Intergranular Fatigue Cracking Mechanisms
Author(s): ZHANG Zhefeng, WANG Zhongguang, SHI Changxu
Pages: 270-275
Year: 2004 Issue: 2
Journal: JOURNAL OF THE GRADUATE SCHOOL OF THE CHINESE ACADEMY OF SCIENCES
Keyword: grain boundary; fatigue crack; persistent slip bands; pile-up of dislocations;
Abstract: Intergranular fatigue cracking mechanisms of copper crystals containing various grain boundaries (GBs) were investigated by electron channeling contrast(ECC) technique in scanning electron microscope (SEM). Evidence by direct observations indicates that fatigue cracking always nucleated along various random large-angle GBs due to impingement of persistent slip bands (PSBs) and pile-up of dislocations. However, low-angle GBs do not produce fatigue cracks because the dislocations can be transferred through the GBs by PSBs. It is suggested that intergranular fatigue cracking strongly depends on the interaction mode of PSBs with GBs, while the GB structure itself plays a much less role.
Pages: 270-275
Year: 2004 Issue: 2
Journal: JOURNAL OF THE GRADUATE SCHOOL OF THE CHINESE ACADEMY OF SCIENCES
Keyword: grain boundary; fatigue crack; persistent slip bands; pile-up of dislocations;
Abstract: Intergranular fatigue cracking mechanisms of copper crystals containing various grain boundaries (GBs) were investigated by electron channeling contrast(ECC) technique in scanning electron microscope (SEM). Evidence by direct observations indicates that fatigue cracking always nucleated along various random large-angle GBs due to impingement of persistent slip bands (PSBs) and pile-up of dislocations. However, low-angle GBs do not produce fatigue cracks because the dislocations can be transferred through the GBs by PSBs. It is suggested that intergranular fatigue cracking strongly depends on the interaction mode of PSBs with GBs, while the GB structure itself plays a much less role.
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