中文摘要：

采用激光熔化沉积方法制备出Rene95镍基高温合金薄壁样，分析了沉积态的凝固组织，并进行了热处理和力学性能测试。研究表明，激光熔化沉积Rene95镍基合金的凝固组织为外延生长的定向凝固组织，其一次枝晶间距在20μm左右，二次枝晶臂细小甚至退化，元素偏析较轻；通过适当的热处理后，合金中γ′沉淀相的体积分数明显增加，合金的显微硬度由沉积态的HV0.1 500提高到HV0.1 540；经过热处理后，激光熔化沉积Rene95合金的室温抗拉强度为1247MPa，较粉末冶金C级水平略低，而沿沉积高度方向的延伸率为16．2％，高于粉末冶金A级水平。

英文摘要：

Thin wall samples from Rene95 nickel based superalloy were prepared by laser direct deposition. The solidification microstructure, heat treatment process and the mechanical properties of the deposited materials were analyzed and tested. The results indicated that the as-deposited microstructure was directionally solidified dendrites. The primary dendrite arm space was about 20 μm and the secondary dendrite arm was smaller or somewhat degenerated. There was little composition segregation within the deposited materials. After proper heat treatment, the volume frac- tion of γ′precipitates increased and micro-hardness increased from HV01 500 to HVo.1 540. The room temperature tensile strength of the as-deposited Re- ne95 superalloy was 1247 MPa, which was lower than of powder metallurgy for level C, while the ductil- ity along the deposition direction was 16.2%, which was much higher than that of powder metallurgy for level A.