摘要
采用压力浸渗法制备碳纤维织物(2D C_f)及单向碳纤维(1D C_f)增强镁合金复合材料,测试了两种复合材料在50-350℃范围内的热膨胀行为.结果表明,2D C_f/镁合金复合材料(简称2D)平面内不同方向的平均热膨胀系数均随温度升高不断降低.从50到350℃,0°/90°方向的平均热膨胀系数由4.03×10^(-6)℃^(-1)降至1.83×10^(-6)℃^(-1);45°方向的平均热膨胀系数由4.53×10^(-6)℃^(-1)降至2.31×10^(-6)℃^(-1).根据推导公式可以准确计算2D增强复合材料20—150℃范围内0°/90°方向的平均热膨胀系数.20—150℃热循环测试结果表明,2D复合材料具有较好的尺寸稳定性,在热循环过程中存在应变滞后现象,其残余塑性变形主要是基体合金在热应力作用下产生的塑性变形,并且从第2次热循环起,复合材料在热循环中产生的净应变不随热循环次数增加而变化.
Thermal expansion behaviors of carbon fabric/Mg 2.0Re 0.2Zr （2D） and carbon fabric/Mg-2.0Re-0.2Zr （1D） composites fabricated by squeeze casting technology were measured, and the results show that the anisotropy is obviously improved by using carbon fabric. Coefficient of thermal expansion （CTEs） of 0°/90° of 2D composite between 50 and 350 ℃ changes from 4.03×10^-6 ℃^ -1 to 1.83×10^-6 ℃^-1, and the 45° CTEs decrease from 4.53×10^-6℃^-1 to 2.31×10^-6℃^ -1. CTEs of 0°/90° of 2D composite between 20 and 150 ℃ are in a good agreement with the model derived by the authors. Dimensional stabilities of composites were evaluated by thermal cycling method between 20 to 150 ℃. Strain hysteresis of 2D composite is observed during thermal cycling, and residual stain is mainly matrix plastic deformation generated by thermal stress. The net strain shows little change with increasing cycling number, which demonstrated 2D composite has good dimensional stability.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2009年第1期119-123,共5页
Acta Metallurgica Sinica
