Modeling the Age-Hardening Behavior of SiC/Al Metal Matrix Composites
Modeling the Age-Hardening Behavior of SiC/Al Metal Matrix Composites
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DOI：
10.1007/s11661-006-9064-7
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发表时间：
2007-03
期刊：
影响因子：
--
通讯作者：
M. Song;Xia Li;Kang Chen
中科院分区：
文献类型：
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作者：
M. Song;Xia Li;Kang Chen
建立了碳化硅/铝基复合材料的时效硬化模型，描述了屈服强度随时效时间的变化规律。该模型考虑了析出相沿位错的异质形核和长大来描述加速时效行为。结果表明，碳化硅颗粒的尺寸和体积分数以及时效温度影响时效硬化行为。随着时效温度的升高，由于溶质原子扩散速度的提高，总形核率(单位时间形核率之和)和析出相的生长速度加快，从而加速了时效过程。减小碳化硅颗粒的尺寸和增加碳化硅颗粒的体积分数，由于位错密度的增加，提高了总的形核率，从而加速了时效过程。结果表明，对于片状析出物和针状析出物的Al-Mg-Si合金和碳化硅增强Al-Cu-Mg合金，该模型均能很好地预测其屈服强度。
A model for the age-hardening behavior of SiC/Al metal matrix composites has been developed to describe the variation of the yield strength with aging time. The model incorporates the heterogeneous nucleation and growth of the precipitates along the dislocations to describe the accelerated aging behavior. It has been shown that the size and volume fraction of the SiC particles as well as aging temperature influence the age-hardening behavior. Increasing the aging temperature accelerates the aging process by increasing the velocities of the total nucleation rate (the sum of the nucleation per unit time) and growth of the precipitates due to the enhanced diffusion velocity of the solute atoms. Decreasing the size and increasing the volume fraction of the SiC particles also accelerate the aging process by enhancing the total nucleation rate due to the increased dislocation density. It was found that the yield strengths have been well predicted by the model for both SiC-reinforced Al-Cu-Mg alloy and Al-Mg-Si alloy, which have plate-shaped and needle-shaped precipitates, respectively.