Study On Properties Of Metal-matrix Composite Materials Prepared By Laser Assisted Electro-deposition

The rapid development of aerospace and electronics promotes the research and application of Metal Matrix Composites.Various ways to fabricate metal matrix composites have also emerged.Deposition technology has the advantages of simple device,can be carried out at room temperature,lower cost and other advantages.Therefore,the preparation of metal matrix composites by electro-deposition has great research value for the preparation of new materials.However,in conventional composite electro-deposition technique,nanoparticles tend to attract each other and self-sedimentation will lead to poor deposition quality,slow processing speed and other defects,which constrain the development and application of this technology.The technique of using laser-generated thermal effect to promote the composite electro-deposition process is called laser-assisted nano-composite electro-deposition technology.This method can effectively improve the rate of electro-deposition processing,alleviate the aggregation of particles,and improve the processing quality of composite deposition layers.Traditionally,ultrasonic,magnetic fields and mechanical agitation have been introduced during the electro-deposition process.These effects are concentrated on the entire composite deposition fluid,while the role in the processing area is still not particularly obvious.Due to the small laser spot diameter,it can cause micro-area flow field in the processing area.In order to fully study the law of laser action,the mechanism of laser action is analyzed.The finite element simulation is carried out.A laser assisted nano composite electro deposition platform is set up.The effect of laser irradiation on the process of composite deposition,deposition quality and deposition layer performance is analyzed respectively.The main research contents are as follows:1.The basic principle of laser assisted nano-composite electro-deposition was investigated.The basic theory of composite electro-deposition was analyzed which includes liquid phase mass transfer,electric field action,grain generation and growth and composite electro-deposition model.The effects of laser irradiation on the mechanical impact of the processing zone,especially the plasma shock wave and cavitation on the localized flow field were discussed.The dispersing effect of the flow field on the nanoparticles was also analyzed.Finally,the laser effects including thermal effects,strong agitation,and stress shock on the deposition process and the quality of the deposited layer were analyzed.2.According to the mechanism of laser irradiation,a laser thermal and mechanical interaction model was established.Finite element simulation of irradiation zone temperature and flow rate was carried out.In addition,the deposition rate of laser and the impact stress of the machining zone were also analyzed.A laser-assisted nano-composite electro-deposition test system was constructed,including laser irradiation systems,electro-deposition systems,motion control systems,etc.3.The experiment of laser assisted nano-composite electro-deposition was carried out.A probe-type hydrophone was used to study the inhibitory effect of nanoparticles on the laser,and the suitable laser parameters and particle content was chosen according to the test result.The influence of laser irradiation on the rate of composite deposition was analyzed.The influence of laser irradiation on the grain,element species,surface morphology and cross-sectional morphology of the composite deposition layer was researched.The effect of laser on corrosion resistance of composite deposits was studied.Finally,the effect of laser on the micro-hardness of the coating was analyzed.By analyzing the mechanism of laser-assisted nano-composite electro-deposition,combined with the experimental process and results,the following conclusions can be draw: The thermal utility of laser irradiation can significantly promote the liquid phase mass transfer process,improve the rate of electrochemical reaction,improve the quality of composite deposition,and refine the grain of the coating;Meanwhile,the shock wave induced by the laser plasma and the impact force of the cavitation jet can help to disperse the nanoparticles and fill the grain boundary cavity.Therefore,the composite layer with better cross section morphology can be obtained,thus the laser irradiation can effectively improve the corrosion resistance and micro-hardness of the composite layer.