莫来石短纤维增强Al-4.5Cu复合材料的时效析出行为  

Ageing Precipitation of Short Mullite Fiber Reinforced Al-4.5Cu Composite

作　　者：李伟[1] 范洪远[1] 沈保罗[1] 高升吉[1] 涂铭旌[1] 王鸿华[2] 吴桢干[2] 张荻[2] 吴人洁[2] 

机构地区：[1]四川大学制造科学与工程学院,四川成都610065 [2]上海交通大学金属基复合材料国家重点实验室,上海200030

出　　处：《矿冶工程》2002年第4期84-87,共4页Mining and Metallurgical Engineering

基　　金：国家自然科学基金 (59631 0 80 );上海交大金属基复合材料国家重点实验室资助项目

摘　　要：用差示扫描量热仪 (DSC)和透射电镜 (TEM)对莫来石 (Mullite)短纤维增强Al 4 .5Cu复合材料及其基体合金的时效析出行为进行了研究。结果表明 :淬火态复合材料界面附近基体一侧中存在高密度位错 ;复合材料DSC曲线低温段GP区的形成和溶解被严重推延和抑制 ,而中高温段θ″和θ′相的析出则明显快于基体合金 ;190℃时效时 ,复合材料DSC曲线上θ′相析出放热峰随时效时间的增加而快速衰退 ,而基体合金DSC曲线上θ′相析出放热峰衰退相对较慢 ,表明纤维对θ′相的析出具有明显的加速作用。TEM研究表明 :同一时效条件下 ,θ′相在复合材料中的析出数量较多、尺寸较大 ,θ′相与Al基体有良好的晶体学共格关系。The age-precipitation behaviour of the short mullite fiber reinforced Al-4.5Cu composite and its monolithic alloy has been studied by means of differential scanning calorimetry (DSC) and transmission electron microscope (TEM). It is shown that there exists highly densified dislocation in the vicinity of the fiber/matrix interface in the quenched composite, and that GP zone formation in the composite is heavily delayed or suppressed but the precipitation of θ″and θ′phases is apparently accelerated compared to its monolithic alloy based on DSC measurement. In as aged conditions at 190 ℃, the onset and dissolution peaks on DSC thermograms of Mullite/Al-4.5Cu composite fade down faster than those of Al-4.5Cu base alloy, indicating that metastable phases in the composite precipitate much faster than those in the monolith. It is also shown, based on TEM observation, that both the amount and the magnitude of θ′precipitates in the composite are much greater than those in the base alloy aged at the same condition, and that θ′and Al are crystally semi-coherent both in Mullite/Al-4.5Cu composite and in Al-4.5Cu alloy.

关 键 词：析出 时效 复合材料 莫来石短纤维 铝铜合金 

分 类 号：TB333[一般工业技术—材料科学与工程]