Study On Technology Of Aluminium Alloy/Ceramic Gradient Material By Laser Deposition

Aluminum alloy has been widely used in various industrial fields because of its light weight and good corrosion resistance.However,poor hardness and poor wear resistance have been a shortage of aluminum alloy.The whole or surface strengthening of aluminum alloy is an effective way to solve this problem.In this paper,the oxide ceramic powder?CaO-B2O3-SiO2?was deposited on the surface of 2024 aluminum alloy by laser deposition technology.The aluminum alloy/oxide ceramic gradient composite material was prepared by in-situ Al₂O₃ ceramic particle reinforced phase.The reasonable deposition process parameters were established by laser single channel deposition experiment.OM,SEM,EDS and XRD were used to study the microstructure of the gradient material layer under states of deposition state,solid solution aging and homogenization treatment.The friction and wear properties and microhardness of each graded layer was tested,and the gradient of the wear mechanism and strengthening mechanism were studied.Finally,the bonding strength of the gradient material was tested and analyzed.The research shows that the reasonable process parameters,the substrate is well bonded to the ceramic gradient layer without defects,gradient material layer grains gradually finer with the increase of the gradient ratio.Gradient layer includes a-Al,Al₂Cu,Al₂CuMg,SiO₂,Al₂O₃ phase,the in-situ Al₂O₃ particles is distributed in the gradient material,and with the increasing of the ceramic content,the number of Al₂O₃ particles increases.The hardness of the gradient material increases with the increase of the gradient ratio in the three states.The friction coefficient of the gradient material is lower than that of the substrate,and the wear weight loss is far less than the substrate,which shows better wear resistance.The wear resistance of the deposited and homogenized gradient materials increases with the increase of the gradient ratio,The wear resistance of the solid solution aging gradient material decreases with the increase of the gradient ratio.When the oxide ceramic is deposited on the aluminum alloy,the bonding strength of gradient transition method is better than the direct transitio.