朱堂葵,杨伟,刘灵

• 1:义乌工商职业技术学院机电信息学院
• 2:南昌航空大学航空制造工程学院

摘要(Abstract)：

采用铜模喷铸制备了AZ91+0.75Ce快冷合金,研究了热处理温度及保温时间对合金非平衡组织热稳定性的影响。结果表明:铜模喷铸显著降低了镁合金的晶粒尺寸及二次枝晶间距,抑制了晶界β相形成并有效改善了Al-Ce稀土相形貌。经320℃时效处理后,快冷合金的晶界处优先形成不连续析出β相,其体积分数随时效时间的延长而增加,同时晶粒内部形成细小弥散的Al-Ce相。当时效温度升高到370℃时,快冷合金中初生α-Mg相形貌由枝晶转变为细小多边形,β相体积分数显著下降。由于Al-Ce析出相对高温晶粒生长的钉扎效应,快冷合金细晶组织的热稳定性得到提高。由于细晶强化和固溶强化的综合影响,快冷合金显微硬度为103 HV0.2,相比铸态合金提高了43%。经320℃时效处理8 h后,晶界的不连续析出β相及晶内连续析出的Al-Ce相导致合金硬度增加到129 HV0.2,相比原始快冷合金提高了25.2%。

关键词(KeyWords)： 稀土镁合金;冷却速率;非平衡凝固;热稳定性

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金(51461032,52061032);; 义乌工商职业技术学院重点科研项目(ZD2021CS414-02);; 江西省教育厅资助项目(GJJ180513)

作者(Author): 朱堂葵,杨伟,刘灵

DOI: 10.13289/j.issn.1009-6264.2021-0249

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