【作者】 姜龙涛； 姜瑞姣； 孙兴国；

【Author】 Jiang Longtao,Jiang Ruijiao,Sun Xingguo (School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001)

【机构】 哈尔滨工业大学金属复合材料与工程研究所；

【摘要】 本文采用压力浸渗法制备了Mg质量分数为2.0%和2.5%,体积分数为30%的0.15μm-Al₂O₃p/Al-Cu-2.0Mg和0.15μm-Al₂O₃p/Al-Cu-2.5Mg复合材料。利用硬度测试、DSC分析和TEM观察的方法研究了这两种复合材料及其基体合金的时效硬化行为。结果表明,加入Al₂O₃颗粒后,两种Mg含量的复合材料的硬度值明显高于基体合金;随Mg含量提高,峰时效温度提前,复合材料和基体合金的硬度值均略有增加。DSC分析发现,基体合金中存在明显的GPB区与亚稳相的放热峰,复合材料中的GPB区受到抑制,只有一个平缓的亚稳相的放热峰存在;对于复合材料和基体合金,析出相的放热峰都随Mg含量的增加向高温移动;添加Al₂O₃颗粒,不改变复合材料的时效析出顺序。TEM观察表明基体合金的时效强化作用以过渡相的沉淀析出为主;复合材料的强化机制为时效强化和固溶强化的综合作用。更多还原

【Abstract】 The 0.15p m 30%Al₂O_3p/Al-Cu-2.0Mg and Al₂O_3p/Al-Cu-2.5Mg composites were fabricated by pressure infiltration method,The aging behaviors of composite and the corresponding matrix alloy were investigated by means of Brinell hardness test and Differential scanning calorimeter（DSC）.Results showed that the hardness for the two composites improved significantly after the addition of hard ceramic particles.The aging behavior of alloy matrixes and composites of both material systems behaved slightly and the peak-aging time was put ahead as Mg content increased.DSC analysis showed the aging precipitation sequence of Al₂O_3p/Al-Cu-Mg is the same as that of the matrixes.The addition of sub-micron alumina particles restrained the formation of GPB zone and the exothermic reaction peaks became wide and gentle in the DSC curves.For the composites and the alloy matrixes,all the exothermic peaks have moved to high temperature with the increasing of Mg contents.TEM observation showed that the composites’ strengthen mechanism is different from that of the alloy matrixes.更多还原