稀土CeO2对W-Ni-Fe高比重合金摩擦磨损性能的影响

摘要

W-4.9Ni-2.1Fe-xCeO2 high specific gravity alloy was prepared by applying High Energy Ball Milling and Discharge Plasma Sintering. The effects of rare earth CeO 2 dosage on the phase, microstructure, friction and wear behaviors are studied by XRD, SEM, microhardness tester and friction and wear tester. The results show that different degrees of broadening phenomenon are observed in W diffraction peak accompanied with refined particles after trace rare earth oxide's doping. The generated composite rare earth phase promotes the solid solution of Ni and Fe in W lattice. With the increase of rare earth content, the micro-hardness decreases. At the same time, the relative density first increases, then falls. The relative density reaches the maximum value when the dosage is 0.4 %. The addition of rare earth oxide CeO2 reduces the friction and wear properties of alloy samples.%采用高能球磨和放电等离子体烧结方法制备了W-4.9Ni-2.1Fe-xCeO2高比重合金，通过XRD、SEM、显微硬度计及摩擦磨损试验机等研究了稀土CeO2添加量对W-Ni-Fe高比重合金物相、显微组织及摩擦磨损行为等的影响。结果表明，微量稀土氧化物掺杂后，W衍射峰出现不同程度的宽化现象，晶粒得到细化，生成的复合稀土相CexWyOz可以促进Ni、Fe在W晶格中的固溶。随着稀土含量的增加，显微硬度不断减小，相对密度先增大再减小，当添加量为0.4%（质量分数，下同）时，相对密度达到最大。稀土氧化物CeO2的添加能降低合金试样的摩擦磨损性能。当添加量为0.4%时，粘结相分布相对较均匀，W-W之间的界面结合强度较高，合金致密化程度最高，致使磨损曲线比较稳定，对材料耐磨性能的降低效果最小。