Patent ID: 12247956

In the drawings,100: three-dimensional electric positioning module,200: imaging module,300: dot matrix impact indentation module,400: clamp, and500: test piece;

110: XY translation stage,120: Z-axis lifting stage,111: servo motor,112: fine grinding lead screw,113: cross guide rail, and114: grating ruler;

210: microscope lens,220: mounting rib plate,230: sliding block, and240: light source;

310: three-degree-of-freedom piezoelectric platform,320: piezoelectric ceramic actuator,330: annular support,340: opposite-top wedge block,350: laser Doppler seismometer,360: reflective silicon wafer,370: micro-force sensor,311: piezoelectric stack,312: bionic mantis claw,313: guide rail,321: pressing rod,322: indenter,331: fastening bolt, and332: bearing; and410: movable platform.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The specific implementations of the present invention will be described clearly and completely below with reference to examples and drawings. It is clear that the described embodiments are merely a part rather than all of embodiments of the present invention.

As shown inFIGS.1to5, a rapid dot matrix micro-nano impact indentation testing system comprises:a three-dimensional electric positioning module100, wherein the three-dimensional electric positioning module100comprises an XY translation stage110and a Z-axis lifting stage120, and the Z-axis lifting stage120is arranged on the XY translation stage110.

Specifically, as shown inFIGS.1and2, the three-dimensional electric positioning module100mainly functions to initially position a dot matrix impact indentation module300. When the dot matrix impact indentation test is performed, an indenter322needs to be aligned to a to-be-tested material, and after one impact is completed, the position of the indentation test needs to be immediately replaced to perform the impact indentation test again.

To make the positioning more accurate, in this embodiment, the three-dimensional electric positioning module100is provided as the XY translation stage110and the Z-axis lifting stage120, and the Z-axis lifting stage120is arranged on the XY translation stage110, and the Z-axis lifting stage120can move in a horizontal direction on the XY translation stage110. Meanwhile, the dot matrix impact indentation module300is arranged on the Z-axis lifting stage120, and the movement of the dot matrix impact indentation module300in a vertical direction can be achieved through the Z-axis lifting stage120.

To make the displacement more accurate, in this embodiment, a power for the XY translation stage110is a group of servo motors111arranged orthogonally, an output end of the servo motor111is connected to a fine grinding lead screw112, one end of the fine grinding lead screw112is connected to a cross guide rail113, the cross guide rail113drives the Z-axis lifting stage120to translate, and the arranged fine grinding lead screw112makes the displacement more accurate. Meanwhile, three identical grating rulers114are arranged on a side surface of the cross guide rail113and a side surface of the Z-axis lifting stage120. The grating rulers114monitor and control the displacement in the X direction, Y direction and Z direction, so that the displacement of the dot matrix impact indentation module300can be accurately controlled, making the final impact test position more precise.

The rapid dot matrix micro-nano impact indentation testing system further comprises a dot matrix impact indentation module300, wherein the dot matrix impact indentation module300comprises a three-degree-of-freedom piezoelectric platform310arranged on the Z-axis lifting stage120, one surface of the three-degree-of-freedom piezoelectric platform310is provided with a piezoelectric ceramic actuator320, and one end of the piezoelectric ceramic actuator320is connected to an indenter322through a pressing rod321; a piezoelectric stack311and a bionic mantis claw312with an arc-shaped tail end are arranged in the three-degree-of-freedom piezoelectric platform310, and the bionic mantis claw312amplifies a stroke of the piezoelectric stack311based on a lever principle.

As shown inFIGS.1,4, and5, in this embodiment, the dot matrix impact indentation module300mainly comprises a three-degree-of-freedom piezoelectric platform310and a piezoelectric ceramic actuator320, wherein the three-degree-of-freedom piezoelectric platform310can further adjust the position of the indenter322on a microscale, so that the impact test position is more accurate. The piezoelectric ceramic actuator320is the primary component for impact testing.

