Microstructure And Properties Of AlSi10Mg And AlSi10Mg/Ti6Al4V Multi-materials Prepared By Selective Laser Melting

AlSi10 Mg and Ti6Al4 V alloys have higher specific strength compared to that of other metal materials,it is widely used in the manufacture of aerospace parts.Selective laser melting(SLM)technology can integrate complex precision structural parts,it is used to form AlSi10 Mg and Ti6Al4 V alloys.The reported publications focuses on the effects of SLM process parameters and post-treatment on the properties of AlSi10 Mg alloy,the effect of powder properties on AlSi10 Mg alloy was rarely involved.The properties of powder materials,including particle size,powder morphology,powder fluidity,and chemical element content,have a large impact on the quality of the formed part.Therefore,it is particularly important and urgent to develop the effects of AlSi10 Mg powder properties on the microstructure and mechanical properties of SLM formed parts.In addition,with the aerospace demand for lightweight components,SLM forming AlSi10Mg/Ti6Al4 V multi-material is one of the future trends.This study aims to realize the properties and shape control the SLM preparation and forming of AlSi10 Mg alloy and AlSi10Mg/Ti6Al4 V multi-material.The research has mainly carried out on the influence of AlSi10 Mg powder properties on the microstructure and properties of SLM formed alloys,and the interface structure design of AlSi10Mg/Ti6 Al4 V multi-material’s phase structure,microstructure and mechanical properties.According to SLM process characteristics,the parameters of AlSi10 Mg alloy powder were optimized,the relationship between powder parameters and the microstructure,phase transition behavior and mechanical properties of AlSi10 Mg alloy was established.The influence of the interface of SLM formed AlSi10Mg/Ti6Al4 V multi-materials was studied,a method to improve the bonding strength of multi-material interfaces was proposed by the gradient interface structure.It provides theoretical guidance for the application of SLM formed multi-material parts.The results of the study found that the properties of the metal powder have a crucial impact on the quality and mechanical properties of the final formed part.The more moderate the average particle size of the powder(about 30 μm),the wider the particle size distribution,the more suitable the size and particle size,the higher the sphericity of the powder,the fewer surface planets are,the better the quality of the SLM formed part is,the fewer pore defects is.The larger the bulk density of the powder is,the better the fluidity is.Within the standard powder element content range,the smaller the Fe and Si content is,the better the tensile properties of the SLM formed part has.In addition,the interface combination of AlSi10Mg/Ti6Al4 V multi-material with trapezoidal interface structure formed by SLM has been improved,since the contact area of different alloy materials at the interface is enlarged,reduces the impact of titanium and aluminum alloys due to mismatches in thermophysical and metallurgical properties,reduces defects such as warping and cracks.The tensile properties of multiple materials(468 MPa)have been improved compared to aluminum alloy materials(416.2 MPa).