工艺参数对镍基合金粉末激光快速烧结成形的影响

Effects of Processing Parameters on Forming of Nickel -Based Alloy Powders by Laser Engineered Net Shaping

激光近形制造技术（1aser engineered net shaping，LENS）是一种低成本、快速制作高性能全致密金属零件的技术。采用不同的激光烧结参数研究了镍基合金的激光快速烧结成形。利用显微硬度分析和金相分析研究了扫描速度、激光功率、离焦量、送粉气流量对薄壁组织及性能的影响。微观组织观察表明，成形件组织致密，发育有枝状晶体等快速凝固组织所具有的特征。制件的平均显微硬度（HV）在1．35～1．90 GPa之间。通过实验得到了一组优化的工艺参数，并由此烧结出了结构致密、显微硬度较高的薄壁器件。

Laser engineered net shaping （LENS）, as one of the branches in rapid prototyping techniques, may directly shape metal functional components which have reasonably complicated shapes and structures. In this paper, the effects of processing parameters, such as scaning speed, laser power, focus displacement, and gas feed rate on the shaping of Ni-14.4Cu-1.6Sn powders by LENS were invesgated The microstructures of the shaped thin-wall specimens were observed. Rapid cooling and qucik densification microstructures such as dendritic structures marked the as-deposited thin-wall parts. The averaged microhardness（HV） of the parts is between 1.35 GPa to 1.90 GPa. The optimized processing parameters were obtained in this case. Thin-wall parts with good properties were fabricated successfully by LENS with optimized processing parameters.