Al/Fe 이종재의 마이크로 마찰교반 맞대기용접 적용성 평가

초록

In the automobile industry, there is an increasing demand for Al/Fe dissimilar metal joining. Friction stir welding (FSW) is an efficient solid-state welding method to achieve high-quality Al/Fe dissimilar metal welding. Here, we reviewed the previous studies on butt FSW of thin Al/Fe sheets and conducted feasibility tests to investigate the ap�plicability of micro FSW with a base material thickness of 1 mm or less. Most of the past literature, except for one study that adopted 1.12 mm-thick specimens, has worked with a base metal thickness of 1.5 mm or more. Selecting appropriate parameters can lead to a weld strength that is more than 90% of the base metal strength. Through feasi�bility tests on 2 mm-thick specimens, we could derive the welding conditions to obtain sound welds and the required joint strength. An adequate range (0.5-0.75 mm/rev) of advance per revolution was recommended to ensure the weld strength. A feasibility test on 1 mm-thick specimens revealed the possibility of melting of Al base metal during FSW of 1 mm-thin sheets; moreover, a low tool rotation speed was found to be crucial in ensuring the weld joint strength. The maximum weld strength for 1 mm-thick specimens was 200 MPa, which is 117% of the required weld strength.

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