Micro-porosity and Tensile Property of High Relative Density Inconel 718 Superalloy Fabricated by Selective Laser Melting [高致密度激光选区熔化Inconel 718合金中的微小孔隙缺陷和拉伸性能]

作者：Liu F.; Hu W.; Jia J.; Liu F.; Xu Y.; Wang Z.

来源：Rare Metal Materials and Engineering, 2021, 50(10): 3684-3692.

• Inconel 718 superalloy
• Laser selective melting
• Micro-porosity
• Tensile property

Inconel 718 alloy samples with different relative densities were prepared by selective laser melting technology. The influence of processing parameters including laser power and scanning speed on the relative density of alloy samples was studied. The formation causes of micro pore defects and its effect on the tensile property were analyzed. The mechanical properties of alloys with different relative densities by SIDA heat treatment were studied. The results show that the interaction mode between laser and powder is determined by processing parameters. The "key-hole" mode occurs under the condition of high laser power and low scanning speed, which results in more pores and the decrease of density. When the power decreases or the scanning speed increases, the "key-hole" mode would change to the "heat conduction" mode, and the pores would decrease, the relative density would increase. However, when the laser power is too small or the scanning speed is too large, the unfused pore defects would occur, which would greatly reduce the relative density of the sample. Tensile test results show that the strength of the selective laser melted Inconel 718 alloy sample does not increase in a strictly monotonic manner with increasing the relative density. The morphology, quantity and size of the micro pore defects also has an effect on the tensile properties of the samples. In addition, SIDA heat treatment can greatly improve the microhardness and tensile strength of selective laser melting formed Inconel 718 alloy, but the plasticity significantly reduces.

• 单位
  南昌航空大学