扫描方式及激光重熔对激光选区熔化成形Inconel 718力学性能的影响

Effect of Scanning Method and Laser Remelting on Mechanical Properties of Inconel 718 by Selective Laser Melting

采用激光选区熔化技术成形Inconel 718合金,通过对抗拉强度、断后延伸率、硬度和致密度以及组织形貌的探讨,研究了扫描方式及激光重熔的工艺对Inconel 718合金力学性能的影响。结果表明,扫描方式和激光重熔对力学性能都有一定的影响。扫描方式对抗拉强度影响较大,对致密度影响较小,连续型扫描的抗拉强度最高为1059 MPa且高于铸件,不同扫描方式下的断后延伸率均高于21%;激光重熔减少了孔隙缺陷,致密度提高至99%以上,但会引发晶粒粗化和裂纹扩展,重熔前后不同扫描方式样件的抗拉强度差别都小于1%。在高温下,连续型扫描下的断后伸长率提高了15%。

The selective laser melting(SLM)was carried out to form Inconel 718 alloy. The effects of the process,including scanning method and laser remelting, on the mechanical properties of Inconel 718 alloy were investigated by examining tensile strength, elongation, hardness and relative densities as well as microstructure. The results show that both the scanning method and the laser remelting have an effect on the mechanical properties. The scanning method has a greater effect on the tensile strength and a smaller effect on the relative densities, with the highest tensile strength of 1059 MPa for continuous scanning method and higher than that of castings, and the elongation of different scanning methods is higher than21%;laser remelting reduces porosity defects and increases the relative densities to more than 99%, but causes grain coarsening and crack expansion. The difference in tensile strength between the different scanning methods before and after remelting is less than 1%. At high temperature, the elongation under continuous scanning method improves by 15%.