the metal oxide layer comprises an anodized layer formed from the titanium substrate. 
     
     
       6. The enclosure of  claim 1 , wherein the metal oxide layer comprises a first metal oxide layer having a first thickness that overlays the apex of the first region and a second metal oxide layer overlaying the trough defined by the second region, the second metal oxide layer having a second thickness different than the first thickness. 
     
     
       7. The enclosure of  claim 1 , wherein the first grain structure is oriented in a first orientation and the second grain structure is oriented in a second orientation different from the first orientation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Provisional Application No. 63/020,953, filed 6 May 2020, entitled “TITANIUM PART HAVING AN ANODIZED LAYER”, and is related to U.S. application Ser. No. 16/584,692, filed 26 Sep. 2019, entitled “TITANIUM PARTS HAVING A BLASTED SURFACE TEXTURE,” the contents of which are incorporated herein by reference in their entireties for all purposes. 
    
    
     FIELD 
     The described embodiments relate generally to techniques for forming a titanium part. More particularly, the described embodiments relate to systems and methods for forming an anodized layer within a textured surface of the titanium part. 
     BACKGROUND 
     Portable electronic devices can include various operational components (e.g., display, processor, antenna, etc.). Enclosures for these portable electronic devices can be formed of various metals (e.g., anodized aluminum, etc.) having a high amount of strength and stiffness to protect these operational components. Additionally, it is preferable to process these enclosures such as to impart these enclosures with an attractive surface finish. However, certain metals, although having a high amount of strength and stiffness, are also difficult to process to impart an attractive surface finish. Accordingly, there is a need to implement techniques for processing these specific types of metals. 
     SUMMARY 
     According to some aspects of the present disclosure, an enclosure for a portable electronic device can include a titanium substrate defining a textured surface and a nominal surface, the titanium substrate including a first region that extends above the nominal surface, a second region adjacent to the first region and extending below the nominal surface, a separation distance between an apex of the first region and a bottom of a trough defined by the second region being at least 1 micrometer, and a metal oxide layer overlaying the trough defined by the second region. 
     In some examples, the enclosure has a color having an a* value between −10 to 15 and a b* value between −35 to 30 in a CIE L*a*b* color space. The color is dependent upon a thickness of the metal oxide layer. The metal oxide layer has a thickness between 20 nanometers to 200 nanometers. The metal oxide layer can include an anodized layer formed from the titanium substrate. The metal oxide layer can include a first metal oxide layer having a first thickness that overlays the apex of the first region and a second metal oxide layer overlaying the trough defined by the second region, the second metal oxide layer can have a second thickness different than the first thickness. The titanium substrate can include a first grain structure and a second grain structure, and the second region corresponds to a grain boundary that separates the first grain structure from the second grain structures. The first grain structure is oriented in a first orientation and the second grain structure is oriented in a second orientation different from the first orientation. 
     According to some aspects, a portable electronic device can include a titanium substrate defining a textured surface having an average thickness value, the titanium substrate including a first region having a first thickness value less than the average thickness value, a second region adjacent to the first region and having a second thickness value greater than the average thickness value, and an anodized layer overlaying the first region, the anodized layer having a color having a* value between −10 to 15 and a b* value between −35 to 30 in a CIE L*a*b* color space. 
     In some examples, the color is a first color and the second region includes a second color different from the first color. The second color can be at least partially determined by the second thickness value. The first region defines a trough and a bottom of the trough is separated from an apex of the second region by a separation distance of at least 1 micrometer. The second region defines a planar external surface. The titanium substrate includes a first grain structure and a second grain structure, the first region corresponds to a grain boundary that separates the first grain structure from the second grain structure. The first grain structure can be oriented in a first orientation, and the second grain structure can be oriented in a second orientation different from the first orientation. 
     According to some aspects, an enclosure for a portable electronic device can include a titanium alloy substrate defining a textured surface and a nominal surface, the titanium alloy substrate including first surface regions extending above the nominal surface and second surface regions extending below the nominal surface, a first anodized layer overlaying the first surface regions, and a second anodized layer overlaying the second surface regions. 
     In some examples, the first anodized layer has a first average thickness, and the second anodized layer has a second average thickness different from the first average thickness. The first anodized layer has a first color proportional to the first average thickness and the second anodized layer has a second color proportional to the second average thickness. The surface coating has a surface color having an a* value between −10 to 15 and a b* value between −35 to 30 in a CIE L*a*b* color space. The surface color is at least partially determined by the first color and the second color. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements. 
         FIG. 1  illustrates perspective views of various devices having surfaces that can be processed using the techniques described herein. 
         FIGS. 2A-2F  illustrate cross-sectional views of various stages of processes for treating a surface of a metal part. 
         FIG. 3  illustrates an exemplary diagram of a metal part having a textured surface. 
         FIGS. 4A-4C  illustrate an exemplary cross-sectional view and an exemplary top view of a metal part, in accordance with some embodiments. 
         FIGS. 5A-5C  illustrate exemplary cross-sectional views and an exemplary top view of a metal part, in accordance with some embodiments. 
         FIGS. 6A-6C  illustrate exemplary cross-sectional views and an exemplary top view of a metal part, in accordance with some embodiments. 
         FIGS. 7A-7C  illustrate exemplary cross-sectional views and an exemplary top view of a metal part, in accordance with some embodiments. 
         FIGS. 8A-8C  illustrate exemplary cross-sectional views and an exemplary top view of a metal part, in accordance with some embodiments. 
         FIG. 9  illustrates an exemplary diagram of a metal part having an anodized coating, in accordance with some embodiments. 
         FIGS. 10A-10B  illustrate exemplary electron microscope images of a top view of a metal part having grain structures, in accordance with some embodiments. 
         FIGS. 11A-11B  illustrate exemplary electron microscope images of a top view of a metal part having grain structures, in accordance with some embodiments. 
         FIGS. 12A-12C  illustrate exemplary optical microscope images of a top view of a metal part having grain structures, in accordance with some embodiments. 
         FIG. 13A-13C  illustrate flowcharts of different methods for forming a metal part having an anodized coating, in accordance with some embodiments. 
         FIG. 14  illustrates an exemplary diagram of potential a* and b* values of metal parts having an anodized coating, in accordance with some embodiments. 
     
    
    
     Those skilled in the art will appreciate and understand that, according to common practice, various features of the drawings discussed below are not necessarily drawn to scale, and that dimensions of various features and elements of the drawings can be expanded or reduced to more clearly illustrate the embodiments of the present invention described herein. 
