Laser Surface Modification Of Ceramic Tools Based On Wettability Mechanism

The rapid wear and tear of ceramic tools restricts the development of the manufacturing industry.The high performance surface micro texture can improve the wear performance of the ceramic tool.Based on the Wettability Mechanism of the solid surface,it is also a feasible method to study the relationship between the wettability of the ceramic tool surface and the texture surface structure to reduce the wear and tear of the tool.Therefore,in view of the influence of laser processing parameters on the micro texture of ceramic tool surface and the influence of surface microtexture on the wetting properties of ceramic tools,the two core problems are studied in this paper.The specific work is as follows:First,the damage threshold of ceramic tool materials processed by femtosecond laser is studied,which provides a reference for the subsequent laser processing.Then,we use different laser parameters to process ceramic tool materials,study the influence rule of laser processing parameters on the surface microstructure,further optimize the parameters according to these rules,process the required surface microstructure,and then do the wettability test.The influence of the disordered structure,the pits structure and the groove structure on the wettability of the surface was studied.The experimental results show that:(1)there exists an exponential relationship between the contact angle and surface wetting speed of ceramic materials after laser treatment,the contact angle can be used to represent the wetting speed,provides a new method to measure the water based cutting fluid wettability of ceramic tools.The disordered tool surface prepared by using higher spot coincidence degree and larger monopulse energy has better hydrophilicity.(2)the circular concave pit structure and the groove structure surface obtained by laser processing,its wettability law conforms to the Wenzel model.After heat preservation,the surface stress of the material will be reduced,thus reducing the surface energy and increasing the contact angle.For the circular pit structure,area ratio in the range of 15%~30%,aspect ratio constant,surface texture area rate is large,the surface more hydrophilic area;rate constant,improve the aspect ratio of can reduce the surface contact angle.The area occupancy of the concave pit is about 15%,and the surface of the Sialon ceramic tool has good wettability when the depth is more than 20?m.(3)for the groove structure,and the groove center distance is 100?m,the change of contact angle with groove width is not obvious;the groove width is 38?m,the depth of the groove is 12?m,the convex platform width changes from 30?m to 100?m,the contact angle gradually increased;groove pitch is 100?m,the depth of the trench changes from 5?m to 30?m,the contact angle decreases gradually.The results show that the better groove structure should be less than 30?m,the distance should be about 70?m,and the depth of the groove should be higher than 20?m.