http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
조인식(Insik Cho),전용호(Yongho Jeon),신충식(Choongshig Shin),곽동호(Dongho Kwak),이지용(Jiyong Lee) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10
Due to the extensive long service life for aero-space components, the behavior of very high cycle fatigue(VHCF) is gained attention. For this reason, the newly developed piezoelectric ultrasonic fatigue test (UFT) system by Mbrosiatec Co. Ltd is used to investigate the high cycle fatigue (HCF) strength of Ti-6Al-4V alloy. The hourglass-shaped specimens are investigated in the range of 10<SUP>6</SUP> to 10<SUP>9</SUP> cycles at room temperature under completely reversed loading conditions R=-1. Scanning electron microscopy(SEM) analysis revealed that failures occur right up to the gigacycle regime, with the fractures being found to initiate from the surface unlike in steels. In addition, SEM micrographs showed that micro-cracks were transformed into intergranular fracture. Additionally, this test method can be applicable on commercialized parts of automotive and rail road which are required high cycle fatigue. In addition, SEM micrographs showed that micro-cracks were transformed into intergranular fracture.