Study of the damage mechanisms in an OSPREY™ Al alloy-SiCp composite by scanning electron microscope in situ tensile tests
Study of the damage mechanisms in an OSPREY™ Al alloy-SiCp composite by scanning electron microscope in situ tensile tests
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DOI：
10.1016/0921-5093(94)09713-5
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发表时间：
1995-06
期刊：
影响因子：
6.4
通讯作者：
E. Maire;C. Verdu;G. Lormand;R. Fougères
中科院分区：
文献类型：
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作者：
E. Maire;C. Verdu;G. Lormand;R. Fougères
采用扫描电镜对7049铝合金+ 15% SiCpmetal基复合材料表面沉积金微网格的原位拉伸损伤机理进行定性和定量研究。第一个损伤机制被发现是最拉长的颗粒的破裂和较小比例的颗粒-基质界面的脱黏。高长径比、大尺寸和小局部体积分数的颗粒增加了裂纹的可能性。采用考虑基体弹塑性特性的Eshelby迭代法，计算了复合材料在热处理和机械载荷作用下的应力场。对损伤颗粒的统计特性的了解允许对两种观察到的损伤起裂机制的临界应力进行估计。在颗粒开裂的情况下，这种应力取决于颗粒的大小。
Damage mechanisms in a 7049 Al alloy + 15% SiCpmetal matrix composite were studied qualitatively and quantitatively by in situ tensile tests in a scanning electron microscope with gold microgrids deposited onto the surface of the specimen. The first damage mechanisms were found to be rupture of the most elongated particles and, in smaller proportion, decohesion of the particle-matrix interface. A high aspect ratio, large size and low local volume fraction of particles appeared to increase the cracking probability. An Eshelby iterative method modified to account for the elastoplastic behaviour of the matrix was used to calculate the stress field induced by the thermomechanical treatment and mechanical loading of the composite. Knowledge of the statistical characteristics of the damaged particles permitted estimation of the critical stress for the two observed damage initiation mechanisms. In the case of particle cracking this stress depends on the particle size.