SiCp增强Al基复合材料在应变过程中显微组织的损伤

采用恒定应变速率拉伸试验研究了币喷射成型制成的１５ＳｉＣｐ／Ａｌ－１６１８复合材料在４３８和４９３Ｋ下的应变行为。对不同应变速率下ＳｉＣｐ／Ａｌ－２６１８的应力－应变曲线的分析表明，颗粒复合材料表现出一个临界应变速率的行为，对不同应变条件下ＳｉＣｐ损务数量的定量统计分析表明。

THE MICROSTRUCTURAL DAMAGE DURING DEFORMATION OF SiCp REINFORCED Al-2618 METAL MATRIX COMPOSITE

The deformation behaviour of a spray formed SiCp/Al-2618 MMC is investigated usingconstant strain rate tensile tests at elevated temperature. Both initial work hardening rate and uniformstrain measurements of the composite show a clear critical stain rate phenomenon but it presents a rangeof strain rates rather than a specific rate. The fraction of broken SiC particles during strain tests obtainedby microstructural observation shows that the critical strain rate behaviour is caused by the presence of theSiC particles in the composite. The critical behaviour is related to a transition from a chiefly undamagedparticle population to one of a high degree of damage. A critical strain rate/temperature model fromdislocation-particle interaction theory is used to interpret the results and to predict the process window.Using this window the process temperature and strain rate, under which the reinforced particles are notbroken during strainning, can be determined appropriately.