| Titanium alloy materials have been widely used in the field of artificial bone manufacturing due to their excellent corrosion resistance,mechanical properties and easy processing properties.However,due to the shortcomings of inertness and poor wear resistance on the surface of the titanium alloy,the artificial bone has the problems of slow bonding speed and serious wear after implantation in the human body,resulting in inflammation around the artificial bone,and even the symptoms of artificial bone falling off.In order to improve the performance of titanium alloy artificial bone,it is the key problem of current research to solve the poor bonding ability and poor wear resistance of titanium alloy artificial bone.The preparation of micro and nano structures on the surface of titanium alloy artificial bone is beneficial to improve the biocompatibility and wear resistance of titanium alloy surface.In this thesis,the surface of titanium alloy was designed and fabricated with micro-nano structure,and study friction performance and biocompatibility research.Firstly,the surface texture of titanium alloy artificial bone was designed based on bionics theory.Based on the analysis of the natural bone surface structure and the skin morphology of the tree frog's soles and feet,combined with the influence of the micro-nano size on the behavior of bone cells,four types of surface micro-nano composite structures with a combination of circular and regular hexagons were designed and the texture parameters were determined.Then,this thesis studies the construction method of micro-nano composite on the surface of titanium alloy.Using laser ablation method to prepare surface micron-level convex texture,analyze the surface morphology of titanium alloy under different processing parameters,and finally determine the optimal parameters: processing speed 300mm/s,power 20 W,frequency30KHZ.On this basis,the relationship between the number of processing and the height of texture is studied.The multiple acid etching method is used to prepare nano-scale holes on the surface of the titanium alloy,and at the same time,the problem of the slag left by the laser ablation on the surface of the titanium alloy is solved.Secondly,this thesis uses friction and wear experiments to study the antifriction effect of the micro-nano structure on the surface of titanium alloys with different shapes,side lengths and heights.Firstly,the effects of texture of different shape,side length and height on the average friction coefficient were analyzed.Then,the interaction of shape,side length and height on the average friction coefficient was studied.Response surface fitting and optimization analysis were carried out by Box-Benhken module in Design Expert to obtain the minimum average friction coefficient.In the end,the smallest average friction coefficient is 0.0902,and the corresponding characteristic value is: the shape is 0.66(circle surrounds the regular hexagonal array pattern),the height is 200?m,and the height is 60?m.Thirdly,this thesis uses contact angle experiments to study the wettability of micro-nano composite structures on different surfaces.By measuring the contact angle value of the textured surface of different shapes,side lengths and heights,the influence of the shape,side length and height on the contact angle value of the surface texture is analyzed.The full-factor experiment is used to analyze the interactive influence of shape and side length on the contact angle,and the interactive surface is fitted by the fit function in MATLAB to obtain the smallest surface contact angle.Finally,this thesis uses simulated body fluid immersion experiments to study the biological activity of different surface micro-nano composite structures.The effects of different shapes,side lengths and heights on the deposition of hydroxyapatite on the surface texture of titanium alloys were analyzed,and the growth mechanism of hydroxyapatite in simulated body fluids was analyzed. |
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