超声冲击细化FGH95镍基高温合金激光熔覆层组织

发布时间：2018-12-27 06:32

【摘要】：采用超声冲击工艺对FGH95镍基高温合金激光熔覆层进行处理.利用金相显微镜分析超声冲击前后激光熔覆层微观组织的变化特征,采用图像分析软件Image-Pro Plus测量晶粒尺寸,并对超声冲击处理前后熔覆层截面的显微维氏硬度进行了对比分析.结果表明,超声冲击处理后熔覆层发生塑性变形,并沿深度方向晶粒具有不同程度的细化.强塑性变形区内位错塞积现象显著,熔覆层组织形成细化的小晶块;次塑性变形区深度范围为0.1~0.25 mm,其微观组织中存在大量细化的树状枝晶;微塑性变形区内等轴晶细化至5.4μm,细化深度达0.7 mm.超声冲击处理后熔覆层显微维氏硬度显著增大,表面显微维氏硬度值最大为594.25 HV,相比未经冲击熔覆层提高1.3倍.
[Abstract]:The laser cladding layer of FGH95 nickel-based superalloy was treated by ultrasonic impact technology. The microstructure of laser cladding layer before and after ultrasonic impact was analyzed by metallographic microscope, and the grain size was measured by image analysis software Image-Pro Plus. The microhardness of the cladding section before and after ultrasonic impact treatment was compared and analyzed. The results show that the cladding has plastic deformation and grain refinement along the depth direction after ultrasonic impact treatment. In the strong plastic deformation zone, the dislocation slug accumulation phenomenon is obvious, the microstructure of the cladding layer forms fine small crystal blocks, the depth range of the secondary plastic deformation zone is 0.1? 0. 25 mm, and there are a large number of fine dendritic dendrites in the microstructure. In the microplastic deformation zone, the equiaxed grain is refined to 5.4 渭 m, and the refining depth is 0.7 mm.. After ultrasonic impact treatment, the Vickers hardness of the cladding layer increases significantly, and the maximum Vickers hardness of the surface layer is 594.25 HV, which is 1.3 times higher than that of the unimpacted cladding layer.
【作者单位】：南京航空航天大学机电学院;
【基金】：国家自然科学基金资助项目(51475238) 航空科学基金资助项目(2011ZA52007) 中央高校基本科研业务费专项资金资助项目(30820122011ZA52007) 南京航空航天大学研究生创新基地(实验室)开放基金资助项目(kfjj120216)
【分类号】：TG174.4

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