纤维C-内标技术对TN₁₂M₁₀合金的SHS反应过程

来源期刊：中南大学学报(自然科学版)1997年第5期

论文作者：杨国涛 聂跃庄

文章页码：40 - 43

关键词：SHS 反应； 结晶； C 内标

Key words：SHS reaction； crystallization； C-internal standard method

摘    要：利用特殊的C-内标技术对TN₁₂M₁₀合金的SHS反应结晶过程进行了实验研究,发现包裹C-粒的包覆熔体(BFT)中含有杂质与合金元素;随着温度升高,Ca,Si,Fe,Ni的含量减少,直至消失,Ti,Mo含量则随之增加;BFT最后流到就近的Ti(Mo)C晶粒上结晶。因之,作者提出了TN₁₂M₁₀合金SHS反应结晶过程的顺序:(1)Ca,Si,Ni,Fe,Ti,Mo等杂质及合金元素随着加热温度的升高,依次先后熔化并随之被吸附于C-粒表面;(2)被吸附元素与C生成各自相应的亚稳定中间相,BFT正是由这些中间相组成的混合熔体;(3)BFT朝就近的燃烧波前处流动,使得包裹C-粒的BFT数量减少,上述熔体便继续包裹C-粒并形成新的BFT平衡数量;(4)当BFT中的C,Ti,Mo含量达到Ti(Mo)C的配比时,BFT就在近旁燃烧波前处的Ti(Mo)c晶粒表面结晶出新的Ti(Mo)C晶粒,最后完成SHS反应。文末讨论了A-K模型存在的问题。

Abstract: In this paper, an experimental study on process of TN₁₂M₁₀ alloy self-propogating high-temperature synthesis by using special Carbon Fibre internal standard method was discussed. It was found that: (1) Such impurities and alloy elements as Ca, Si, Fe, Ni, Ti, Mo were found in the clad melt (BFT) which contained C particles. (2) When temperature became higher and higher, Ca, Si, Fe, Ni contents in BFT decreased to zero and Ti, Mo contents increased. (3) BFT was not crystallized at the place of C particle where the A-K model had predicted it whould. It was crystallized at the Ti(Mo)C grain nearby. On the basis of experiments, the authors advanced a model for process of TN₁₂M₁₀ alloy SHS as follows: (1) When the temperature became higher and higher, Ca, Si, Fe impurities and Ni, Ti, Mo alloy elements were melted and adsorbed at the C particles surface one by one. (2) Metastable intermediate phases were produced from the adsorbed elements and Carbon. BFT was a mixture melt which was composed of these intermediate phases. (3) BFT flew to the combastion wavefront nearby and the temperature became higher rapidly. Each intermediate phase in BFt was disjointed at high temperature one by one according to their binding energy. The disjointed Ca, Si, Ni, Fe elements were vaporized and vanished from BFT one by one and C content in BFT increased. (4) When C, Ti Mo content in BFT was reached to the proportion of Ti(Mo)C, new Ti(Mo)C grain was crystallized at the old Ti(Mo)C grain surface near the combustion wavefront and SHS was finished. The problem of A-K model was discussed according to author's experiment. It was pointed out that the time resolution [1ms] of the X-ray diffractormeter in [1] was too low to get the correct process kinetic description of SHS which took place in 0.1 ms.