     DETAILED DESCRIPTION 
     Representative applications of methods and apparatus according to the present application are described in this section. These examples are being provided solely to add context and aid in the understanding of the described embodiments. It will thus be apparent to one skilled in the art that the described embodiments can be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the described embodiments. Other applications are possible, such that the following examples should not be taken as limiting. 
     In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the described embodiments, it is understood that these examples are not limiting; such that other embodiments can be used, and changes can be made without departing from the spirit and scope of the described embodiments. 
     Portable electronic devices can include various operational components (e.g., display, processor, antenna, etc.). Enclosures of these portable electronic devices are capable of protecting these operational components from physical damage, such as during a drop event. The enclosures can be formed of various metals, such as titanium or a titanium alloy. Additionally, titanium alloys can be colored using an anodization process in order to impart the titanium alloys with a color through interference coloring. In particular, the interference color imparts the titanium alloys with a color that is distinct from the natural color of titanium and dependent upon a thickness of the anodized layer. 
     Although the anodized layer can impart the titanium alloy with a different color, the surface of the anodized layer is particularly vulnerable to abrasion and mechanical stresses. The abrasion and mechanical stresses can wear against the surface of the anodized layer; thereby, prematurely removing the color of the anodized layer. 
     According to some embodiments, the durability of the color of the anodized layer can be improved by forming the anodized layer only within grooves or valleys of the external surface of the titanium alloy. In particular, the anodized layer can be recessed relative to the external surface of the titanium alloy. Beneficially, the anodized layer is generally protected from the same abrasion forces that the external surface is exposed to. 
     The embodiments described herein set forth techniques for texturizing the surface of a titanium alloy by exposing the titanium alloy to a selective etching process in order to selectively form microstructural peaks and valleys along the external surface of the titanium alloy. Thereafter, an anodized layer is formed to overlay the external surface of the titanium alloy. Subsequently, portions of the anodized layer are removed from the peaks by using a mechanical finishing process (e.g., blasting, etc.). As a result, the anodized layer generally overlays more of the valleys than the peaks so that the anodized layer is generally protected from abrasion forces. Beneficially, the durability of the color of the anodized layer is improved. 
     In some examples, the color of the anodized layer can be characterized according to CIE L*a*b* color-opponent dimension values. The L* color opponent dimension value is one variable in an L*a*b* color space. In general, corresponds to an amount of lightness. L*=0 represents an extreme black while L*=100 represents white. In general, a* indicates amounts of red color and green color in a sample. A negative a* value indicates a green color, while a positive a* value indicates a red color. Accordingly, samples having a positive a* value will indicate that more red than green is present. In general, b* indicates amounts of blue color and yellow color in a sample. A negative b* value indicates a blue color, while a positive b* value indicates yellow color. Accordingly, samples having a positive b* value will indicate more yellow than blue is present. 
     According to some embodiments, an enclosure for a portable electronic device is described. The enclosure includes a surface coating having a titanium substrate having a textured surface including a nominal surface, the textured surface including (i) a first region that extends above the nominal surface, and (ii) a second region adjacent to the first vertical region and extending below the nominal surface, where a separation distance between an apex of the first region and a trough of the second region is at least 1 micrometer. The surface coating further includes a metal oxide layer overlaying the trough of the second region. 
     These and other embodiments are discussed below with reference to  FIGS. 1-14 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1  illustrates various portable devices that can be processed using the techniques as described herein. The techniques as described herein can be used to process metallic surfaces (e.g., titanium substrate, titanium alloy substrate, etc.) of enclosures of portable electronic devices.  FIG. 1  illustrates a smartphone  102 , a tablet computer  104 , a smartwatch  106 , and a portable computer  108 . According to some embodiments, the metallic surfaces can refer to a metal substrate that is capable of being anodized. In some examples, the metal substrate can include a titanium alloy substrate. Notably, the titanium alloy substrate can include a titanium alloy having different grain structures of alpha and beta metallic phases. 
     Titanium and its alloys are characterized as having a high specific strength and stiffness, which makes titanium an attractive choice for the enclosures of the exemplary portable electronic devices described herein. For example, titanium alloys, such as Ti-6Al-4V can have a Vickers hardness number of from about 300 Hv to about 350 Hv. Additionally, certain alloying elements can be incorporated into the titanium to further increase the hardness. Thus, titanium alloy components, such as enclosures, can protect internal operational components carried by the enclosures, for example, when these portable electronic devices are dropped, scratched, chipped, or abraded. Accordingly, described herein are several examples for texturizing an external surface of the titanium alloy substrate. 
       FIGS. 2A-2F  illustrate cross-sectional views of various stages of process for treating a surface of a metal part as described herein, for example, to form an anodized coating.  FIG. 2A  illustrates a metal part  200  prior to undergoing a texturizing process. In some examples, the metal part  200  includes a metal substrate  204  that is capable of being anodized. The metal substrate  204  includes a titanium alloy having a single grain structure (alpha phase) or multi-phase structure (alpha and beta phases). 
     In some embodiments, the metal substrate  204  has a thickness that is suitable for undergoing an etching process. Indeed, the etching process can remove an amount of material from an upper region of the metal substrate  204  (i.e., at least 1 micrometer from the external surface). In some embodiments, the metal part  200  has a near net shape of a final part, such as the enclosures of the portable electronic devices  102 ,  104 ,  106 , and  108 . In some examples, the external surface  202  of the metal part  200  is characterized as having a planar shape or a generally planar shape, as illustrated in  FIG. 2A . In some examples, the metal part  200  is characterized as having a uniform thickness or generally uniform thickness. 
     According to some embodiments, prior to the surface texturizing process, the metal substrate  204  can be subjected to a machining process in order to impart the metal substrate  204  with a final shape. Thereafter, the metal substrate  204  can be wet-sanded to remove any machining marks in order to impart the external surface  202  with a fine, uniform, smooth finish. Thereafter, the external surface defined by the metal substrate  204  can be optionally polished to achieve a uniform high gloss finish. 
       FIG. 2B  illustrates a textured metal part  210  subsequent to undergoing a texturizing process in order to roughen and/or texturize the external surface  202  of the metal substrate  204 , in accordance with some embodiments. According to some examples, the external surface  202  can be texturized by exposing the external surface  202  to a mechanical brushing process. For example, the external surface  202  is brushed by exposure to a brushing media (e.g., grinding wheel). Indeed, the process for forming a metal part having an anodized coating as described with reference to  FIGS. 2A-2F  is performed with respect to a mechanical brushing process. However, the metal substrate  204  can also be texturized using a chemical etching process, as will be described in greater detail with reference to  FIGS. 6A-6C . 
