Brown Ben, Newkirk Joseph, Liou Frank
Materials Engineering, Department of Energy's Kansas City National Security Campus, Kansas City, MO 64147, USA.
Material Science and Engineering Department, Missouri University of Science and Technology, Rolla, MO 65401, USA.
Materials (Basel). 2021 Jan 25;14(3):560. doi: 10.3390/ma14030560.
In the fabrication of 17-4 PH by laser powder bed fusion (L-PBF) the well-documented occurrence of large amounts of retained austenite can be attributed to an elevated concentration of nitrogen present in the material. While the effects of continuous wave (CW) laser processing on in-situ nitrogen absorption characteristics have been evaluated, power modulated pulsed wave (PW) laser processing effects have not. In this study the effects of PW L-PBF processing of 17-4 PH on nitrogen absorption, phase composition, and mechanical performance are explored using commercially available PW L-PBF equipment and compared to samples produced by CW L-PBF. PW L-PBF samples fabricated in cover gas conditions with varying amounts of nitrogen demonstrated reduced absorption levels compared to those produced by CW L-PBF with no effects on phase composition and minimal effects on mechanical performance.
在通过激光粉末床熔融（L-PBF）制造17-4 PH时，大量残余奥氏体的出现是有据可查的，这可归因于材料中氮浓度的升高。虽然已经评估了连续波（CW）激光加工对原位氮吸收特性的影响，但功率调制脉冲波（PW）激光加工的影响尚未得到评估。在本研究中，使用市售的PW L-PBF设备探索了17-4 PH的PW L-PBF加工对氮吸收、相组成和力学性能的影响，并与CW L-PBF生产的样品进行了比较。在不同氮含量的保护气体条件下制造的PW L-PBF样品与CW L-PBF生产的样品相比，吸收水平降低，对相组成没有影响，对力学性能影响最小。
