材料期刊网

测试二元NiAl合金、NiAl--Al2O3--TiC原位内生复合材料以及NiAl--Cr(Mo)--Hf共晶合金的室温摩擦磨损性能, 研究了磨损机制. 结果表明: NiAl材料的抗磨损性能与材料的硬度和断裂韧性成正比, 在磨损过程中硬质陶瓷颗粒能有效地传递应力和起到支撑作用, 减轻材料的磨损. 因此NiAl--Al2O3--TiC复合材料的抗磨损性能最好, 在相同工况下其磨损率为NiAl--Cr(Mo)--Hf共晶合金的1/4-3/4和二元NiAl合金的1/20-1/10. 摩擦系数随着三种NiAl材料硬度的提高而降低. 三种NiAl材料的室温干摩擦磨损过程受控于塑性变形, 其磨损机制主要是磨粒磨损机制, 随着载荷的增加, 磨损表面依次呈现出塑性变形、显微剥落和粘着磨损特征, 磨损机制的改变对磨损率和摩擦系数具有重要的影响.

The friction and wear properties of NiAl, NiAl--Cr(Mo)--Hf eutectic alloy and NiAl--Al2O3--TiC composite were investigated with an MRH-5A friction and wear tester. The results showed that the wear resistance of NiAl-based alloys was directional propertional to their hardness and fracture toughness and the friction coefficient  ecreased with the increasing hardness. Among the above three alloys, NiAl--Al2O3--TiC composite possessed the best friction and wear properties. The wear mass loss only one-fourth to three-fourthes of that of NiAl--Cr(Mo)--Hf eutectic alloy or one-twentieth to one-tenth of that of NiAl alloy, which was attributed to the efficient transferring stress and supporting effect of reinforcing ceramic particles. The wear process of three NiAl materials is dominated by plastic deformation, and the main wear mechanism of the three NiAl--based alloys was abrasive wear. With the increase of load, the wear surfaces exhibit orderly such wear mechanisms as distinct plastic deformation, spalling and adhesion wear. The wear mechanism played an important role in the wear rate and friction coefficent.