Microstructure and fatigue properties of linear friction welded TC4 titanium alloy joints |
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| Authors: | S Q Wang W Y Li G D Wen D L Chen |
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| Affiliation: | 1. School of Materials Science and Engineering, Xi’an Shiyou University, Xi’an 710065, Shaanxi, PR China;2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, Shaanxi, PR China;3. Xi’an Research Institute of China Coal Technology &4. Engineering Group, Xi’an 710077, Shaanxi, PR China;5. Department of Mechanical and Industrial Engineering, Ryerson University, Toronto M5B 2K3, Ontario, Canada |
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| Abstract: | The welded joints are often subjected to cyclic stresses and high-strain-rate deformation resulting in worrisome fatigue failure. Therefore, it is necessary to evaluate the fatigue resistance and cyclic deformation characteristics of these weldments. Ti–6Al–4V–0.3Fe–0.1C–0.05N–0.015H–0.2O (TC4) titanium alloy joints were produced via linear friction welding and a sound joint was obtained. It was observed that fine subgrains formed in the weld zone where the hardness became higher. The strain ratio had a strong effect on the cyclic deformation characteristics of the joint, with hysteresis loops being different at different strain ratios. However, the difference of fatigue life of the joint was small with varying strain ratios. The stress amplitude of linear friction welded TC4 joint showed essentially cyclic softening until failure at all strain ratios. Fatigue cracks initiated from the near-surface of base metal and propagated by the formation of fatigue striations together with secondary cracks. |
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| Keywords: | Titanium alloy Microstructure Linear friction welding Fatigue Cyclic deformation |
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