Image Courtesy of http://www.mbrosia.co.kr/en/product/product0101.php Ultrasonic fatigue testing at 20 kHz has become the standard method for characterizing material fatigue in the Very High Cycle Fatigue (VHCF) regime — beyond 107 cycles, extending to 109 (gigacycle) and beyond. At 20 kHz, a test that would require… Read more
intergranular SCC of an Inconel heat exchanger tube with the crack following the grain boundaries. photo courtesy Stress corrosion cracking (SCC) is a time-dependent fracture mechanism driven by the simultaneous presence of sustained tensile stress and a corrosive environment. Neither factor alone is sufficient. Their combination… Read more
Fatigue is usually associated with tensile stresses. Engineering knowledge of compressive fatigue is very limited. Compression stresses do not cause cracks, but plastic compressive strain can cause tension stresses when the load is returned to zero and the resulting tension stress causes cracks. * *… Read more