Control of Al content during ISM process of Nb3Al
来源期刊:中国有色金属学报(英文版)2000年第5期
论文作者:郭景杰 刘贵仲 苏彦庆 刘源 丁宏升 贾均
文章页码:571 - 575
Key words:Nb3Al alloy; induction skull melting; Al evaporation
Abstract: The activity coefficients of components in Nb3Al melt were calculated. On the basis of the activity coefficients, the evaporation behaviors, including the evaporation dynamic and the evaporation loss of Al in the Nb3Al melt during the induction skull melting (ISM) process were studied systematically. The results show that the evaporation-controlling mode of Al in the alloy melt is a double controlling mode, i.e. the diffusion of evaporation element in melt boundary layer and the evaporation reaction, under the conditions thatp=1.333 Pa and the scope of melt temperature is 2 235~2 635 K. When the melt temperature is 2385K(the superheat is 100K), the evaporation-controlling mode varies from the double controlling mode to a single controlling mode (the evaporation reaction on the surface of melt) if the vacuum chamber pressure is above 133 Pa.