Influence of scanning strategies on microstructure and mechanical properties of laser powder bed fusion 2195 Al-Li alloy

Optimizing the scanning strategy is considered as an effective approach to address the challenges of laser powder bed fusion(LPBF). However, the impact of the scanning strategy on lightweight Al-Li alloys remains unclear. In this study, various scanning strategies LPBF were employed to process 2195 Al-Li alloy specimens, and a systematic investigation was conducted on the effects of the laser path on the defects, microstructure, and mechanical properties of 2195 Al-Li alloy. The results revealed that the specimens processed with the linear strategy exhibited the lowest gas pores and crack density, achieving a densification rate of 98.6 %. Furthermore, adjusting the scanning strategy led to changes in grain morphology among specimens; those processed with linear scanning demonstrated smaller average grain size (19.7 μm), a lower percentage of high-angle grain boundaries (HAGBs) (57.4 %), and a higher texture index compared to other strategies tested. When employing linear strategy for processing, tensile performance reached 315.03 MPa with 5.03 % elongation due to concise thermal history and fast cooling conditions associated with this particular scanning method. This study provides valuable insights into optimizing scanning strategies for LPBF 2195 Al-Li alloy. [Display omitted] •Linear scanning reduces heat buildup in melt pool, avoiding complex thermal history lap areas, favoring densification of LPBF Al-Li alloy.•Scanning strategy greatly altered Al-Li alloy microstructure. Simplified scanning led to finer grains and higher texture index.•Fine grains and dislocations enhance LPBF Al-Li alloy tensile properties, but metallurgical defects are the decisive factor.