• 제목/요약/키워드: prcipitates

검색결과 1건 처리시간 0.023초

Ni-Cr-Sn-Bi합금의 anti-galling 특성에 미치는 Te의 영향 (Effects of Te on the Anti-Galling Properties of Ni-Cr-Sn-Bi Alloy)

  • 하헌필;김경탁;심재동;김용규
    • 한국재료학회지
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    • 제15권1호
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    • pp.14-18
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    • 2005
  • Ni-Cr-Sn-Bi alloys were prepared by air melting and sand casting method and their anti-galling behaviors were examined. Anti-galling properties were dominantly influenced by Bi-rich low temperature precipitates. Alloying effects on the anti-galling properties were investigated for several alloying elements to improve anti-galling properties of the alloy. An alloy with $1-3wt\%$ of Te showed markedly improved anti-galling properties. Metallographic and tribological tests were carried out to find out reasons for excellent properties. It was found that Te containing alloy has finely distributed precipitates of Bi-rich phase. The addition of Te changed the morphology of the Ni-rich primary phase from globular to fine dendritic. As a result, the anti-galling phase precipitated between dendrite arms with fine distribution showed excellent anti-galling properties.