激光合成Ni85Al15掺杂钨精矿粉合金组织及性能研究

为了提高复合材料的硬度、强度及耐磨性能,采用高能束激光诱发自蔓延原位自生反应合成金属陶瓷颗粒增强复合材料的方法,在过共晶Ni85Al15粉末中添加质量分数为0.01,0.015和0.02的钨精矿粉并压制成坯激光烧结后,得到了烧结合金的X射线衍射和扫描电子显微硬度、磨损测试结果。未添加钨精矿粉时,烧结合金的合成产物主要有NiAl,Ni3Al和Al2O3等相;添加钨精矿粉后,烧结合金产物增加了Ni4W和WO3相;当钨精矿粉的质量分数为0.01时,烧结合金相对密度最高为5.84g/cm3,其孔隙率最低为0.13%,合金硬度最高为325.2HK,磨损率最低为0.27mg/mm2。结果表明,钨精矿粉的加入,能够增加材料的硬度及其耐磨性能,当其质量分数达到0.01时,材料的硬度和材料的耐磨性能最优。

Microstructure and properties of Ni85Al15 composite material blended with tungsten concentrate powder by laser synthesis

In order to increase the hardness, strength and wear resistance of the compound material, based on the in-situ synthesis self-propagation reaction induced by high energy laser, the NiAl composite material was prepared by synthesizing the reinforced metal-ceramic hard particles. Added 0.01, 0.015 and 0.02 (mass fraction w) of tungsten concentrate powder respectively, combined hypereutectic Ni85Al15 powder was pressed into three kinds of billets. After sintering, the results of the the X-ray diffraction(XRD), secanning electron microscope(SEM), hardness and wear resistance of the sintering alloy were obtained. The results show that when the tungsten concentrate powder is not added, the main product phase of the sintering alloy are NiAl, Ni3Al and Al2O3; while if the tungsten concentrate powder is added, the sintering alloy products will produce Ni4W and WO3 phase on the side. When the mass fraction of tungsten is 0.01, the relative density of the sintering alloy is the biggest, which is 5.84g/cm3; the porosity rate is the lowest, which is 0.13%; the hardness rate of the sintering alloy is the highest, which is 325.2HK; the wear rate is the lowest, which is 0.27mg/mm2. The results show that the powder of tungsten concentrate can increase the hardness and wear resistance of the material, the material has the best hardness and wear resistance when its mass fraction is 0.01.