Multiple Factors Comprehensive Impact Model Establishment And Experimental Study On Mechanical Properties Of SLM Parts

Selective Laser Melting(SLM),which has a wide range of applications in aerospace,biomedical science and other fields,is one of the most promising technologies in Additive Manufacturing.However,there are many factors that affect the properties of SLM molded parts,making different properties of the mechanical molded parts.In order to improve the properties of SLM molding parts,it is of great theoretical significance and practical value to optimize the parameters and improve the properties of parts by studying the influence rules of various parameters on the properties of SLM parts.Therefore,this paper explores the influence of various parameters on the mechanical properties of 316 L SLM molded parts,and builds a mathematical model of the comprehensive influence of various parameters on the mechanical properties of SLM molded parts.The main research contents of this paper are as follows:(1)Single-factor experiments are used to explore the effect of laser scanning angle on the mechanical properties of SLM molded parts.The SLM parts are formed at the same angle for each layer and the specific angle rotated by each layer respectively,based on which the tensile strength,elongation,density and hardness are tested,and microscopic morphology and fracture morphology are analyzed.By summarizing the influence rule of laser scanning angles on the mechanical properties of parts,the optimal laser scanning angle is determined.(2)Single-factor experiments are used to explore the effects of laser power,scanning speed and hatch space on the mechanical properties of SLM molded parts.Through the test of tensile strength,elongation,density and hardness,as well as the observation and analysis of the micro-morphology and fracture morphology of the parts,the effect of process parameters on the mechanical properties of the parts is summarized,the optimal process parameters are also determined.(3)Based on the results of single-factor experiments,the horizontal parameters range of the laser power,scanning speed and hatch space in the orthogonal test are selected to explore the comprehensive effects of the process parameters on the mechanical propertiesof the parts.By analyzing the results of the extreme in the orthogonal test,the main factors affecting the mechanical properties of the parts in the process parameters are determined,and the combination of the best process parameters is found.(4)Based on the response surface methodology,a mathematical model affected by the combination of laser power,scanning speed and hatch space on the tensile strength of SLM molded parts is constructed.The experimental verification shows that the mathematical model is able to greatly represent the regularity of the mechanical properties changing with the process parameters within a specific range,which provides a theoretical basis for the optimization of process parameters.