| In the magnetic alloy which consists of three principal elements, namely iron, carbon and aluminum, the effect of chemical composition, pre-heated metallic mold temp, and tempering temperature on residual induction and hardness were studied for the simple ternary alloys. In addition to the above, the effect of Mn and Si as the impurity, and Co and Ni as the additional element on residual induction were studied too. The optimum conditions for casting into pre-heated metallic mold are as follows. (1) chemical composition; C＝2.0∼2.1% Al＝7.5∼7.8% (2) pre-heated mold : 150℃ (3) tempering temp : 350℃ (4) structure : β-martensite＋austenite (little) and this residual induction is similar to the alloy quenched after solid solution treatment. In other words, the chilled effect is same as quenched state in Fe-Al-C type permanent magnet under above chemical composition. |
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