     As a result of the texturizing process, the external surface  202  of the textured metal part  210  has a surface roughness defined as an average amplitude of vertical deviations (positive and negative deviations) from a nominal surface of the textured metal part  210  over a specified length surface. More specifically, the vertical deviations from the nominal surface can include positive vertical deviations in the form of peaks  212  that alternate with negative vertical deviations in the form of valleys  214  (also referred to as troughs). In some examples, the alternating positive and negative vertical deviations from the nominal surface can be randomly distributed or evenly distributed from each other. In some examples, the nominal surface can be an imaginary planar surface that has a single height or position equivalent to the average height or position of the textured surface. Beneficially, using the mechanical brushing process, the fraction of the external surface  202  including peaks and valleys is more repeatable and can be more precisely controlled relative to a chemical etching process. 
     According to some examples, an apex (A) of the peak  212  is separated from a bottom (T) of the valley  214  by a separation distance (Y 1 ) of at least 1 micrometer or greater. In some examples, the separation distance (Y 1 ) is between 1 micrometer to 10 micrometers. As understood by those of ordinary skill in the art, the separation distance between the apex (A) of the peak  212  and the bottom (T) of the valley  214  is preferably at least 1 micrometer or greater in order to accommodate for an anodized layer that will be formed to overlay the valley  214 . In some examples, the surface roughness of the external surface  202  of the textured metal part  210  is characterized according to the separation distance (Y 1 ) between the apex (A) of the peak  212  and the bottom (T) of the valley  214 . As used herein, the apex of a surface can be used to refer to the point or region of a surface that is disposed furthest from a nominal surface in a direction perpendicular to the nominal surface. 
     As illustrated in  FIG. 2B , the alternating peaks  212  and valleys  214  can be randomly distributed from each other. The apex (A) of the peaks  212  and the bottoms (T) of the valleys  214  can have varied depths of at least 1 micrometer to 5 micrometers. In some examples, the mechanical brushing process can roughen the external surface  202  of the metal substrate  204  in a controlled manner to result in fine-scale surface roughness. 
     According to some embodiments, the textured metal part  210  can also be formed by using a micro-arc oxidation process. Techniques for using micro-arc oxidation to texturize an external surface of a titanium or titanium alloy substrate are described with reference to U.S. application Ser. No. 16/584,692 entitled “TITANIUM PARTS HAVING A BLASTED SURFACE TEXTURE,” filed Sep. 26, 2019, the contents of which are incorporated herein by their entirety for all purposes. 
       FIG. 2C  illustrates an anodized metal part  220  subsequent to undergoing an anodization process, in accordance with some embodiments. According to some examples, the textured metal part  210  is exposed to an anodization process that involves exposing the metal substrate  204  to an anodization process (e.g., between 25 volts-35 volts) that causes an anodized layer  224  to form from the metal substrate  204 . The anodized layer  224  overlays the entire external surface  202  of the textured metal part  210 . 
     As illustrated in  FIG. 2C , the anodized layer  224  overlays the peaks  212  and the valleys  214 ; thereby, increasing a separation distance between the apex (A) of the peaks and the bottoms (T) of the valleys  214 . For example,  FIG. 2C  illustrates that the separation distance (Y 2 ) between the apex (A) of the peak  212  of the anodized layer  224  and the bottom (T) of the valley  214  of the metal substrate  204  is greater than the separation distance (Y 1 ). According to some examples, the apex (A) of the peaks  212  are rounded caused by preferential anodization of the peaks  212  relative to the valleys  214  during the anodization of the metal substrate  204 . The thickness of the anodized layer  224  can vary between 20 nanometers and 200 nanometers. 
     The anodized layer  224  can impart the anodized metal part  220  with a thin-film interference color. As is understood by those of ordinary skill in the art, different thin-film interference colors are proportional to the thicknesses of the anodized layer  224 . The amplitude of the anodizing voltage can affect the thickness of the anodized layer  224 . 
       FIG. 2D  illustrates a processed anodized part  230  subsequent to the anodized metal part  220  undergoing a mechanical finishing process, in accordance with some embodiments. According to some examples, the mechanical removal process includes at least one of a blasting, buffing or polishing process. According to some embodiments, the external surface  202  of the anodized metal part  220  can be subjected to the mechanical removal process order to preferentially remove more metallic material from the peaks  212  than the valleys  214 . For example,  FIG. 2D  illustrates a material removal line (RL) that denotes different regions of peaks  212  and valleys  214  that are mechanically removed subsequent to the blast mechanical removing process. In some examples, the amount of the regions of the peaks  212  and valleys  214  that is removed according to the removal line (RL) is based on at least one of a duration, intensity, size of blasting particles that are utilized during the blasting process. In some instances, it can be desirable to remove a greater amount of the peaks  212  relative to the valleys  214  in order to achieve a smoother surface having a higher gloss finish. In some examples, the size of the blasting media is greater than the sizes of the peaks  212 . 
     As illustrated in  FIG. 2D , regions of the peaks  212  and the valleys  214  are removed subsequent to the blasting process as indicated by the removed peaks (P r ) and removed valleys (V r ). In other words, the separation distance between apex (A) of the peaks  212  of the anodized layer  224  and the bottoms (T) of the valleys  214  is reduced subsequent to the blasting process. In some embodiments, blasting the external surface  202  can reduce surface asperities, which tends to favor reducing a greater amount of the peaks  212  relative to the valleys  214 . As a result, the external surface  202  of the processed anodized part  230  is more attenuated or flatter relative to the external surface  202  of the anodized metal part  220 . The portions of the anodized layer  224  that overlay the valleys  214  and are recessed relative to the uppermost portions of the external surface  202  are generally resistant to abrasion. Accordingly, the interference color imparted by these portions of the anodized layer are very durable relative to the uppermost portions of the external surface  202 . 
     As illustrated in  FIG. 2E , the separation distance between the apex (A) of the peaks  212  and the bottom (T) of the valleys  214  is reduced to (Y 3 ) where (Y 3 )&lt;(Y 2 ). In some examples, the separation distance (Y 3 ) between the apex (A) of the peaks  212  and the bottom (T) of the valleys  214  is at least 1 micrometer or greater. In some examples, the separation distance (Y 3 ) is 2 to 3 micrometers or greater. In some examples, the separation distance (Y 3 ) is no greater than 10 micrometers. 
