考察了Al62Cu25.5Fe12.)准晶磨料对紫铜、2024铝合金和304不锈钢3种软金属表面的研磨行为,从表面形貌、纳米硬度、碾抹系数、磨损量和电化学阻抗等方面与传统硬磨料(金刚石、Al2O3和SiO2)进行对比.结果表明:经准晶磨料抛光的工件表面形貌与碾抹程度相关,碾抹系数越大,表面越平整,且碾抹系数与表面磨损率成反比.尤其需要指出的是,准晶磨料的这种"碾抹"特性可导致不锈钢表面产生硬化效应,硬度可提高约0.3 Gpa.准晶磨料的碾抹特性还有利于2024铝合金表面生成高耐蚀能力的钝化膜.
Polishing soft metals using hard abrasives such as diamond, alumina, and silica can easily damage the worn surface by deep scratches and by large material removal due to cutting wear mechanism. An abrasive material with appropriate hardness, hardness/elasticity ratio, and low friction is then highly desirable, which would avoid intense abrasion while at the same time minimize scratching on soft metals. Quasicrystals are characterized by low friction and high hardness/elasticity ratio, making them potentially suitable for use as abrasives for soft metals. It has been pointed out by the authors that Al Cu Fe quasicrystal abrasive shows a particular smearing dominant wear mechanism and can be used as a special abrasive for flattening soft metals. In this work, the Al62Cu25.5Fe12.5quasicrystal abrasive was chosen, to compare with conventional hard abrasives such as diamond, alumina and silica, to wear against copper, 2024 aluminum alloy and 304 stainless steel. The surface topography, nano-indentation hardness, smearing coefficient, mass loss and electrochemical impedance were measured and the results indicate that the surface flattening is influenced by the smearing coefficient, a parameter developed to assess the degree of smearing- type wearing. A larger smearing coefficient leads to a more flatten surface at the least expense of mass loss. It is specially noticed that the characteristic smearing mechanism of quasicrystal abrasive produces an obvious surface hardening effect, with the nano-hardness of 304 stainless steel being increased by about 0.3 GPa. The corrosion resistance of the Al alloy is also enhanced due to the formation of a thick and dense passive film.