当前位置: X-MOL 学术J. Mater. Process. Tech. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Evaluating the thermal characteristics of laser powder bed fusion
Journal of Materials Processing Technology ( IF 6.3 ) Pub Date : 2021-09-24 , DOI: 10.1016/j.jmatprotec.2021.117384
Tatsuaki Furumoto , Kazushi Oishi , Satoshi Abe , Kotaro Tsubouchi , Mitsugu Yamaguchi , Adam T. Clare

This study investigates the dynamic temperature behaviour around a melt pool in metal-based powder bed fusion using a laser beam (PBF-LB/M) to clarify the influence of the associated morphological changes of the metal powder experimentally. Gas-atomized 18Ni (300-grade) maraging steel powders were processed by PBF-LB/M while high-speed photography with a two-colour radiometric thermal imaging system that was employed to correlate the temperature with melt pool behaviour. In addition, the cooling rate of the melt pool was measured directly using the dynamic temperature distribution. The temperature distribution of the melt pool was influenced by the morphological changes of the metal powder induced by physical and thermal interactions, and the melt pool exhibited an asymmetric temperature distribution in the direction parallel to the laser scan. The significant factors were droplet cohesion at low melt pool temperatures, remaining heat energy from previous laser beam irradiation, and the heat conduction inside the melt pool. The laser beam incident on the metal powder was primarily characterized by two modes: direct heating induced by laser beam irradiation and heat conduction through the single track, droplets, and substrate. In addition, the dynamic temperature behaviour provided a direct explanation for the cooling rate, the values of which ranged from 0.1 to 0.9 × 106 K/s owing to the self-cooling induced by PBF-LB/M.



中文翻译:

评估激光粉末床融合的热特性

本研究使用激光束 (PBF-LB/M) 研究金属基粉末床熔合中熔池周围的动态温度行为,以通过实验阐明金属粉末相关形态变化的影响。气体雾化 18Ni(300 级)马氏体时效钢粉末通过 PBF-LB/M 处理,同时使用双色辐射热成像系统进行高速摄影,该系统用于将温度与熔池行为相关联。此外,熔池的冷却速度直接使用动态温度分布测量。熔池的温度分布受物理和热相互作用引起的金属粉末形态变化的影响,熔池在平行于激光扫描的方向上表现出不对称的温度分布。重要因素是低熔池温度下的液滴内聚力、先前激光束照射的剩余热能以及熔池内部的热传导。入射到金属粉末上的激光束主要具有两种模式:激光束照射引起的直接加热和通过单道、液滴和基底的热传导。此外,动态温度行为为冷却速率提供了直接解释,其值范围从 0.1 到 0.9 × 10 由激光束照射引起的直接加热和通过单个轨道、液滴和基板的热传导。此外,动态温度行为为冷却速率提供了直接解释,其值范围从 0.1 到 0.9 × 10 由激光束照射引起的直接加热和通过单个轨道、液滴和基板的热传导。此外,动态温度行为为冷却速率提供了直接解释,其值范围从 0.1 到 0.9 × 10由于 PBF-LB/M 引起的自冷却,6 K/s。

更新日期:2021-09-27
down
wechat
bug