       FIG. 2F  illustrates an oxidized part  240  subsequent to exposing the processed anodized part  230  to an additional process, in accordance with some embodiments. The processed anodized part  230  can be exposed to the additional process to form multiple colors (i.e. non-natural titanium colors). In particular, the exposed regions of the metal substrate  1102  corresponding to the removed peaks (Pr) and removed valleys (Vr) can be subjected to an additional anodization process to form a metal oxide layer  242 . Alternatively, the oxidized part  240  is formed by exposing the processed anodized part  230  to a process that can include a physical vapor deposition process or other deposition process. In some examples, a deposited layer can then be subjected to further processing, for example to form a metal oxide layer  242 . The metal oxide layer  242  can overlay more of the peaks  212  than the valley  214  that were exposed as a result of the mechanical finishing process. In particular, the metal oxide layer  242  only overlays those peaks  212  and/or valleys  214  that are exposed (i.e., not overlaid by the anodized layer  224 ) subsequent to the mechanical finishing process. The metal oxide layer  242  can impart an additional color (e.g., black, gold, etc.) to the oxidized part  240 . The metal oxide layer  242  can increase the surface hardness for improved abrasion resistance. In some examples, the metal oxide layer  242  has a thickness between 10 nanometers to 200 nanometers. 
     In some examples, the metal oxide layer  242  can have a different thickness than the anodized layer  224 ; thereby, imparting different thin-film interference colors across the surface of the oxidized part  240 . In particular, the anodized layer  224  is associated with a first color and the metal oxide layer  242  is associated with a second color different than the first color. The combined color of the oxidized part  240  is based upon the colors of the anodized layer  224  and the metal oxide layer  242 , which is dependent upon their respective differences in thickness. Additionally, a person viewing the external surface  202  of the oxidized part  240  from different angles can perceive different colors. The difference in perceived colors is due to the respective angularity or directionality of the peaks  212  and valleys  214 . As described herein, the angularity can refer to an orientation of the peaks and valleys  214  with respect to a surface normal of the external surface  202 . 
       FIG. 3  illustrates an exemplary diagram of a metal part  300  having a textured surface, in accordance with some embodiments. According to some examples, the metal part  300  can refer to any one of the textured metal part  210 , the anodized metal part  220 , the processed anodized part  230  or the oxidized part  240 . For simplicity of illustration, individual structural details of the textured metal part  210 , the anodized metal part  220 , the processed anodized part  230  or the oxidized part  240  are not illustrated with reference to the metal part  300  of  FIG. 3 , as they were previously described with reference to  FIGS. 2A-2F . 
     The metal part  300  can include peaks  212  and valleys  214  along an actual surface (AS), where the peaks  212  and valleys  214  are defined as positive and negative vertical deviations from a nominal surface (NS), respectively. As shown in  FIG. 3 , the nominal surface (NS) is represented as a nominal longitudinal line that spans the length (L) of the metal part  300 . The actual surface (AS) includes positive deviations (Pd) that extend above the nominal line and negative deviations (Nd) that extend below the nominal line. In some embodiments, the positive deviations (Pd) can be referred to as first vertical region that extends above the nominal surface (NS) and the negative deviations (Nd) can be referred to as a negative vertical region that extends below the nominal surface (NS). 
     According to some embodiments, the metal part  300  is characterized as having an average thickness value (ATv). The average thickness value can correspond to an average thickness of the metal part  300  that takes into account the amplitudes of the positive and negative deviations (Pd, Nd). Additionally, the positive deviations (Pd) are characterized as having a first average thickness value (ATp) and the negative deviations (Nd) are characterized as having a second average thickness value (ATn). The positive deviations (Pd) take into account an average thickness of all of the peaks of the metal part  300  from the bottom surface  206  of the metal substrate  204  extending to the apex (A) of each peak  212 . The negative deviations (Nd) take into account an average thickness of all of the valleys  214  of the metal part  300  from the bottom surface  206  of the metal substrate  204  extending to the bottom (T) of each valley  214 . As illustrated in  FIG. 3 , the first average thickness value (ATp) of the positive deviations (Pd) is greater than the second average thickness value (ATv) of the metal part  300 . Additionally, the second average thickness value (ATn) of the negative deviations (Nd) is less than the average thickness value (ATv) of the metal part  300 . Although not illustrated in  FIG. 3 , the positive deviations (Pd) and the negative deviations (Nd) also take into account the thicknesses of the anodized layer  224  and the metal oxide layer  242 . 
       FIGS. 4A-4C  illustrate exemplary cross-sectional views and an exemplary top view of a metal part, in accordance with some embodiments.  FIG. 4A  illustrates a cross-sectional view of a metal part  400 . The metal part  400  can include a titanium alloy having different grain structures. For example, these grain structures can be the result of incorporating different alloying elements into the titanium alloy such as molybdenum, silicon, vanadium, and the like.  FIG. 4A  illustrates that the external surface  402  of the metal part  400  is planar or generally planar. 
       FIG. 4B  illustrates a magnified cross-sectional view of a region of the metal part  400 . As shown in  FIG. 4B , the metal part  400  includes a first grain structure  410  separated from a second grain structure  412  by a grain boundary  414 . The first and second grain structures  410 ,  412  can have different etching and anodization rates.  FIG. 4C  illustrates a magnified top view of the region of the metal part  400 . As shown in  FIG. 4C , the second grain structure  412  is separated from first grain structures  410  by the grain boundary  414 . In some examples, the first and second grain structures  410 ,  412  can be associated with an alpha phase. The alpha phase refers to a hexagonal close-packed crystalline structure. 
       FIGS. 5A-5C  illustrate exemplary cross-sectional views and an exemplary top view of a treated metal part, in accordance with some embodiments. In particular,  FIG. 5A  illustrates a treated metal part  500 . In particular, the metal part  400  is exposed to a treatment process to form the treated metal part  500 . In some examples, the treatment process involves exposing the metal part  400  to specific heat temperatures and soak times above a beta phase transus temperature (beta annealing process) for the purposes of controlling the sizes of the grain structures  410 ,  412 . In some examples, the heat treatment involves exposure to a temperature of 700° C. to 1050° C. for a duration of 1 to 2 hours. The beta phase refers to a body-centered cubic structure. Transformation of the alpha phase to the beta phase can occur upon heating the metal part  400 . 
