针对TC4合金叶片经常性表层裂纹萌生、体积损伤以及修复材料成本高的工程实际, 优选FeCrNiB系以及TiAlVFe系合金材料, 基于脉冲激光成形工艺优势, 实现了TC4合金叶片表层裂纹及体积损伤修复, 从成形工艺、金相组织、显微硬度以及三维尺寸等方面验证了工艺匹配性。结果表明: FeCrNiB合金熔覆层主要由细小致密的等轴晶、交错分布的树枝晶以及均匀分布的胞状晶组成, 而TC4合金主要由针状马氏体和网篮组织交错伴生组成, 都具有较好的组织形态。FeCrNiB合金熔覆层显微硬度为380~750 HV0.1, 较基体提升约1倍; TC4合金熔覆层显微硬度为295~350 HV0.1, 与基体基本保持一致。叶片成形后整体形状尺寸精度控制在0.8 mm以下。通过激光工艺优化和性能匹配分析可知, FeCrNiB合金适合局部微裂纹修复, 而TC4合金适合体积损伤成形。

Aiming at the frequent surface crack, volume damage and high cost of repairing materials for TC4 alloy blades, the FeCrNiB alloy and TiAlVFe were chosen for remanufacture, the surface cracks and volume damage of TC4 blade were remanufactured based on the advantages of pulsed laser forming process, the process matching was verified from the forming process, the metallographic microstructure and three-dimensional size aspects. The results show that the FeCrNiB cladding layer is composed of fine and compact equiaxed crystals, interlaced dendrite and homogeneously distributed cell crystal, while the TC4 alloy is mainly composed of interlaced acicular martensite and basketweave sstructure, both the organization of layers are in better form. The microhardness of the FeCrNiB cladding layer is 380-750 HV0.1, one time higher than the substrate. The microhardness of the TC4 cladding layer is 295-350 HV0.1, which is similar with the substrate. The dimension accuracy of the blade after remanufacture was controlled within 0.8 mm. Through the laser process optimization and performance matching analysis, the FeCrNiB alloy was suitable for local microcrack remanufacture, while the TC4 alloy was suitable for the forming of volume damage.