基于稀土调控的激光熔覆Ni60强化铝合金的高温摩擦磨损性能研究

High Temperature Friction and Wear Properties of Laser Cladding Ni60 Coating Modified with Rare Earth on 6063 Aluminum Alloy Base

目的提高铝合金的综合使用性能。方法采用激光熔覆技术对6063铝合金表面分别进行了Ni60、Ni60+4%CeO2、Ni60+5%Y2O3和Ni60+5%La2O3激光熔覆处理,然后进行了硬度和高温摩擦磨损实验,通过分析各试样的摩擦系数、磨痕轮廓、磨损量、物相、成分和磨损后微观形貌,进而分析各试样的耐磨性能和磨损机理,以及稀土对熔覆层耐磨性能和磨损机理的影响。结果熔覆层的硬度呈梯度分布,加入稀土Ni60熔覆层的硬度明显提升。6063铝合金随着载荷和磨损温度的升高,磨损机制从二体磨粒磨损,到粘着磨损,再到严重的熔融磨损和氧化磨损,由轻微向严重磨损转变。Ni60熔覆层的磨损机制主要为剥层磨损、氧化磨损和轻微的犁削磨损,并随着载荷和磨损温度的升高,剥层磨损的程度越来越严重。添加最佳稀土含量的熔覆层随着载荷和磨损温度的升高,磨损机制逐渐由以犁削磨损为主过渡为以剥层磨损为主,并含有氧化磨损和犁削磨损。与Ni60熔覆层相比,加入最佳稀土含量的熔覆层的高温摩擦磨损性能均有明显提高。结论对比三种稀土熔覆层,高温摩擦磨损性能由好到差的顺序为Ni60+4%CeO2熔覆层>Ni60+5%Y2O3熔覆层>Ni60+5%La2O3熔覆层。

In order to improve the comprehensive performance of aluminum alloy,the surface of 6063 aluminum alloy was modified with Ni60,Ni60+4%CeO2,Ni60+5%Y2O3 and Ni60+5%La2O3 by using laser cladding technology.Hardness experiments,high temperature friction and wear behaviors were carried out.The wear resistance and wear mechanism of each sample and the influence of rare earth on the wear resistance and wear mechanism of the cladding layer by analyzing the friction coefficient,wear tracks,wear amount,phase,composition and micro-morphology after wear of the sample.The hardness of the cladding layer added with rare earth increase significantly and the hardness of the cladding layer presented a gradient distribution.With the increase of load and wear temperature,the wear mechanism of 6063 Al changed from mild to severe wear,the order was two-body abrasive wear to adhesive wear,and then,to severe melting wear and oxidative wear.The wear mechanism of Ni60 cladding layer was mainly peeling wear,oxidation wear and slight ploughing wear.With the increase of load and wear temperature,the degree of peeling wear became more and more serious.With the increase of load and wear temperature of the cladding layer with the optimal rare earth content,the wear mechanism gradually changed from ploughing wear to delamination wear,and contained oxidation wear and plough wear.Compared with the Ni60 cladding layer,the high-temperature friction and wear properties of the cladding layer with the best rare earth content were significantly improved.Compared with the three kinds of rare earth cladding layers,the order of high temperature friction and wear performance from good to poor is Ni60+4%CeO2 cladding layer,Ni60+5%Y2O3 cladding layer,Ni60+5%La2O3 cladding layer.