稀土Y对纳米粉90W-Ni-Fe合金性能和微观结构的影响

Effect of Rare Earth Y on Properties and Microstructure of Nano-Powder 90W-7Ni-3Fe Alloy

采用SEM和金相仪器对添加不同Y量的纳米粉90W-7Ni-3Fe合金试样断口进行形貌观察和W晶粒测试;并对烧结态试样的相对密度、抗拉强度、延伸率等性能进行测定与分析。结果表明:当Y量在0.2%~0.6%(质量百分数,下同)时,试样相对密度为99.2%~99.6%,抗拉强度为1000MPa^1100MPa,延伸率为16%~19.5%;添加0.4%Y后,W晶粒从原来的20μm^25μm减小到12μm,W晶粒形状由不加稀土时的球形变为近球形或多边形。添加0.4%Y后,在界面上形成了W13.07Ni2.96Fe1.52Y23.65Ox(摩尔数比)的中间相,其阻止了W原子在粘结相中的扩散,阻止了W晶粒长大,细化了W晶粒,提高了合金的性能。

Effect of rare earth Y adding different contents on properties and microstructure for nano-powder 90W-7Ni-3Fe alloy were studied. Fracture morphology and W crystal sizes were measured by SEM micrographs and optical morphology, respectively. The relation density, the tensile strength and the elongation of samples were also measured and analyzed. The result show that the relation density of samples was in the range of 99.2% to 99.6%, tensile strength of samples was in the range of 1000 MPa to 1100 MPa, and elongation of samples was in the range of 16% to 19.5% when the Y content were in the range of 0.2% to 0.6 %. Average W crystal size decreased from 20μm -25 μm to 12 μm with adding 0.4% Y, and the W crystal morphology was nearly spherical or polyhedron with adding some Y. The higher rare earth content was, the bigger influencing on W crystal morphology was. Middle phase W13.07Ni2.96Fe1.52Y23.65Ox （tool ratio） was appear at interface when 0.4% Y was added, which decreased diffuse of W atom in matrix phase and prevented W crystal from growing up. Then the properties and the microstructure of alloys were improved.