飞机发动机叶片激光熔覆性能

为了修复飞机发动机叶片（K417G）的铸造缺陷和损伤，采用了500W-IPG光纤激光熔覆系统将镍基合金粉末（RCF-201）熔覆到镍基高温合金K417G基体上.利用显微镜、扫描电子显微镜（SEM）、X射线衍射（XRD）、电子探针（EPMA）和能谱仪（EDS）等分析了堆焊层的组织和成分，用显微硬度计分析了堆焊层硬度分布，用高温蠕变实验机分析了堆焊层高温蠕变性能.试验结果表明，熔覆层从熔合线到表面的组织依次由平面晶、柱状晶和等轴晶组成；熔覆层的组织为亚共晶组织，初晶相为富镍固溶体γ-Ni，共晶组织为γ-Ni+Cr₇C₃+Cr₂₃C₆+（Mo_0.54，Ti_0.46） C；熔覆层的硬度约为650 HV，约是母材硬度（350 HV）的1.86倍；在950℃/235 MPa条件下，激光熔敷试样的蠕变寿命最长约为26.17 h，且断裂位置位于母材.

Resaerch of laser cladding performance of engine blades

In order to repair aircraft engine blades (K417G) of the casting defects and damage. Ni-based alloy powder (RCF-201) was cladded on a nickel-based superalloy K417G substrate by a 500W-IPG fiber laser cladding system. The microstructure and composition of the surfacing layer were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), electron probe microanalysis (EPMA) and energy dispersive spectrometer (EDS), the hardness distribution of surfacing layer was analyzed by microhardness tester, the creep properties of surfacing layer was analyzed by high temperature creep testing machine. The results show that, the microstructure of the cladding layer from the fusion line to the surface consists of plane crystal, columnar crystal and equiaxed crystal; The microstructure of the cladding layer is hypoeutectic structure, the primary crystal phase is Ni-rich solid solution and the eutectic structure is γ-Ni + Cr₇C₃ + Cr₂₃C₆ + (Mo_0.54, Ti_0.46) C; The hardness of the cladding layer is about 650 HV, which is about 1.86 times the hardness of the base metal (350 HV); Under the condition of 950℃/235 MPa, the creep life of laser cladding specimen is about 26.17 h and the fracture position is located at the base metal.