Fatigue small crack growth threshold determination of a high-Nb TiAl alloy at different temperatures by in-situ observation
来源期刊：International Journal of Minerals Metallurgy and Materials2013年第12期
论文作者：Min Zhang Xi-ping Song Long Yu Hong-liang Li Ze-hui Jiao Hui-chen Yu
文章页码：1192 - 1197
摘 要：The purpose of this paper is to estimate the fatigue crack growth threshold of a high-Nb TiAl alloy at the different temperatures based on scanning electron microscopy（SEM）in-situ observation.The results indicated that the fatigue crack growth threshold ΔK th of a nearly lamellar high-Nb TiAl alloy with 8% Nb content at room temperature and 750 ℃ was determined as 12.89 MPa·m 1/2 and 8.69 MPa·m 1/2,respectively.The effect of the elevated temperature on the fatigue crack growth threshold cannot be ignored.At the same time,the early stage of fatigue crack propagation exhibited multicrack initiation and bridge-link behavior.
Min Zhang1，Xi-ping Song1，Long Yu1，Hong-liang Li1，Ze-hui Jiao2，Hui-chen Yu2
1. State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing2. Testing Research Center for Aeronautical Materials,Beijing Institute of Aeronautical Materials
摘 要：The purpose of this paper is to estimate the fatigue crack growth threshold of a high-Nb TiAl alloy at the different temperatures based on scanning electron microscopy（SEM）in-situ observation.The results indicated that the fatigue crack growth threshold ΔK th of a nearly lamellar high-Nb TiAl alloy with 8% Nb content at room temperature and 750 ℃ was determined as 12.89 MPa·m 1/2 and 8.69 MPa·m 1/2,respectively.The effect of the elevated temperature on the fatigue crack growth threshold cannot be ignored.At the same time,the early stage of fatigue crack propagation exhibited multicrack initiation and bridge-link behavior.
关键词：
