Ni-Ti-Si三元合金热力学性质及非晶形成范围计算  

Thermodynamic Properties of Ni-Ti-Si Ternary Alloy and Calculation of Amorphous Formation Range

作　　者：董洪娜 李桂杰[1] DONG Hongna;LI Guijie(School of Materials Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]山东科技大学材料科学与工程学院,山东青岛266590

出　　处：《材料开发与应用》2024年第3期10-19,共10页Development and Application of Materials

摘　　要：基于Chou模型计算了在1273 K下Ni-Ti-Si三元合金的形成焓ΔH、过剩熵S^(E)、过剩吉布斯自由能G^(E)、各组元的活度以及8个Ni-Ti-Si三元合金金属间化合物的形成焓。基于Toop模型预测了在1273 K下Ni-Ti-Si三元合金的非晶形成范围。结果表明:Ni-Ti-Si三元合金在x_(Ni)=0.39、x_(Ti)=0.25、x_(Si)=0.36时的ΔH、S^(E)、G^(E)取得最小值,分别为ΔH_(min)=-56.25 kJ/mol、SE_(min)=-6.38 J/mol、GEmin=-48.14 kJ/mol。8个金属间化合物中,金属间化合物τ_(1)的ΔH最负,这说明τ1的相稳定性最高,在凝固时最先析出,然后是τ_(2)、τ_(6)、τ_(8)析出,最后是τ_(3)、τ_(4)、τ_(5)析出;Ni-Ti-Si三元系各组元活度值与理想熔体之间存在非常大的负偏差;Ni-Ti-Si三元合金可以形成非晶,并且非晶形成范围很大,主要位于x_(Ti)=20%~80%和x_(Ni)=15%~90%的成分范围内。本研究计算出的Ni-Ti-Si三元合金的金属间化合物成分范围以及非晶形成范围均与实验结果吻合良好。The formation enthalpy ΔH,excess entropy S^(E),excess Gibbs free energy G^(E),and activity of each constituent element of Ni-Ti-Si ternary alloy at 1273 K is calculated based on Chou model,and the formation enthalpies of 8 intermetallic compounds of the Ni-Ti-Si ternary alloy are calculated.The amorphous formation range of Ni-Ti-Si ternary alloy at 1273 K is predicted based on Toop model.The calculated results show that when xNi=0.39,xTi=0.25,and xSi=0.36,the Ni-Ti-Si ternary alloy has the minimumΔH,SE and GE,and ΔH_(min)=-56.25 kJ/mol,SE_(min)=-6.38 J/mol,and GE_(min)=-48.14 kJ/mol.Of the 8 intermetallic compounds,the ΔH of the intermetallic compound τ_(1) is the most negative,indicating that its phase stability is the highest.It is the first to precipitate,τ_(2),τ_(6),τ_(7) and τ_(8) are the next,and τ_(3),τ_(4) and τ_(5) are the last.Ni-Ti-Si ternary system has a very large negative deviation between the activity values of each constituent element and the ideal melt.Amorphous can be formed in the Ni-Ti-Si ternary alloy,and the amorphous formation range is very large,mainly in the composition range of x_(Ti)=20%~80% and x_(Ni)=15%~90%.The calculated range of intermetallic compounds and amorphous formation range of Ni-Ti-Si ternary alloy are in good agreement with the experimental results.

关 键 词：Chou模型 Toop模型 形成焓 过剩熵 过剩吉布斯自由能 活度 

分 类 号：TG142.74[一般工业技术—材料科学与工程]