The ageing behaviors of mullite short fibre reinforced Al Mg Si composites with different Mg Si ratios (Mg/Si=2.Mg/Si<2
Mg/Si> and its matrix alloy in squeezing casting were examined by means of hardness measurement (HB)
SEM
DSC and TEM.The results showed that the composites and its matrix alloy have the similar ageing hardening curves and the same precipitation procedure.Although the mullite fibre addition can improve the aged hardness and accelarate ageing hardening process of the marix alloy to some extent
the mullite fibre only silightly restrains the formation of GP zone.Excess Si or Mg not only accelarated the ageing hardening process of the composites and its matrix alloy but also obviously advanced the ageing peak of both materials.Mullite short fibre with excess Si or Mg has the interaction on ageing hardening process of the composites.
关键词
铝基复合材料莫来石短纤维Al-Mg-Si合金时效行为
Keywords
Al Matrix CompositesMullite Short FibreAl-Mg-Si AlloyAgeing Behavior