• 제목/요약/키워드: Super-rapidly cooled alloy films

검색결과 1건 처리시간 0.013초

진공증착법으로 제작한 Ag-X(X=Cu,Ni,C) 합금의 기계적 성질에 관한 연구 (A Study on the Mechanical Properties of Ag-X(X=Cu,Ni,C) Alloys Prepared by the Vacuum-deposition Technique)

  • 오창섭;한창석
    • 열처리공학회지
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    • 제24권5호
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    • pp.243-250
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    • 2011
  • When alloys are vacuum-deposited on cooled substrates, super-rapidly cooled alloy films in the unequilibrium state can be obtained. As an application of this method, Ag-Cu, Ag-Ni and Ag-C alloys were successfully produced, and their mechanical properties with tempering temperature were investigated. The following results were obtained : (1) In case of Ag-Cu alloys, the solid solution was hardened by tempering at $150^{\circ}C$. The hardening is considered to occur when the solid solution begins to decompose into ${\alpha}$ and ${\beta}$ phases. The Knoop hardness number of a 40 at.%Ag-Cu alloy film deposited on a cooled glass substrate was 390 $kg/mm^2$. The as-deposited films were generally very hard but fractured under stresses below their elastic limits. (2) In case of Ag-Ni and Ag-C alloys, after the tempering of 4 at.%Ni-Ag alloy at $400^{\circ}C$ and of 1 and 2 at.%C-Ag alloys at $200^{\circ}C$, they were hardened by the precipitation of fine nickel and carbon particles. The linear relationship between proof stress vs. $(grain\;diameter)^{-l/2}$ for bulk silver polycrystals can be applied to vacuum-deposited films up to about 0.1 ${\mu}m$ grain diameter, but the proof stress of ultra-fine grained silver with grain diameters of less than 0.1 ${\mu}m$ was smaller than the value expected from the Petch's relation.