       FIG. 5B  illustrates a region of the metal substrate  404  where the sizes of the grain structures  410 ,  412  can be controlled and adjusted using the treatment process, such as to increase or decrease the sizes of the grain structures  410 ,  412 . In particular, the amount of fraction of the valleys formed within the external surface  402  is dependent upon the sizes of the grain structures  410 ,  412 . 
     Additionally, the treatment process can include precipitating a secondary phase (e.g., alpha phase) at the grain boundary  414  to form precipitates. As a result, the grain structures  410 ,  412  are associated with dual phases (alpha, beta). The precipitation step can increase a hardness of the titanium alloy. As a result, the grooves  506  form along the periphery of the grain boundary  414 , as illustrated with respect to  FIG. 5C .  FIG. 5C  illustrates a magnified top view of the region of the treated metal part  500 . 
     Beneficially, adjusting the size of the grain structures  410 ,  412  in conjunction with a chemical etching process enables a much finer level of control and granularity of the aspect ratio of the grain structures  410 ,  412  not otherwise achievable using the mechanical finishing process (e.g., brushing, etc.). As a result, the sizes of the resulting valleys and peaks of the textured metal part are much more controllable and can lend to forming smaller peaks and valleys than otherwise possible using mechanical finishing processes. However, forming the peaks and valleys using a brushing process lends to more repeatable shapes of peaks and valleys with more of a linear size relative to those peaks and valleys formed through a chemical etching process. 
       FIGS. 6A-6C  illustrate exemplary cross-sectional views and an exemplary top view of a textured part, in accordance with some embodiments.  FIG. 6A  illustrates a cross-sectional view of a textured part  600 . In particular, the treated metal part  500  is exposed to an etching process to form the textured part  600 . In some examples, the etching process includes a chemical etching process (e.g., Kroll&#39;s etch) to selectively etch the grain boundary  414  of the grain structures having the alpha phase at a different etchant rate than the grain structures having the beta phase. The grain structures having the alpha phase will etch at a greater rate than those grain structures having the beta phase, thereby causing valleys  614  to form in regions of the metal substrate  404  corresponding to the alpha phase. Additionally, the valley  614  can form in a region of the metal substrate  404  corresponding to the grain boundary  414 , as illustrated by  FIG. 6B .  FIG. 6C  illustrates a magnified top view of the region of the textured part  600  where the valleys  614  forms over the region corresponding to the grain boundary  414 . 
       FIGS. 7A-7C  illustrate exemplary cross-sectional views and an exemplary top view of an anodized part, in accordance with some embodiments.  FIG. 7A  illustrates a cross-sectional view of an anodized part  700 . In particular, the textured part  600  is exposed to an anodizing process to form the anodized part  700 . As illustrated in  FIG. 7B , the anodized part  700  includes an anodized layer  702  that overlays the peaks  612  and valleys  614  of the metal substrate  404 . In some examples, the shape of the anodized layer  702  conforms to a shape of the peaks  612  and valleys  614 . For example,  FIG. 7B  illustrates a region of the anodized part  700  where the shape of the anodized layer  702  corresponds to the shape of the peaks  612  and valleys  614 .  FIG. 7C  illustrates a magnified top view of the region of the anodized part  700 . 
       FIGS. 8A-8C  illustrate exemplary cross-sectional views and an exemplary top view of a processed anodized part, in accordance with some embodiments.  FIG. 8A  illustrates a cross-sectional view of the processed anodized part  800 . In particular, the processed anodized part  800  is exposed to a mechanical finishing process, such as a blasting, lapping or polishing process in order to preferentially remove more of portions of the anodized layer  702  overlaying the peaks  612  than the valleys  614 . As a result, more of the anodized layer  702  overlays the valleys  614  than the peaks  612 . 
       FIG. 8B  illustrates a region of the processed anodized part  800  that illustrates that more of the anodized layer  702  overlays the valleys  614  than the peaks  612 . Beneficially, this structure imparts the anodized layer  702  of the processed anodized part  800  with greater durability than traditionally anodized structures because portions of the anodized layer  702  are recessed below the uppermost regions of the peaks  612  and are less susceptible to being scratched or abraded.  FIG. 8C  illustrates a magnified top view of the region of the processed anodized part  800 . 
       FIG. 9  illustrates an exemplary diagram of a metal part having an anodized coating, in accordance with some embodiments. As described herein, the global color of an anodized part having a textured surface can be controlled by adjusting the relative grain sizes and grain structures. 
       FIG. 9  illustrates an exemplary diagram of the oxidized part  240 , as described with reference to  FIG. 2F . The oxidized part  240  includes a first valley  214 — 1 , a second valley  214 — 2 , and a third valley  214 — 3 .  FIG. 9  illustrates that the oxidized part  240  includes an anodized layer  224  overlays each of the first, second, and third valleys  214 — 1 ,  2 ,  3 . 
     The first, second, third valleys  214 — 1 ,  2 ,  3  of the oxidized part  240  of  FIG. 9  can have different angularity or directionality with respect to each other. In other words, the first valley  214 — 1  can be oriented in a first angle with respect to a surface normal of the external surface  202 , the second valley  214 — 2  can be oriented in a second angle different than the first angle with respect to the surface normal of the external surface  202 , and the third valley  214 — 3  can be oriented in a third angle different than the first and/or second angles with respect to the surface normal of the external surface  202 . As a result, the oxidized part  240  can be perceived as a different color depending upon the viewing angle of the oxidized part  240 . 
       FIG. 9  illustrates that an observer can perceive a first color (P 1 ) when viewing the external surface  202  of the oxidized part  240  according to a first angle (θ 1 ). In particular, the first color (P 1 ) can be attributed to the observer not being able to see the anodized layer  224  overlaying the first and second valleys  214 — 1 ,  2  as they can be obscured by the metal oxide layer  242 . Additionally, the observer can perceive a second color (P 2 ) different than the first color (P 1 ) when viewing the external surface  202  of the oxidized part  240  according to a second angle (θ 2 ) different than the first angle (θ 1 ). In particular, the second color (P 2 ) can be attributed to the observer not being able to see the first valley  214 — 1  as the anodized layer  224  overlaying the first valley  214 — 1  can be obscured by the metal oxide layer  242 . Additionally, the observer can perceive a third color (P 3 ) different than the first and second colors (P 1 , P 2 ) when viewing the external surface  202  of the oxidized part  240  according to a third angle (θ 3 ) different than the first and second angles (θ 1 , θ 2 ). In particular, the third color (P 3 ) can be attributed to the observer being able to see the respective anodized layer  224  overlaying the first, second, and third valleys  214 — 1 ,  2 ,  3 . 
