NiCrSiB合金高功率激光送粉熔覆裂纹形成的敏感因素

The Critical Influence Factors on Crack Formation During High Power CO_2 Laser Cladding of NiCrSiB Alloy by Powder Feeding

用 4 5k W高功率激光器对 Ni Cr Si B合金在送粉激光熔覆下裂纹形成的材料成分、熔覆工艺、微观组织等因素进行研究。实验表明 ,裂纹是由于熔覆层中大量的多种硬质相以及硬质相的不良分布形态所造成的高脆性 ,难以承受熔覆过程产生的较大拉应力所致。解决激光熔覆层裂纹问题的主要方向应是从工艺上降低熔覆过程的残余拉应力 ,同时从成分搭配和快速凝固特性上使得 Ni Cr Si B熔覆层微观组织中的硬质强化相细小均匀地弥散析出 。

This paper presents the extensive experimental research on the sensitive influencing factors for the crack formation during high power laser cladding of NiCrSiB alloy by powder feeding.The crack formation is mainly due to the high tensile stress induced during the process and the high brittleness of the clad formed,and the latter is due to the large amount of various hard phases in the microstructure and their undesirable configuration.The main ways to solve cracking problem should technically decreae the residual stress and at the same time make the hard strengthening phases within the clad microstructure be to precipitated in a fine and homogeneous dispersion manner.