表面纳米化对2024铝合金耐磨性能的影响

Effects of Surface Nano Crystallization on Wear Resistance of 2024 Aluminum Alloy

为了提高2024铝合金的耐磨性,采用超声波冷锻技术在2024铝合金表面进行纳米化处理,在其表面成功制备了纳米化处理层。利用透射电镜(TEM)和原子力显微镜(AFM)观察分析了试样表面的微观形貌、晶粒大小和粗糙度;利用显微硬度计分析了铝合金基体和纳米化处理层的硬度;采用高速往复摩擦磨损试验机研究了纳米化处理层在3.5%Na Cl溶液中的耐磨性。结果表明:经超声波冷锻处理后铝合金表面晶粒得到细化;纳米化处理层的平均表面粗糙度仅为5.50 nm;纳米化处理后的硬度为106.72 HV,是铝合金基体的1.36倍;纳米化处理后的摩擦系数由0.80降到0.65,磨损量也有所减少,磨痕深度也比铝合金基体的浅。综上可得:超声波冷锻技术提高了2024铝合金的耐磨性。

In order to improve the wear resistance of 2024 aluminum alloy,ultrasonic cold forging technology(UCFT) was used to prepare a nanocrystalline coating on 2024 aluminum alloy.The microstructure,grain size and surface roughness of the sample treated by UCFT were measured by transmission electron microscope(TEM) and atomic force microscope(AFM).Micro-hardness tester was used to measure the sample hardness.The high-speed reciprocating friction and wear tester was used to test the wear performance of the samples.Results showed that the surface grains of aluminum alloy were refined by UCFT.The average surface roughness of the nanocrystalline coating was only 5.50 nm and the hardness was 106.72 HV,which was 1.36 times as great as that of the matrix.Besides,the friction coefficient was decreased from 0.80(the untreated sample) to 0.65 and the weight loss was also decreased.Meantime,the wear depth of the UCFT sample was shallower than that of the untreated sample.Therefore,the wear resistance of 2024 aluminum alloy was improved by UCFT technology.