Mullite/Al-4.5Cu复合材料的时效特性

Ageing Characteristics of Mullite Short Fibre Reinforced Al-4.5Cu Composite

选用挤压铸造法制备mullite/Al 4 5Cu复合材料 ,采用硬度测试 (HB)、差示扫描量热 (DSC)、透射电镜 (TEM)等手段研究了mullite/Al 4 5Cu复合材料的时效特性。结果表明 :莫来石纤维的引入明显提高了基体合金的时效硬度 ,加速了基体合金的时效硬化速度 ,对SSS→GPI反应有抑制作用 ,但没有改变基体合金的时效析出序列。复合材料具有和基体合金相似的时效硬化曲线。温度对两类材料时效硬化行为的影响基本一致。

Mullite short fibre reinforced Al 4 5Cu composite was fabricated through squeeze casting.Ageing characteristics of mullite/Al 4 5Cu was studied by differential scanning calorimetry(DSC),transmission electron microscopy(TEM)and hardness tester(HB).It is shown that,whether the composite or its base alloy,both of them have the similar age hardening curves.The age hardness of Al 4 5Cu alloy is obviously increased and the age hardening progress is also obviously accelerated when synthesized with short mullite fibres.Mullite fibre has suppressed the GP zone formation but not changed the precipitation sequence of the base alloy.Temperature hasthe similar effect on the ageing behavior of mullite/Al 4 5Cu composite and its base alloy.