Stress, strain and elastic modulus behaviour of
SiC/SiC composites during creep and cyclic fatigue
رفتار تنش، کرنش و مدول کشسانی کامپوزیت SiC/رشته ی SiC
در آزمون خرش و خستگی چرخه ای
ABSTRACT
Creep and fatigue tests of Hi-NicalonTM/SiC (SiC matrix contains glass-forming, boron-based particulates), Standard SiC/SiC (SiC matrix is pure SiC) and Enhanced SiC/SiC (SiC matrix contains glass-forming, boron-based particulates) were carried out in air at 1300°C. The stress–strain hysteresis loops during fatigue and creep were studied. The change of Young’s modulus during creep and fatigue was analysed and compared among the three kinds of materials. Creep strain rates of Hi-NicalonTM/SiC in air were similar to those of Enhanced SiC/SiC, but much lower than those of Standard SiC/SiC. Consequently, the time to rupture at a given stress in Hi-NicalonTM/SiC was similar to that in Enhanced SiC/SiC, but much longer than in Standard SiC/SiC. Fatigue resistance of Hi-NicalonTM/SiC was similar to that of Enhanced SiC/SiC, but much better than Standard SiC/SiC.
چکیده
آزمون های خزش و خستگی Hi-Nicalon SiC/SiC در هوا در دمای °C 1300 انجام شد، و آزمون های خزش همچنین در آرگون در دمای °C 1300 انجام گردید. زمان گسیختگی تحت بارهای خزشی اندکی نسبت به بارهای خستگی با یک حداکثر تنش مشخص کوتاهتر بود. زمان گسیختگی در یک تنش مشخص در هوا طولانیتر از آرگون بود. هر دو مقاومت خزشی و خستگی Hi-Nicalon SiC/SiC مشابه با مقاومت های SiC/SiC ارتقا یافته و بسیار بهتر از مقاومت های SiC/SiC استاندارد بود.