Microstructure And Mechanical Properties Of Nano-WC Reinforced AlSi10Mg Fabricated By Selective Laser Melting

The selective laser melting technology(SLM)is the most widely used metal 3D printing technology currently,and AlSi10Mg alloy parts producted by SLM have nearly full density,and have excellent mechanical properties compared to materials produced by traditional casting processes.However,the product printing by this process have problems of lower toughness than castings or forgings,large residual tensile stress,and easily causing micro-cracks.Particle-reinforced aluminum matrix composites have the advantages of low density,high strength,low coefficient of thermal expansion,and excellent wear resistance.Therefore,the SLM process provides a new way for Particle-reinforced composites.At present.domestic and foreign scholars' research on AlSi10Mg additive manufacturing mainly focuses on the optimization of process parameters,surface treatment,and heat treatment to optimize residual stress and micro-cracks,and there are relatively few reports on the use of laser additive manufacturing nano-WC to enhance the performance of AlSi10Mg.In order to further obtain higher performance aluminum alloy composite materials,this article uses nano-WC as a nucleating agent to study two groups of samples of AlSi10Mg formulated bySLM and AlSi10Mg with nano WC added in the same process,and analyze the microstructure formation,evolution and organization.At the same time,the two groups of AlSi10Mg and WC/AlSi10Mg samples were selected to analyze the formation and evolution of microstructure and the influence of its structure on mechanical properties.Finally,in order to understand the thermal behavior of SLM parts during their processing and obtain parts with good metallurgical bonding capabilities,this paper numerically simulates the AlSi10Mg alloy formed by SLM.Due to the growth of modern industry for materials with high strength and rigidity,this project provides a new processing material and establish the foundation for particle reinforced composite materials in the field of SLM.The results show that the WC/AlSi10Mg powder has good sphericity and the particle size distribution is concentrated in 20?60 ?m.The WC/AlSi10Mg sample has a density of over 99%and a hardness of about 158.89 HV,which is 14.58%higher than that of the AlSi10Mg sample.The WC/AlSi10Mg sample grew uniformly and densely,with obvious molten pool lines.The inside of the crystal grain is ?-Al matrix,and the boundary is a eutectic Si phase interposed with WC.The yield strength of the WC/AlSi10Mg sample reaches 337.75 MPa,the ultimate strength is as high as 514.00 MPa,and the elongation is 3.78%.Compared with the same process,AlSi10Mg samples increase by 4.73%,6.25%and 35.97%,respectively.Therefore,SLM-processed WC/AlSi10Mg composite parts have better application prospects than AlSi10Mg parts.