大功率激光熔化镍基高温合金成形实验研究

Experimental study on nickel-based superalloy formation based on high-power laser melting process

为研究大功率激光下镍基高温合金IN718成形工艺参数对其表面质量及致密度的影响,采用DYLM-200金属粉末熔化成形机制做八个试样,通过扫描电子显微镜观察其表面形貌,分析不同激光工艺参数下试样的表面形貌特征。实验结果表明:成形工艺参数的改变直接影响成形零件的表面质量及其致密度。较小激光能量密度产生的球化现象减小了成形零件的致密度,适当地增加激光能量密度可以获得较好的成形表面质量和零件致密度;适当地减小激光扫描间距可以减少孔隙的产生,能够提高零件的致密度。该研究为选择性激光熔化3D打印成形的IN718零件在航空航天中的应用以及后续的研究提供了参考依据。

This paper is an attempt to study the mechanism underlying the influence on the surface quality and densification of process parameters related to Nickel-based superalloy IN718 samples fabricated by using high-power laser. This study involves fabricating eight Nickel-based superalloy IN718 samples using DYLM-200 metal powder melt molding machine, examining the formation of the samples by scanning electron microscope, and thereby defining the surface morphology in various process parameters. The experimental results show that a change in the laser process parameters has a direct effect on the sur- face quality and density of molding parts; the bailing effect resulting from a relatively lower laser energy density leads to a reduction in the density of molding parts and consequently, an appropriate increase in the laser energy density enables a better surface quality and density of molding parts; and a proper decrease in the laser scan spacing allows a fewer pores and a better density of molding parts. The study may provide a reference for the aerospace application of IN718 parts produced by selective laser melting for 3D printing and the subsequent research.