Cu-Cr-Zr-Nb合金组织及耐磨性研究

Microstructure and Wear Resistance of Cu-Cr-Zr-Nb Alloy

借助Nb元素在Cu-Cr-Zr合金中的作用,通过真空感应熔炼结合两步轧制-时效工艺制备Cu-Cr-Zr-Nb合金,并对其组织及耐磨性进行了研究。结果表明:经过两步轧制-时效工艺的合金中存在着大量的位错、纳米析出相和纳米变形孪晶,使合金的强度显著提升。通过Nb元素合金化,在合金中引入了均匀分布的Cr_(2)Nb微米颗粒,同时在合金中存在微米和纳米尺度Cr颗粒,利用微米和纳米颗粒的协同强化使合金的性能提升。针对其耐磨性,铸态合金的摩擦系数在0.6以上,体积磨损量随实验载荷的增加而增加。经过轧制-时效工艺,由于合金强度和硬度的提升,其摩擦系数下降至0.6以下,体积磨损量稳定在0.2 mm^(3)以下,磨损机制主要以粘着磨损和疲劳磨损为主。

Cu-Cr-Zr-Nb alloy was designed by considering the role of Nb element in Cu-Cr-Zr alloy.The alloy samples were prepared by vacuum induction melting and a two-step rolling-aging process,and their microstructure and wear resistance were studied.The results showed that a large number of dislocations,nano-precipitates,and deformation twins existed in the samples after the two-step rolling-aging process,which improved the strength of the alloy.By alloying Nb element,uniformly distributed Cr_(2)Nb particles were introduced into the alloy,and micro-and nano-sized Cr particles were observed in the alloy.The properties of the alloy were effectively enhanced by the synergistic effect of micro-and nano-sized particles.The friction coefficient of the as-cast samples was generally above 0.6,and the volume wear increased with the increase of the experimental load.After the rolling-aging process,the friction coefficient of the aging samples decreased to less than 0.6 due to the increase in strength and hardness,and the volume wear was below 0.2 mm^(3) steadily.The adhesive wear and fatigue wear were the main wear mechanism.