β型チタン合金のプラズマ電子ビーム溶解
1988 年 74 巻 2 号 p. 278-285
詳細
1988 年 74 巻 2 号 p. 278-285
The small-scale plasma electron beam melting method for β titanium alloys was investigated. The melting process was evaluated from the viewpoint of the yield of alloying elements in Ti-15Mo-2Fe-3Al and Ti-15V-3Cr-3Sn-3Al alloys and the segregation of the elements in the ingots.
The process consists of double meltings. Through the primary melting, a bar ingot was produced on a hearth. In the secondary melting of the bar ingot, solidified metal was continuously withdrawn downwards at a speed corresponding to the melting rate of the bar ingot.
The yield of alloying elements after secondary melting was from 86 to 90% in Al, 86% in Cr and 100% in the other elements such as Fe, Sn and V. The segregation in the bar ingot was recognized, but the segregation in the secondary ingot was not detectable except in the small zone finally solidified. The amounts of impurities such as C, N, O except H were the same as those in commercial alloys. The weight-loss of 14% was observed after the secondary melting. In conclusion, this process is convenient and available for melting of small-scale ingots of titanium alloy.