In this embodiment, the difference between the three-degree-of-freedom piezoelectric platform310and a conventional piezoelectric platform is that the conventional piezoelectric platform simply adopts a combination of a piezoelectric stack and a flexible hinge to drive a moving guide rail of the piezoelectric platform, so that the piezoelectric platform can perform a tiny displacement and adjust the position of the piezoelectric ceramic actuator320at a microscopic level. However, the conventional three-degree-of-freedom piezoelectric platform310is poor in motion stability. To solve this problem, the inventors find from a large number of experiments that the flexible hinge is configured as a bionic mantis claw312with an arc-shaped tail end, the tail end of the bionic mantis claw312is in contact with the guide rail313, deformation of the piezoelectric stack311is transmitted to the guide rail313of the three-degree-of-freedom piezoelectric platform310through the bionic mantis claw312, so that the three-degree-of-freedom piezoelectric platform313generates displacement in three directions. Meanwhile, the arc-shaped tail end of the bionic mantis claw312will ensure that the contact force gradually increases during the slow adhesion process, which helps drive stability; and this also facilitates rapid separation of the jaws with a decreasing contact force during the reverse sliding movement. It has been verified experimentally that the bionic mantis claw312can exert the stick-slip concept to the utmost extent, and effectively inhibit rollback due to the fact that 95.5% of effective stroke is obtained. The effective stroke of a conventional lever-type flexible hinge is about 80%, so that compared with the conventional flexible hinge, the bionic mantis claw has a better effect.

To make the movement of the piezoelectric ceramic actuator320more accurate, in this embodiment, an annular support330is further provided outside the piezoelectric ceramic actuator320, and the piezoelectric ceramic actuator320is fixedly arranged inside the annular support330. A main body of the piezoelectric ceramic actuator320is arranged inside the annular support330, an output end of the piezoelectric ceramic actuator320is provided with a pressing rod321, the other end of the pressing rod321is connected to an indenter322, the displacement and the impact force generated by the piezoelectric ceramic actuator320are transmitted to the indenter322through the pressing rod321, and the impact indentation test is performed on a test piece500through the indenter322. To ensure the stability between the pressing rod321and the indenter322, a bearing332is provided at one end of the annular support330, and the pressing rod321passes through the bearing332and is arranged outside the annular support330.

According to the research of the inventors, since this embodiment adopts the mode of direct impact of the piezoelectric ceramic actuator320, the stroke of the piezoelectric ceramic actuator can reach more than 100 micrometers, and the basic requirement of micro-nano impact can be met. Meanwhile, compared with the prior art, the piezoelectric ceramic actuator320of the present invention is short in response time and high in impact speed, and can achieve impact under high strain conditions (102-104/s).

The annular support330can be configured as a single annular support330, or may be provided as an annular support330composed of a plurality of parts. In this embodiment, to ensure the stability of the pressing rod321, an inner ring and an outer ring are provided, the outer ring is provided with an opening, the piezoelectric ceramic actuator320and the opposite-top wedge blocks340are all arranged inside the inner ring, and a main body of the inner ring is arranged inside the outer ring. Meanwhile, one end of the pressing rod321passes through one side wall of the inner ring and one side wall of the outer ring and is arranged outside the outer ring, and the bearing332is arranged on the outer ring. According to the present invention, the inner ring and the outer ring are arranged, so that the stability of the pressing rod321is higher.

Conventionally, a tail portion (one end far away from the pressing rod321) of the piezoelectric ceramic actuator320and the annular support330are difficult to completely fit. When the piezoelectric ceramic actuator320moves, a part of displacement generated by the piezoelectric ceramic actuator can be used to overcome a gap between the tail portion of the piezoelectric ceramic actuator320and the annular support330, resulting in the actual displacement distance and the impact strength of the piezoelectric ceramic actuator320being less than a theoretical displacement distance and a theoretical impact strength, which further leads to distortion of the impact indentation test results. To solve the above problem, the inventors pre-tighten the piezoelectric ceramic actuator320by providing opposite-top wedge blocks340.

