Abstract The manufacturing of 7xxx series wrought aluminum alloys using laser powder bed fusion (LPBF) is restricted due to the inherent low laser absorptivity and high crack sensitivity. In this work, Al7075 composite powders decorated with TiN nanoparticles are produced by an ultrasonic vibration dispersion technique. Results show that the laser reflectivity of the composite powders is notably reduced, leading to improved LPBF processability. Therefore, nearly dense and crack-free TiN/Al7075 composites are successfully fabricated by LPBF. The microstructure of as-built composites is significantly refined after adding TiN nanoparticles, thus inhibiting the crack initiation. The TiN/Al7075 composites exhibit remarkably improved microhardness and compressive properties compared to unreinforced Al7075 alloy. This paper provides a new path in fabricating high-strength aluminum alloys by LPBF.

中文翻译：

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具有增强机械性能的无裂纹 TiN/Al7075 复合材料的激光粉末床熔合

摘要 7xxx 系列可锻铝合金由于固有的低激光吸收率和高裂纹敏感性而受到限制。在这项工作中，用超声波振动分散技术生产了用 TiN 纳米粒子装饰的 Al7075 复合粉末。结果表明，复合粉末的激光反射率显着降低，从而提高了 LPBF 的加工性能。因此，LPBF 成功地制备了接近致密且无裂纹的 TiN/Al7075 复合材料。添加TiN纳米颗粒后，复合材料的微观结构得到显着细化，从而抑制了裂纹的产生。与未增强的 Al7075 合金相比，TiN/Al7075 复合材料的显微硬度和压缩性能显着提高。