Research On Optimization Of Slm Forming Process And Soot Suppression Of AZ91D Magnesium Alloy

Magnesium alloys are widely used due to their advantages of light weight,high specific strength,abundant reserves and good biocompatibility.AZ91 D magnesium alloy is a widely used alloy material.However,in the selective laser melting forming process,the parts are not dense and the soot problem is prominent.Therefore,further research on its forming process is needed to obtain large-size parts high density,less soot,and good mechanical properties.In this paper,the selective laser melting of magnesium alloy was studied from the aspects of process parameters,powder size and equipment.The main contents are as follows: Firstly,high-density magnesium alloy parts are made through the design of process parameters.Then,under the condition of the parameter,the particle size range of the part with good mechanical properties can be obtained while reducing the generation of soot by changing the powder particle size;The circulation path of protective gas is adjusted by ANSYS simulation method to improve the removal effect of soot.Finally,through the forming experiment of the basic structure of magnesium alloy,large magnesium alloy parts were prepared.Conclusion: 1)Under the parameters of 90 W,40 μm point distance(scanning speed400 mm/s)and 40 μm scanning distance,the density of formed magnesium alloy parts can reach 99.80%.Under different scanning speed,there is a suitable point distance.2)The results show that the magnesium alloy powder with the particle size of 30-60 μm and large particle size in large proportion produces less soot in the forming process,and the tensile strength reaches 330 MPa.Through the simulation analysis,it is concluded that the soot removal effect is significantly improved by adopting the double circulation path of two horizontal stacked long holes in the air inlet and two upper and lower air outlets.3)The minimum forming data of magnesium alloy foundation structure parts are obtained by experiments.Based on this,magnesium alloy parts with height of 100-200 mm are successfully made.