• Title/Summary/Keyword: 워터캐비테이션피닝

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Effects of Water Cavitation Peening on Cavitation Characteristics of 5000 Series Al Alloys (5000계열 Al 합금의 캐비테이션 특성에 관한 워터 캐비테이션 피닝의 영향)

  • Kim, Seong-Jong;Hyun, Koang-Yong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.5
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    • pp.481-487
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    • 2012
  • Recently, the construction of the small Al alloy ships is an increasing trend in viewpoint such as the disposal issue of a retired ship, the enhancement of environmental regulation and resources recycling etc. for FRP ships. However, Al alloy ship which can achieve high speed by light weight in marine environment is exposed to a problem on materials damage by cavitation-erosion which is generated by large impact pressure with the collapse of air bubbles due to cavitation. Consequently, in this study, water cavitation peening technology was applied in Al alloy for ship to enhance durability life by preventing cavitation damage. So, the water cavitaton peening application time that presented the excellent cavitation characteristic investigated. The weight-loss of 5456-H116, 5083-H321 and 5052-O Al alloy at the optimum water cavitation peening time were improved to 42.11 %, 50.0 % and 25.7 %, respectively.

Electrochmical Characteristics by Water Cavitation Peening of Cu Alloy (워터캐비테이션피닝된 동합금의 전기화학적 특성평가)

  • Kim, Seong-Jong;Han, Min-Su;Kim, Min-Sung
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.8
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    • pp.1083-1090
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    • 2012
  • Copper alloys are widely used for casting materials including ship's propellers and pump impellers as they provide high corrosion resistance. In addition, the demand for these alloys is increasing with rapid growth of offshore structures and exploitation of various substitute energy sources. However, they require regular maintenance because of erosion and cavitation damages induced by exposure to marine environment at high speed flows for a long period of time. Water cavitation peening have received attention as one of surface modifications for durability improvement of the copper alloys. This is a environment friendly technology without influence of heat and easily applicable to casting materials. In this research, water cavitation peening was employed in distilled water for copper alloy castings as a function of time and evaluation of corrosion resistance was followed in seawater for the modified surface by using electrochemical methods. The result suggests that the water cavitation peening for 2 minutes was found to be the optimal peening parameter in terms of durability and corrosion resistance.