论文部分内容阅读
研究了挤压铸造 Ａｌ_２Ｏ_３短纤维（体积分数为 １５％）增强 Ａｌ合金 Ａｌ－Ｓｉ１２－Ｃｕ１－Ｍｇ１－Ｎｉ１复合材料的变载荷蠕变和回蠕变行为．结果表明，复合材料在主应力作用下蠕变当载荷突然降低后，表现为瞬态大应变量收缩以及随后的回蠕变．研究表明初始瞬态收缩完全是复合材料的弹性应变，有别于前人采用复合材料或纯金属、合金所得到的数倍于弹性应变结果．实验结果经数值回归得出回蠕变速率，回蠕变应变 ＝Ａ ｌｎ ｔ＋Ｃ．指数ｎ在任一主应力应变阶段均接近于－１，系数Ａ取决于降载前复合材料积累的主应力蠕变状态，并随降载前主应力蠕变程度的增加而增大，表明复合材料回蠕变行为受到降载前主应力蠕变状态的制约．
The creep and creep behaviors of Al-Si12-Cu1-Mg1-Ni1 Al-Si12-Cu1-Ni1 composites reinforced by squeeze casting Al 2 O 3 short fibers (15% The results show that the composite material creeps under the action of principal stress and shows a large transient shrinkage and subsequent creep creep when the load suddenly decreases. The study shows that the initial transient shrinkage is completely elastic strain of the composite material, which is different from previous use of composite materials or pure metals, the alloy obtained several times the elastic strain results. The experimental results obtained by numerical regression creep rate, creep strain = A ln t + C. The index n is close to -1 at any stage of principal stress and strain, and the coefficient A is dependent on the creep state of the main stress accumulated by the composite before de-loading and increases with the creep extent of the principal stress before de-loading, indicating that the composite Creep creep behavior is restricted by the creep state of the principal stress before loading.