Experimental Study On 3D Printed AlSi10Mg Aluminum Alloy By Selective Laser Melting

Aluminum alloy,as the most widely used nonferrous metal material in industrial manufacturing,has been studied by many scholars in the early development of metal 3D printing.Because of good comprehensive performance,Al Si10 Mg aluminum alloy parts printed by SLM process are widely used.Compared with the traditional manufacturing process,the basic mechanical properties of Al Si10 Mg aluminum alloy parts printed by SLM are better,and the model structure can be more complex.But there are also many shortcomings,such as the low printing efficiency,the poor surface quality,the low dimensional accuracy and the complicated post-processing process.Based on the above problems,the main contents of this paper are as follows:Four basic morphologies and three cross section morphologies of single-track were summarized.Effects of scanning speed,laser power and defocusing amount on the single-track geometrical morphology of Al Si10 Mg aluminum alloy were studied.The relationships between linear energy density and single-track width and height were analyzed.The results showed that the maximum single-track width was 400 ?m,the minimum single-track height was 130 ?m.The printing rate equation was established,and three groups of process parameters combinations were selected based on the layer thickness.The hardness,wear resistance,relative density,pore defects,tensile properties,dimensional deviation and surface roughness of 3D printed Al Si10 Mg aluminum alloy were analyzed,which provided the process basis for the functional requirements of parts.The influence of process parameters on surface roughness was explored.The factors that affecting the printing quality of the upper surface were analyzed,the influence law of process parameters on the upper surface roughness was studied.The combination of process parameters with the smallest surface roughness was selected,which roughness was less than 2?m.For plane overhanging structure with 30° tilt angle,the influence of process parameters on the undersurface roughness was studied.And a better combination of process parameters for the undersurface was found,which effectively avoided the existence of hanging slag and defects,the printing quality of the undersurface was also improved.The influence of process parameters on the X-direction and Y-direction printing size of Al Si10 Mg aluminum alloy was studied.The combination of process parameters was selected to ensure the accurate printing of the samples,which eliminated the uncertainty deviation caused by the direction.The theoretical value of final dimensional deviation in X-direction and Y-direction was within ±0.02 mm,which improved the dimensional accuracy.In order to predict the printing ability,the limit printing size of Al Si10 Mg aluminum alloy typical geometric features was studied,including thin plate,round hole and plane overhanging.Through model construction and experimental exploration,the design rules of typical geometric features were summarized to provide reference for actual production.