     In some examples, the first, second, and third colors (P 1 , P 2 , P 3 ) can be characterized as having an a* value between −10 to 15 and a b* value between −35 to 30. Although the processed anodized part  230  is not described herein, it should also be noted that an observer can also perceive different colors of the processed anodized part  230  according to the particular viewing angle. In contrast to the oxidized part  240 , the processed anodized part  230  can include a combination of the interference color of the anodized layer  224  and of the exposed peaks  212  and/or valleys  214 . In particular, the exposed peaks  212  and/or valleys  214  have a natural titanium color. 
       FIGS. 10A-10B  illustrate exemplary electron microscope images of top views of a metal part having grain structures, in accordance with some embodiments. In particular,  FIGS. 10A-10B  illustrate a treated metal part  1000  and a textured part  1002 , respectively.  FIG. 10A  illustrates a treated metal part  1000  that involves exposing a metal substrate—e.g., the metal substrate  404 —to a treatment process such as exposing the metal substrate  404  to a specific heat temperature in order to control the size of grain structures  1010 ,  1012 . In some examples, the heat treatment involves exposure to a temperature between 700° C. to 1050° C. for a duration of 1 to 2 hours. The grain structures  1010 ,  1012  can be separated by a grain boundary  1014 . The treatment process can include precipitating a secondary phase (e.g., alpha phase) at the grain boundary  1014 . As a result, the grain structures  1010 ,  1012  are associated with dual phases (alpha, beta). As a result of the alpha precipitation, grooves  1016  (also referred to as valleys) form on and/or along the periphery of the grain boundary  1014 . The grooves  1016  can refer to a shallow dimple or gap that forms along an external surface of the treated metal part  1000 , as shown in region (a). 
       FIG. 10B  illustrates the region (a) of the textured part  1002 . The textured part  1002  is formed by exposing the treated metal part  1000  to an etching process. The etching process causes selective etching of the external surface of the treated metal part  1000  in accordance with the alpha and beta phases of the grain structures  1010 ,  1012 . In particular, the chemical etching process (e.g., Kroll&#39;s etch) selectively etches the alpha phase relative to the beta phase so as to form grooves  1016  (or valleys) in regions of the external surface corresponding to the grain boundary  1014 . The grooves  1016  can have a depth of 2 micrometers to 3 micrometers and a width of several tens of micrometers. 
       FIGS. 11A-11B  illustrate exemplary electron microscope images of top views of a metal part having grain structures, in accordance with some embodiments. In particular,  FIGS. 11A-11B  illustrate a metal part  1100  and a textured part  1102 , respectively.  FIG. 11A  illustrates a metal part  1100  having grain structures  1110 ,  1112 . The grain structures  1110  and  1112  are separated by a grain boundary  1114 , as depicted in region (b). 
       FIG. 11B  illustrates the region (b) of the textured part  1102 . The textured part  1002  is formed by exposing the metal part  1100  to a selective etching process. The selective etching process causes selective etching of the external surface of the metal part  1100 . In particular, the chemical etching process (e.g., Kroll&#39;s etch) selectively etches the alpha phase relative to the beta phase so as to form grooves  1116  (or valleys) in regions of the external surface corresponding to the grain boundary  1114 . The grooves  1116  can have a depth of 7 micrometers to 8 micrometers and a width between 5 to 10 micrometers. In contrast to the grooves  1016  of  FIG. 10B , the grooves  1116  are deeper. 
       FIGS. 12A-12C  illustrate exemplary optical microscope images of top views of a metal part having grain structures, in accordance with some embodiments.  FIG. 12A  illustrates a top view of a textured part  1200 —e.g., the textured part  210 —according to some embodiments. The textured part  1200  includes grain structures  1210  and  1212  separated by a grain boundary  1214 . The grain structures  1210  and  1212  can be associated with alpha and beta phases, respectively. 
       FIG. 12B  illustrates a top view of an anodized part  1202 —e.g., the anodized part  220 —according to some embodiments. The anodized part  1202  includes an anodized layer  1216  that overlays the grain structures  1210 ,  1212 . In some examples, the anodized part  1202  is formed by exposing the textured part  1200  to different anodizing voltages such as between 1 volt to 70 volts. The thickness of the anodized layer  1216  can be directly proportional to the amplitude of the anodizing voltage. Additionally, the interference color of the anodized layer  1216  can be related to the thickness. 
       FIG. 12C  illustrates a top view of a processed anodized part  1204 —e.g., the processed anodized part  230 —according to some embodiments. The processed anodized part  230  is formed by exposing the anodized part  1202  to a mechanical finishing process such as a blasting process. The blasting process can reduce the portion of the anodized layer  1216  overlaying the peaks while maintain a greater amount of the anodized layer  1216  overlaying the grooves (or valleys). 
       FIG. 13A-13C  illustrate flowcharts of different methods for forming a metal part having an anodized coating, in accordance with some embodiments. 
       FIG. 13A  illustrates a method  1300  for forming a metal part having an anodized layer, according to some embodiments. As illustrated in  FIG. 13A , the method  1300  begins at step  1302  by exposing an external surface  202  of a metal substrate  204  to a texturizing process to form a textured external surface. The texturizing process can include a mechanical brushing process such as using brushing media. As a result of the texturizing process, the external surface  202  can be modified from a planar external surface to form peaks  212  and valleys  214 . The peaks  212  and  214  can be randomly distributed. 
     At step  1304 , a first anodized layer—e.g., the anodized layer  224 —is formed to overlay the textured external surface. In some examples, an optical detection system can be utilized to determine whether the first anodized layer has a color that corresponds to a desired interference color. 
     At step  1306 , a portion of the first anodized layer is removed by using a mechanical finishing process (e.g., blasting, etc.) such as to expose peaks  212  of the textured external surface. In some embodiments, more of the peaks  212  of the textured external surface can be exposed than the valleys  214 . The optical detection system can be used to determine whether the color of the processed anodized part matches a desired color, then the mechanical finishing process can either continue until the desired color is achieved or end. Notably, the color of the processed anodized part can reflect a combination of the anodized layer and the color of the exposed peaks and/or valleys (e.g., natural titanium color). At step  1308 , a second anodized layer—e.g. the metal oxide layer  242 —can be optionally formed to overlay the exposed peaks and/or valleys of the textured external surface. 
