TEM in situ study of isothermally induced cracking in the near-interface region of an SiCw/6061AI composite

摘要

Most of the metal matrix composites (MMCs) are designed to be used as elevated temperature struc-tural materials. Hence, their elevated temperature strength, thermal cycling and isothermal exposure resistance are studied extensively [1-9], with par-ticular focus on the continuous fibre reinforced MMCs. The results show that the degradation of continuous fibre reinforced MMCs exposed to elev-ated temperature is attributed to damage at the fibre-matrix interface and/or the fibre itself [1-4]. For whisker or participate reinforced MMCs, such as silicon carbide whisker reinforced aluminium (SiCw/Al) composites, the data of isothermal ex-posure is limited [2, 9]; to date, it can be concluded that the strength of the composites decrease after they are isothermally exposed.