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研究了强流脉冲电子束表面改性处理对过共晶铝硅合金(Al-17.5Si)组织和性能的影响。利用扫描电镜和X射线衍射分析了改性机理。扫描电镜结果表明,在电子束处理后的合金表面上,硅元素扩散到铝基体中形成单相α固溶体。X射线衍射分析指出,电子束处理后合金表面没有新的物相生成,并在15脉冲处理后铝的晶格参数显着降低。硬度结果表明,在铝硅扩散区域,初生硅的硬度从中心向边缘呈现梯度分布趋势,而且初生硅中心处的硬度随脉冲次数的增加逐渐减小。耐磨性随脉冲次数的增加先提高后降低,磨损量在15次脉冲后降低了84.6%。因此该技术在改善过共晶铝硅合金表面耐磨性方面展现了良好的应用前景。
The effect of high current pulsed electron beam surface modification on microstructure and properties of hypereutectic Al-Si alloy (Al-17.5Si) was studied. The modification mechanism was analyzed by scanning electron microscopy and X-ray diffraction. Scanning electron microscopy results showed that silicon diffused into the aluminum matrix to form single-phase α solid solution on the electron-beam-treated alloy surface. X-ray diffraction analysis indicates that there is no new phase formation on the alloy surface after electron beam treatment and the lattice parameter of aluminum is significantly reduced after 15 pulse processing. The results of hardness show that the hardness of primary silicon presents a gradient distribution from the center to the edge in the area of Al-Si diffusion, and the hardness at the center of primary Si decreases with the increase of pulse number. The wear resistance increased first and then decreased with the increase of pulse frequency, and the wear loss decreased 84.6% after 15 pulses. Therefore, the technology has shown a good application prospect in improving the wear resistance of the hypereutectic Al-Si alloy surface.