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为改善铜基粉末冶金摩擦材料的摩擦磨损性能,研究了激光诱导表面改性制备铜基非晶-纳米晶粉末冶金摩擦材料方法。采用扫描电镜、透射电镜、X射线衍射仪及硬度计等对粉末冶金摩擦材料层微观组织及性能进行了表征,结果表明:由于激光的急速加热和冷却以及以小质点杂质形式分布于α-Cu基体中的Zn、Sn和Pb元素抑制了再结晶的形核及长大,导致铜基非晶-纳米晶粉末冶金摩擦材料的形成。同时激光表面改性处理后,α-Cu相的晶粒尺寸减小了35%,二类应变均方根值增大39%,位错密度增加97%。聚合生长状态的α-Cu产生边缘溶解,大体积α-Cu枝解细小化。摩擦材料表观硬度提高了12.7%,α-Cu相显微硬度提高了14%。耐磨性能提高45%,摩擦系数升高1%。
In order to improve the friction and wear properties of copper-based powder metallurgy friction materials, a method of laser-induced surface modification of copper-based amorphous-nanocrystalline powder metallurgy friction materials has been studied. The microstructure and properties of the powder metallurgy friction material layer were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffractometry and hardness tester. The results show that due to rapid heating and cooling of the laser, The Zn, Sn and Pb elements in the matrix suppress the nucleation and growth of recrystallization, resulting in the formation of Cu-based amorphous-nanocrystalline powder metallurgy friction material. At the same time, the grain size of α-Cu phase decreased by 35%, the root mean square of strain of the second type increased by 39% and the dislocation density increased by 97% after laser surface modification. Polymerization growth of the α-Cu edge dissolution, large volume α-Cu branch solution to the small. The apparent hardness of the friction material increased by 12.7% and the microhardness of α-Cu phase increased by 14%. Wear resistance increased by 45%, the friction coefficient increased by 1%.