Abstract Laser cladding is an additive manufacturing process which is spreading as a valuable resource for manufacturing and repairing mechanical components that are subjected to intense wear. Advantages over conventional welding include a much lower heat input and minimal dilution, also surpassing metal spraying due to the resulting metallurgical bond. In this paper, the effect of laser cladding on the fatigue life of a 70 mm diameter component of wrought quenched and tempered AISI-SAE 4140H is assessed, along with full characterization of defects, hardness and residual stress distributions. Additionally, a theoretical fatigue crack propagation prediction model based on a fracture mechanics approach is demonstrated to provide acceptable estimated fatigue lives, and shows how the most influential process variables affect these results.

中文翻译：

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激光增材制造修复钢构件的疲劳寿命

摘要 激光熔覆是一种增材制造工艺，作为制造和修复承受剧烈磨损的机械部件的宝贵资源正在传播。与传统焊接相比的优势包括低得多的热输入和最小的稀释，由于产生的冶金结合也超过了金属喷涂。在本文中，评估了激光熔覆对锻造调质 AISI-SAE 4140H 的 70 毫米直径部件疲劳寿命的影响，以及缺陷、硬度和残余应力分布的完整表征。此外，证明了基于断裂力学方法的理论疲劳裂纹扩展预测模型可以提供可接受的估计疲劳寿命，并显示最有影响的过程变量如何影响这些结果。