激光烧结钨基合金组织性能研究

采用激光烧结技术制备了钽、铼掺杂钨基合金，利用扫描电子显微镜、金相显微镜、X射线衍射仪和显微硬度计等设备表征了钨基合金试样的组织和性能。结果表明，激光功率及激光扫描速度是影响钨合金块体相对密度的重要因素，通过对参数的优化可获得致密的钨合金块体材料；通过粉体解吸脱氧预处理和惰性气体保护可以避免粉体的氧化；显微组织观察表明，在激光烧结过程中，试样内部发生了静态再结晶；在试样芯部形成了较粉体颗粒明显增大的等轴晶粒，在试样边缘形成了尺寸略大于粉体粒径的等轴晶粒；X射线衍射测试结果表明，加入的钽元素在钨基体中以固溶原子的形式存在；性能测试结果表明，随着钽加入量的增加，试样的密度下降，但显微硬度随之提高。

Study on microstructure and properties of tungsten alloy prepared by laser sintering

The tantalum and rhenium doped tungsten-based alloys were prepared by laser sintering, and the microstructure and mechanical properties of the tungsten-based alloy samples were investigated by scanning electron microscope (SEM), optical microscope (OM), X-ray diffraction (XRD), and micro-hardness tester. The results show that, the laser power and laser scanning speed are the important factors affecting the relative density of tungsten alloy blocks, the compact tungsten alloy block materials are obtained by optimizing the parameters. The powder oxidation is avoided by the desorption and deoxygenation pretreatment and the inert gas protection. The microstructures show that, the static recrystallization occurs in the laser sintering process. The equiaxial grains with the significantly larger size than the powder grains are formed at the core of the tungsten-based alloy sample, and the equiaxial grains with the size slightly larger than the powder grains size are formed at the edge of the tungsten-based alloy sample. The XRD results show that, the doped tantalum element exists as the solid dissolved atoms in tungsten matrix. The performance testing results show that, the density decreases with the increase of tantalum, but the microhardness increases.