50Ni-Fe合金の磁性および減圧下での精製効果におよぼすSi添加の影響

Abstract

It can be presumed thermodynamically that Si forms a stable gaseous monoxide and increases the refining effect under vacuum in a way consistent with Ge, and the addition of Si should be also thought to be effective for improvement of the magnetic properties of Fe-Ni alloys because of decreasing the gas content and non-metallic inclusions. In the present paper, on the basis of the above prediction, effect of a small amounts of Si addition to 50Ni-Fe alloys was investigated thermodynamically and magnetically. The results obtained are summarized as follows: (1) It is theoretically induced that Si becomes more easily to form a gaseous monoxide under vacuum and its vapor pressure attains about 102 mmHg at 1600°C. And it is presumable therefore that Si is useful as an refining agent similar to Ge. The reults of gas analysis are comparable with the curve of the theoretical calculation as PSiO=5 mmHg. (2) The addition of Si induces a remarkable decrease in coercive force and a remarkable increase in initial permeability. The maximum permeability is the highest near 1%Si, and the effective permeability becomes larger in high frequency because of high resistivity by the addition of Si. (3) The addition of Si, as well as Ge, promotes remarkably the grain growth, which is particularly effective in the initial addition of only a few %Si. The grain size dependence of the coercive force and the initial permeability are respectively expressed by the following equations:(This article is not displayable. Please see full text pdf.) \ oindentThe above relations are always seen no matter what amounts of Si are added.