       FIG. 13B  illustrates a method  1310  for forming a metal part having an anodized layer, according to some embodiments. As illustrated in  FIG. 13B , the method  1310  begins at step  1312  by optionally subjecting a titanium alloy—e.g., the metal substrate  404 —to a heat treatment process to adjust grain sizes of grain structures  410 ,  412  of the metal substrate  404 . Notably, adjusting the grain sizes provides a level of control for adjusting the amount of fraction of the external surface and the aspect ratio of the grooves (or valleys) formed in the external surface during the etching process. For example, it can be possible to form a series of peaks and valleys separated by a generally uniform or uniform distance apart by controlling the amount of fraction and/or the sizes of the grooves. 
     At step  1314 , the method  1310  involves optionally precipitating a secondary phase at a grain boundary  414  disposed between the grain structures  412 ,  412  of the metal substrate  404 . The metal substrate  404  is exposed to an intermediate heat treatment process to precipitate an alpha phase at the one or more grain boundaries  414  of the metal substrate  404 . 
     At step  1316 , the method  1310  involves exposing an external surface  402  of the metal substrate  404  to an etching process to form a textured part  600  having a textured external surface. In some examples, it should be noted that titanium alloys and/or titanium are very hard substances that can be difficult to process using conventional mechanical processes. Accordingly, adjusting the grain sizes of the grain structures  410 ,  412  prior to the chemical etching process can facilitate in forming a tunable amount of fractions of peaks  612  and valleys  614  along the external surface  402 . A detection system such as Electron Backscatter Diffraction (EBSD) can be used to scan the surface of the textured part  600  to detect grain boundaries and grain orientations. 
     At step  1318 , a first anodized layer—e.g., the anodized layer  702 —can be formed such as to overlay the peaks  612  and valleys  614  of the textured external surface. In some examples, an optical detection system can be utilized to determine whether the anodized layer has a color that corresponds to a desired color. 
     At step  1320 , a portion of the first anodized layer is removed by using a mechanical finishing process (e.g., blasting, polishing, etc.) such as to expose at least some of the peaks  612  of the textured external surface such as to form a processed anodized part  700 . The optical detection system can be used to determine whether the color of the processed anodized part  700  matches a desired color, then the mechanical finishing process can either continue or end. Notably, the color of the processed anodized part  700  can reflect a combination of the anodized layer and the color of the exposed peaks and/or valleys (e.g., natural titanium color). 
     At step  1322  involves optionally forming a second anodized layer—e.g., the metal oxide layer  242 —that overlays the exposed peaks of the textured external surface as part of forming an oxidized part  800 . Notably, the color of the oxidized part  800  can reflect a combination of the anodized layer and the metal oxide layer. 
       FIG. 13C  illustrates a method  1330  for forming a metal part having an anodized coating, according to some embodiments. As illustrated in  FIG. 13C , the method  1330  begins at step  1332  where a metal substrate—e.g., the metal substrate (e.g., titanium or alloy thereof, etc.)—is subject to a processing step. In some examples, the processing step includes blasting the external surface of the metal substrate to form a matte surface finish and/or polishing the external surface to form a high—gloss surface finish. 
     At step  1334 , a metal oxide layer is formed over the external surface of the metal substrate by applying an electrochemical oxidation process (e.g., micro arc oxidation, etc.). Techniques for using micro-arc oxidation to texturize an external surface of a titanium or titanium alloy substrate are described with reference to U.S. application Ser. No. 16/584,692 entitled “TITANIUM PARTS HAVING A BLASTED SURFACE TEXTURE,” filed Sep. 26, 2019, the contents of which are incorporated herein by their entirety for all purposes. In conjunction with performing the electrochemical oxidation process, the external surface of the metal substrate is roughened to form a texturized surface having alternating peaks and valleys. According to some examples, the electrochemical oxidation process includes applying a high-voltage anodizing process to the metal oxide layer that causes plasma discharge events. The plasma discharge events cause portions of the metal oxide layer to melt, thereby resulting in a crystalline structure. The metal oxide layer can have a Vickers Hardness value of about 2000 HV. 
     Subsequently, at step  1336 , the metal oxide layer is removed and separated from the surface of the metal substrate. In particular, the metal oxide layer is exposed to a chemical stripping solution (e.g., phosphoric acid, etc.) during a self-limiting removal process that is dependent upon the metal of the metal substrate being resistant to chemical etching. The chemical stripping solution completely erodes away the metal oxide layer but does not affect (i.e., erode) the alternating peaks and valleys of the metal substrate. By removing the metal oxide layer, the alternating peaks and valleys of the metal substrate are exposed. 
     Thereafter, at step  1338 , an anodized layer can be formed over the alternating peaks and valleys. The anodized layer can impart the metal substrate with a thin-film interference color. In some examples, an optical detection system can be utilized to determine whether the anodized layer has a color that corresponds to a desired color. As a result of determining whether the color of the anodized layer matches to the desired color, then the anodization process can either continue or end. 
     At step  1340 , a portion of the anodized layer can be removed such as to expose peaks and/or valleys. The peaks and valleys can be flattened with the peaks being disproportionately reduced relative to the valleys. The flattening process can involve using a blasting or polishing process. In some examples, an optical detection system can be utilized to determine whether the color of the processed part corresponds to a desired color. As a result of determining whether the color matches to the desired color, then the flattening process can either continue or end. 
     At step  1342 , a second anodized layer can be formed to overlay the exposed peaks and/or valleys. 
       FIG. 14  illustrates an exemplary diagram of potential a* and b* values of metal parts having an anodized coating, in accordance with some embodiments. In some embodiments, the metal parts can correspond to the anodized metal part  220  and the processed anodized part  230 . 
     As described herein, the anodized metal part  220  can be formed by exposing an external surface  202  of a metal substrate  204  to a brushing process such as to form peaks  212  and valleys  214  along the external surface  202 . Thereafter, an anodized layer  224  is formed to overlay the external surface  202 . The anodized metal part  220  can have a color, using a CIE L*a*b* color space model, the surface coating has a color having an a* value between −10 to 15 and a b* value between −35 to 30. The range of color of the anodized metal part  220  is depicted as (“Brushed+Anodized”) in  FIG. 14 . In particular, the color of the anodized metal part  220  is solely dependent upon the thickness of the anodized layer  224  because the anodized layer  224  overlays the entire external surface  202  of the anodized metal part  220 . As understood by those of ordinary skill in the art, the thickness of the anodized layer  224  is proportional to the anodizing voltage.  FIG. 14  illustrates that different anodizing voltages between 5 volts to 65 volts can adjust the thickness (and therefore color) of the anodized layer  224 . However, the color of the anodized metal part  220  is limited to only colors along the lines of the color wheel depicted as (“Brushed+Anodized”) shown in  FIG. 14 . 