Specifically, the opposite-top wedge blocks340are a pair of top blocks with a main body shape of a right triangle, and the two oblique sides thereof are fitted together. Meanwhile, a fastening bolt331is arranged on at least one side wall of the annular support330, the fastening bolt331penetrates through the side wall of the annular support330, and one end of the fastening bolt331arranged inside the annular support330is in contact with the side edges of the opposite-top wedge blocks340. Before the piezoelectric ceramic actuator320is used, a transverse force is applied to the opposite-top wedge blocks340by screwing the fastening bolt331, then two top blocks of the opposite-top wedge blocks tend to displace, and the transverse force is converted into a longitudinal pre-tightening force for the piezoelectric ceramic actuator320, so that the pre-tightening for the piezoelectric ceramic actuator320is completed, and the impact indentation experiment results are more accurate.

To facilitate real-time monitoring of the force and displacement in the impact indentation process, a laser Doppler seismometer350is provided at an upper part of the dot matrix impact indentation module300, and a reflective silicon wafer360matched with the laser Doppler seismometer350is arranged at one end of the pressing rod321close to the indenter322. The force in the impact indentation process is monitored in real time through a micro-force sensor370, and the displacement and the micro vibration in the impact indentation process can be monitored through the laser Doppler seismometer350and the reflective silicon wafer360.

The rapid dot matrix micro-nano impact indentation testing system further comprises a clamp400, wherein the clamp400clamps a test piece500, and the test piece500faces the indenter322.

As shown inFIG.1, the clamp400mainly functions to clamp the test piece500. Theoretically, any clamp400capable of clamping the test piece500and providing a certain support can be applied to the present invention. However, in practical use, the inventors find that the effect of clamping the test piece500by using a pneumatic clamp is better, the pneumatic clamp is convenient to clamp, does not need to be screwed by hands, and can achieve automatic control.

In this embodiment, to facilitate the operation of the technician, the clamp body of the pneumatic clamp is arranged on a movable platform410, and the movable platform410can be driven by a motor, so as to achieve the up-and-down movement of the pneumatic clamp.

The rapid dot matrix micro-nano impact indentation testing system further comprises an imaging module200, wherein the imaging module200comprises a microscope lens210, and the microscope lens210is configured to observe and photograph the test piece500.

As shown inFIGS.1and3, in this embodiment, the microscope lens210is a metallographic microscope lens. To facilitate observation of the test piece500, a mounting rib plate220is fixedly provided on one side of the Z-axis lifting stage120, a sliding block230is arranged on the mounting rib plate220, and then the microscope lens210is arranged on the sliding block230. This arrangement enables the microscope lens210to move. For the microscope lens210, a certain light source is usually required in the observation process, and therefore, in this embodiment, a light source240is further provided on the sliding block230, and the light source240can cooperate with the microscope lens210to observe the test piece500.

When in use, the test piece500is clamped and fixed by the clamp400, the piezoelectric ceramic actuator320is pre-tightened by the opposite-top wedge blocks340, the microscope lens210is moved to the front of the sample through the three-dimensional electric positioning module100and the sliding block220(in this case, the indenter322has moved to the front of the test piece500), and the light source240is turned on to make the lens image. By observing the metallographic structure on the surface of the test piece500, the test area is accurately selected.

Then, the indenter322is moved to the selected area to be tested through the precise control of the three-degree-of-freedom piezoelectric platform310, the piezoelectric ceramic actuator320is powered, the piezoelectric ceramic actuator320drives the indenter322to perform impact indentation. After a single impact indentation is completed, the three-degree-of-freedom platform310achieves dot matrix positioning with nanometer-level positioning accuracy, and achieves matrix-type impact by performing multiple indentations. Meanwhile, the structural changes of the material surface during the indentation process are obtained through the microscope lens210, and the displacement and impact force during the pressing process are monitored based on the laser Doppler seismometer350and the micro-force sensor370.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the preferred embodiments above have disclosed the present invention, they are not intended to limit the present invention. Any of those familiar with the technical field, without departing from the scope of the technical solutions of the present invention, can use the technical content disclosed above to make various changes and modify the technical content as equivalent changes of the equivalent embodiments. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical spirit of the present invention without departing from the content of the technical solutions of the present invention shall fall within the scope of the technical solutions of the present invention.