摘要
利用Miedema和Toop热力学模型计算粉末镍基合金中碳化物的生成热、活度系数及NbC、TiC碳化物的过剩Gibbs自由能,进一步求出合金中析出NbC、TiC碳化物的Gibbs自由能与温度的关系式,研究粉末镍基合金中碳化物的析出行为。结果表明,在实验温度范围内,合金中可析出NbC、TiC碳化物,并确定出合金中NbC、TiC碳化物相的析出温度分别为1353 K和1090 K,由于Ti、Nb晶体结构的相似性,碳化物中两原子可相互置换,并以(Ni,Ti)C型线性碳化物形式存在。
Precipitating behavior of NbC/TiC carbides in the nickel-based powder superalloy was investigated by means of Miedema and Toop thermodynamic models for calculating the forming heat,activity coefficient of carbides and surplus Gibbs free energy of NbC/TiC phases,and further putting forward the dependence of the Gibbs energy of precipitating carbides on temperatures.Results show that,in the ranges of experimental temperatures,the NbC/TiC carbides can be precipitated in the alloy,and the precipitating temperatures of NbC and TiC carbides are identified as 1353 K and 1090 K,respectively.The situations of the atoms Nb and Ti in the carbides may be exchanged each other due to the structure comparability of them,therefore,some carbides in the alloy are formed in the form of the（Ni,Ti）C compound phase.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2013年第7期187-192,共6页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金资助(51271125)
