Fe含量对挤压铸造Al-Cu合金组织演变及高温力学性能的影响

发布时间：2018-01-18 14:39

本文关键词：Fe含量对挤压铸造Al-Cu合金组织演变及高温力学性能的影响　出处：《中国有色金属学报》2017年05期 　论文类型：期刊论文

【摘要】：采用拉伸性能测试、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等研究Fe含量对挤压铸造Al-Cu合金组织演变及高温力学性能影响。结果表明:随着Fe含量的增大,铝铜合金的常温和高温性能急剧下降,这主要是由于针状富铁相增多,同时铝铜合金基体中强化相减少。而耐热富铁相可以一定程度上阻碍晶界高温滑移,Fe含量对合金高温力学性能的影响没有常温性能那么敏感。挤压压力可以显著提高合金的高温性能,尤其是合金的伸长率,但与常温力学性能相比,挤压压力对高温力学性能的提升幅度下降。同时,挤压铸造铝铜合金的高温伸长率在Fe含量为0.5%(质量分数)的附近存在一个峰值。这主要是由于挤压压力下合金致密,富铁相尺寸变得细小,针状富铁相大幅减少,同时晶粒细化导致高温下晶界弱化加剧。
[Abstract]:The tensile properties were tested by scanning electron microscope (SEM). The effect of Fe content on microstructure evolution and high temperature mechanical properties of squeeze casting Al-Cu alloy was studied by TEM. The results showed that the content of Fe increased with the increase of Fe content. The properties of Al-Cu alloy decreased sharply at room and high temperature, which was mainly due to the increase of acicular Fe-rich phase and the decrease of strengthening phase in Al-Cu alloy matrix, while the heat-resistant Fe-rich phase could hinder the grain boundary sliding at high temperature to some extent. The effect of Fe content on the mechanical properties of the alloy at elevated temperature is less sensitive than that at room temperature. Extrusion pressure can significantly improve the high temperature properties of the alloy, especially the elongation of the alloy, but compared with the mechanical properties at room temperature. The increase of extrusion pressure on the mechanical properties of high temperature is decreased at the same time. There is a peak value of high temperature elongation of Al-Cu alloy in squeeze casting near the Fe content of 0.5 (mass fraction), which is mainly due to the compactness of the alloy under extrusion pressure and the finer size of the rich iron phase. The acicular iron rich phase decreases greatly, and grain refinement leads to the weakening of grain boundary at high temperature.
【作者单位】：贵州大学机械工程学院;华南理工大学机械与汽车工程学院;
【基金】：国家自然科学基金资助项目(51374110) 广东省自然科学基金团队项目(2005A030312003) 贵州大学引进人才科研基金资助项目(201440) 国家金属材料近净成形工程技术研究中心开放基金项目(2015009)~~
【分类号】：TG249.2
【正文快照】： 铝合金具有密度低、比强度高、导热性好等优点,广泛地应用于制造航空、交通等领域的耐热零部件。随着全球绿色经济的发展要求和能源法规限制越来越严格,对铝合金的耐热性能也提出了更高的要求。通过微合金化形成弥散析出相是提高铝合金耐热性能的一种有效手段[1]。然而,铝合金

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