| In this paper,the aluminum alloy powder will be molded for laser melting under certain parameters.The specific process parameters are: laser power: 200W;laser scanning speed:200mm/s;laser scanning pitch: 0.15mm;laser residence time: 80μs;Thickness: 30μm.During the forming process,because the aluminum alloy powder easily forms spheroidizing,oxidizing,sticking powder,splashing and so on,it will have some influence on the quality of the formed part.The organization and performance of the laser melting formed part in the selected area are analyzed and studied.And the effect of heat treatment on the microstructure,hardness,phase distribution,and mechanical properties of selective laser-melted parts has yielded some research results.It provides some basis for the use of aluminum alloys in industry.The main content of this article has the following points:(1)Firstly,the AlSi10Mg alloy sample was formed by selective laser melting.The microstructure,hardness,phase fraction and mechanical properties of the sample were studied.It was found that the microstructure of the AlSi10Mg alloy sample was homogeneous in the laser melting process.The grains are very small.Selective laser melting AlSi10Mg alloys exist two strengthening mechanisms,one is that Si phase exists in the Al matrix in the form of a solid solution,showing a solid solution strengthening mechanism,the other is the formation of fine grain microstructure,showing fine grain Strengthening mechanism,so its strength and hardness is much higher than the traditional casting,the selective laser melting AlSi10Mg alloy specimen tensile strength and yield strength up to 456 ± 10 MPa and 270 ± 10 MPa,respectively,compared with the same material casting standards,respectively,about 52%higher And about 58.9%,the elongation is 4.5%,slightly higher than the casting standard.(2)Secondly,the effect of annealing heat treatment process on the microstructure,hardness,phase distribution and mechanical properties of the laser-melted Al Si10 Mg alloy samples was analyzed.The specific process is: Incubate at 220°C,260°C,300°C for 2 hours,and cool down to room temperature with the furnace.It is found that as the annealing temperature increases,the supersaturated Si gradually precipitates in the Al matrix,and the precipitated Si gradually aggregates and grows.The strength and hardness of the alloy sample continuously decrease,and the elongation rate increases continuously.When the annealing temperature is 300°C,the average size of the fracture sag can reach 3μm.The tensile specimen has a relatively high ductility.Its tensile strength and yield strength are 360±5MPa and 240±5MPa,respectively,while the elongation reaches 9 %,the elongation increased to about 2 times that of the untreated sample.(3)Finally,the effect of solution heat treatment and aging on the microstructure,hardness,phase distribution and mechanical properties of AlSi10Mg alloy samples was analyzed.The specific process is: Incubate at 450 °C for 2h,4h,6h;500 °C for 2h,4h,6h;550 °C for 2h,4h,6h.It was found that at the same temperature,the tensile strength and yield strength of the specimen decreased as the holding time lengthened.The hardness shows a gradual decline and tends to be gentle,but its elongation becomes large.At the same holding time(2h),as the solution temperature increases,the equiaxed depression of the tensile specimens increase in size.When the solution temperature is 550°C,the size of the equiaxed depressions reaches 5μm.The ultimate tensile strength and yield strength of the specimens continuously decreased,and the elongation gradually increased.After the solution heat treatment(450°C for 2 hours,500°C for 2 hours,and 550°C for 2 hours),the sample was completely artificially aged(180°C for 12 hours)while the furnace was cooled to room temperature.The strength has a downward trend compared with the solution treatment at the same temperature,and the elongation rate is still larger. |
