激光熔覆报废航空发动机叶片模具生成高硬度涂层的机理

The Mechanism of Generating High-Hardness Coatings on Failing Mould of Aeroengine Pieces Repaired By Laser Cladding Technology

为了研究激光熔覆高硬度涂层生成机理,采用自配的合金粉末,利用宽带熔覆技术,对4Cr5W2SiV报废模具进行了成功修复。利用OM、XRD、显微硬度计对熔覆层的组织结构及硬度进行了研究,并且对硬度的生成机理进行了分析。结果表明,模具修复效果良好,熔覆层较基材有较高的硬度。细晶强化、固溶强化、第二相强化与激光技术的快冷快热特点是生成高硬度涂层的本质原因。

To study the mechanism of generating high-hardness coatings on failing mould of aeroengine pieces repaired by laser cladding technology,the 4Cr5W2SiV failing mould were repaired by broadband laser cladding technology with self-made alloy powder.The microstructure and hardness were investigated with OM,XRD and hardness measurement,and the mechanism of generating high-hardness coatings was analyzed.The results indicate that the repair of failing mould is successful,the average hardness is much higher than that of the substrate.The key to generate high-hardness coatings is grain refinement,solid solution strengthening,the second phase strengthening and the rapid heating and rapid cooling characteristic of laser cladding technology.