关键词: 机械合金化, Al 基轴承合金, 纳米复合结构, 摩擦摩损性能

Abstract:

AI-Pb and AI-Sn bearing alloys were obtained by sintering the AI-Pb and AI-Sn powder mixtures preparedvia mechanical alloying. According to the microstructures of the alloys characterized by means of XRD , SEMand TEM , the Pb or Sn soft phase in a size of about 100 nm homogeneously disperses in AI matrix of the alloys fabricatedunder appropriate mechanical alloying and sintering conditions. It is indicated by the wear test that the AIbasedbearing alloys containing nano-sized Pb or Sn dispersoids are of excellent wear properties. Moreover , accordingto the coarsening behavior of the nanophase particles , the nano-composite structure possesses good stability andthe growth of the second phase still follows the classical ripening theoηdescribed by LSW equation. As for theeffect of the contamination induced by milling on the microstructure of Al-based bearing alloys , the Al₇ Cu₂ Fe phaseforms owing to the Fe contamination , and the adherence of nano-sized Al₂ O₃  phase to Pb particles occurs due to theoxygen contammatlOn.

Key words: mechanical alloying, Al-based bearing alloy, nano-composite structure, wear property