• Journal of Welding and Joining
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• 제14권4호
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• pp.53-61
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• 1996

It was attempted to improve the wear resistance of Al alloy under the load condition by making a formation of the thicker surface hardening alloy layers. The thicker surface hardening alloy layers were formed on 6061 Al alloys overlayed by MIG and TIG welding process with Cu powders feeding. The characteristics of hardening and wear resistance have been investigated in relation to the microstructures of alloyed layers, with a selection of optimum alloying conditions for formation of overlaying layer. The results obtained were summarized as follows With increasing feeding rate of Cu powders by MIG welding, the hardness and specific wear of the overlay weld alloys were increased. It is considered that these high hardness and specific wear of overlay weld alloys were due to the formation of Θ($Al_2Cu$) phases. With increasing feeding rate of Cu powders by TIG welding, the hardness and specific wear of the overlay weld alloys were increased in feeding rates 12 and 18g/min. However, the hardness and specific wear were decreased in the powder feeding rate 38g/min. It is considered that considered that decrease of hardness and specific wear in the powder feeding rate 38g/min due to formation of ${\gamma}$($Al_4Cu_9$) phases.

• Journal of Advanced Marine Engineering and Technology
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• 제37권1호
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• pp.29-34
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• 2013

용접과정 중에 용접부가 공기에 노출되면 용접성능을 약화시킨다. 불활성가스 텅스텐 아크용접(GTAW)법을 사용하여 티타늄 용접을 하는 경우 용접부가 자주/적색, 청색, 노란색, 회색, 흰색 등의 빛깔을 보이면 이는 용접 시 공기 중의 산소와 질소에 오염된 것을 의미한다. 따라서 용접부를 대기로부터 보호하기 위한 방법으로 실딩 가스를 사용한다. 이것은 대기에 의한 오염을 방지할 뿐만 아니라 용착부와 열영향부도 상온까지 냉각될 때까지 대기로부터 차단시킨다. 본 연구에서는 Trailing Shielding Jig 의 모양과 형태 그리고 토치보호($13{\sim}20{\ell}/min$), 후방보호($22{\sim}30{\ell}/min$), 이면보호($25{\sim}30{\ell}/min$)등 건전한 용접부에 적합한 실딩 가스에 대한 결과를 도출하였다.