| Title |
Effects of Mn , Cr and Co on the Thermal Expansion Behaviors of Fe - Ni Invar alloys |
| Authors |
이종현(J . H . Lee); 김희중(H . J . Kim); 강일구(I . K . Kang); 김학신(H . S . Kim); 안행근(H . G . Ahn) |
| Abstract |
The change of thermal expansion behavior by addition of Mn, Cr and Co within 5 wt% has been investigated to Fe-36% Ni Invar alloy. The amount of thermal expansion for the addition of Mn is larger than that far the addition of Cr. In the case of Co addition, thermal expansion decreases up to 4% Co but increases at 5% Co. The increase in the thermal expansion coefficient(α) per 1 wt% is 1.1×10^(-6) and 0.55×10^(-6) for the addition of Mn and Cr, respectively, in the temperature range of 30 to 100˚C. On the other hand the decrease in α for the addition of Co per 1 wt% up to 4% Co is 0.12×10^(-6) and then increases remarkably thereafter. The change of α with the kind and the amount of additives is discussed using some magnetic parameters. α decreases with increasing the ratio of specific magnetization to Curie temperature. In the range of the electron concentration(e/a) below 8.7, α for Mn or Cr added alloys increases with decreasing e/a but for Co added alloys the inverse tendency is shown. |