     In contrast, the processed anodized part  230  exhibits color variability and tunability not possible with the anodized metal part  220 . As described herein, the processed anodized part  230  can be formed by exposing the anodized metal part  220  to a mechanical finishing process (e.g., blasting, lapping, polishing, etc.). By blasting the external surface  202  of the anodized metal part  220 , different amounts of material from the peaks  212  and/or valleys  214  can be selectively removed so as to achieve more variability in color. In particular, the color of the anodized metal part  220  can be based upon the color of the exposed peaks and/or valleys as well as the color of the anodized layer  224 . In some examples, the color of the exposed peaks and/or valleys resembles natural titanium, which as depicted in  FIG. 14  has an a* value of about 0 and a b* value of about 0.  FIG. 14  illustrates the processed anodized part  230  having a color wheel (“Brushed+Anodized+Blast”) 
     For example,  FIG. 14  illustrates that forming the anodized layer  224  with an anodizing voltage of 25 volts previously limited the anodized metal part  220  to a b* value of about −35 and an a* value of about −5. However, the mechanical finishing process can selectively remove a gradient amount of the anodized layer  224 , thereby gradually shifting the color along a spoke between the color wheel (“Brushed+Anodized”) and the color wheel depicted as (“Brushed+Anodized+Blast”).  FIG. 14  illustrates that the processed anodized part  230  having an anodized layer  224  formed using an anodizing voltage of 25 volts can have a color with an a* value anywhere between −3 to 0 and a b* value anywhere between −35 to 5. 
     In another example, forming the anodized layer  224  with an anodizing voltage of 15 volts previously limited the anodized metal part  220  to a b* value of about 30 and an a* value of about 8 as shown by the color wheel (“Brushed+Anodized”). However, the mechanical finishing process can selectively remove a gradient amount of the anodized layer  224 , thereby gradually shifting the color along a spoke between the color wheel (“Brushed+Anodized”) and the color wheel depicted as (“Brushed+Anodized+Blast”).  FIG. 14  illustrates that the processed anodized part  230  having an anodized layer  224  formed using an anodizing voltage of 15 volts can have a color with an a* value anywhere between 0 to 8 and a b* value anywhere between −5 to 30. 
     Accordingly,  FIG. 14  illustrates that the processed anodized part  230  can have a color having an a* value anywhere between −10 to 15 and a b* value anywhere between −35 to 30. In other words, the color of the processed anodized part  230  is anywhere between the color wheel (“Brushed+Anodized”) and the color wheel depicted as (“Brushed+Anodized+Blast”). 
     Any ranges cited herein are inclusive. The terms “substantially”, “generally,” and “about” used herein are used to describe and account for small fluctuations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.1%. 
     The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments can also be embodied as computer readable code on a computer readable medium for controlling manufacturing operations or as computer readable code on a computer readable medium for controlling a manufacturing line. The computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, HDDs, DVDs, magnetic tape, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. 
     To the extent applicable to the present technology, gathering and use of data available from various sources can be used to improve the delivery to users of invitational content or any other content that can be of interest to them. The present disclosure contemplates that in some instances, this gathered data can include personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, TWITTER® ID&#39;s, home addresses, data or records relating to a user&#39;s health or level of fitness (e.g., vital signs measurements, medication information, exercise information), date of birth, or any other identifying or personal information. 
     The present disclosure recognizes that the use of such personal information data, in the present technology, can be used to the benefit of users. For example, the personal information data can be used to deliver targeted content that is of greater interest to the user. Accordingly, use of such personal information data enables users to calculated control of the delivered content. Further, other uses for personal information data that benefit the user are also contemplated by the present disclosure. For instance, health and fitness data can be used to provide insights into a user&#39;s general wellness, or can be used as positive feedback to individuals using technology to pursue wellness goals. 
     The present disclosure contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. Such policies should be easily accessible by users, and should be updated as the collection and/or use of data changes. Personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection/sharing should occur after receiving the informed consent of the users. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and/or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations. For instance, in the US, collection of or access to certain health data can be governed by federal and/or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA); whereas health data in other countries can be subject to other regulations and policies and should be handled accordingly. Hence different privacy practices should be maintained for different personal data types in each country. 
     Despite the foregoing, the present disclosure also contemplates examples in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and/or software elements can be provided to prevent or block access to such personal information data. For example, in the case of advertisement delivery services, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services or anytime thereafter. In another example, users can select not to provide mood-associated data for targeted content delivery services. In yet another example, users can select to limit the length of time mood-associated data is maintained or entirely prohibit the development of a baseline mood profile. In addition to providing “opt in” and “opt out” options, the present disclosure contemplates providing notifications relating to the access or use of personal information. For instance, a user may be notified upon downloading an app that their personal information data will be accessed and then reminded again just before personal information data is accessed by the app. 
     Moreover, it is the intent of the present disclosure that personal information data should be managed and handled in a way to minimize risks of unintentional or unauthorized access or use. Risk can be minimized by limiting the collection of data and deleting data once it is no longer needed. In addition, and when applicable, including in certain health related applications, data de-identification can be used to protect a user&#39;s privacy. De-identification may be facilitated, when appropriate, by removing specific identifiers (e.g., date of birth, etc.), controlling the amount or specificity of data stored (e.g., collecting location data a city level rather than at an address level), controlling how data is stored (e.g., aggregating data across users), and/or other methods. 
     Therefore, although the present disclosure broadly covers use of personal information data to implement one or more various disclosed examples, the present disclosure also contemplates that the various examples can also be implemented without the need for accessing such personal information data. That is, the various examples of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. For example, content can be selected and delivered to users by inferring preferences based on non-personal information data or a bare minimum amount of personal information, such as the content being requested by the device associated with a user, other non-personal information available to the content delivery services, or publicly available information. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the described embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20201119
Publication Date: 20221004
Grant Date: 20221004
Priority Date: 20200506
Inventors: FEINBERG, ZECHARIAH D.
CURRAN, JAMES A.
MINTZ, TODD S.
MEMAR-MAKHSOUS, JUSTIN
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "C25D11/26", "inventive": true, "first": true, "tree": "[]"}, {"code": "C25D11/26", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K5/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/26", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 78412343