C-Ni and Al-C-Ni phase diagrams and thermodynamic properties of C in the alloys from 1550 °C to 2300 °C

The C-Ni and Al-C-Ni phase diagrams were determined by chemical analysis of alloys saturated with carbon within sealed graphite crucibles. The solubility of carbon in nickel over the temperature range 1550 °C to 2300 °C is given by log (at. pct C)=2.0376−1874.68/T, where T is temperature in kelvin. Isothermal sections for the ternary system were determined at intervals of 150 °C over the range of temperatures investigated. The univariant points on the 1700 °C, 1850 °C, and 2000 °C isotherms were determined by metallographic examination of rapidly cooled alloys to be about 67.2Al-1.1C-31.7Ni, 70.3Al-2.3C-27.4Ni, and 82.5Al-7.0C-10.5Ni, respectively, where all concentrations are in atomic percent. Graphite, Al4C3 (decomposition temperature 2156 °C), and AlNi (decomposition temperature 1638 °C) were the only solid phases observed within the temperature range investigated. The excess partial Gibbs energy for dissolved C, % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfKttLearuqr1ngBPrgarmWu51MyVXgatC% vAUfeBSjuyZL2yd9gzLbvyNv2CaeHbd9wDYLwzYbItLDharyavP1wz% ZbItLDhis9wBH5garqqtubsr4rNCHbGeaGqiVu0Je9sqqrpepC0xbb% L8F4rqqrFfpeea0xe9Lq-Jc9vqaqpepm0xbba9pwe9Q8fs0-yqaqpe% pae9pg0FirpepeKkFr0xfr-xfr-xb9adbaqaaeGaciGaaiaabeqaam% aaeaqbaaGcbaGafm4raCKbaebadaqhaaWcbaaceaGaa8NmaaqaaGab% ciaa+vgaaaaaaa!3DD9! $$\bar G_2^e $$ , in liquid Al-C-Ni solutions in equilibrium with C, as calculated from the experimental solubilities and thermodynamic data on Al-Ni, is % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfKttLearuqr1ngBPrgarmWu51MyVXgatC% vAUfeBSjuyZL2yd9gzLbvyNv2CaeHbd9wDYLwzYbItLDharyavP1wz% ZbItLDhis9wBH5garqqtubsr4rNCHbGeaGqiVu0Je9sqqrpepC0xbb% L8F4rqqrFfpeea0xe9Lq-Jc9vqaqpepm0xbba9pwe9Q8fs0-yqaqpe% pae9pg0FirpepeKkFr0xfr-xfr-xb9adbaqaaeGaciGaaiaabeqaam% aaeaqbaaGceaqabeaacuWGhbWrgaqeamaaDaaaleaaiqaacaWFYaaa% baaceiGaa4xzaaaakiabg2da9iabgkHiTiaa-jfacqWGubavcqGHGa% aicaWFjbGaa8NBaiaa-bcacaGF5bGaa4xpaiaa-fdacaWFZaGaa8Nn% aiaa-XcacaWFGaGaa8Nmaiaa-LdacaWFWaGaeyOeI0Iaa8xnaiaa-D% dacaWFUaGaa8xoaiaa-HdacaGFubGaa4hiaiaa+TcacaGFGaGaa83m% aiaa-5cacaWFWaGaa4hvaiaa+bcacaWFjbGaa8NBaiaa-bcacaGFub% Gaa4hiaiaa+TcacaGFGaGaa4hEamaaCaaaleqabaGaa8Nmaaaakiaa% -HcacqGHsislcaWF2aGaa83maiaa-XcacaWFGaGaa8xmaiaa-Ddaca% WFWaGaa8hiaiaa-TcacaWFGaGaa8xmaiaa-rdacaWFUaGaa8hnaiaa% -bcacaGFubGaa8xkaaqaaiacacibcaaa-TcacGaGasGaaaWFGaGaia% iGeiaaa4NEamacacibcaaaCaaaleqcacibcaaabGaGasGaaaGaiaiG% eiaaa8Nmaaaakiacacibcaaa-HcacWaGasGaaaGHsislcGaGasGaaa% WFXaGaiaiGeiaaa8hmaiacacibcaaa-rdacGaGasGaaaWFSaGaiaiG% eiaaa83naiacacibcaaa-fdacGaGasGaaaWF2aGaiaiGeiaaa8hiai% acacibcaaa-TcacGaGasGaaaWFGaGaiaiGeiaaa83maiacacibcaaa% -fdacGaGasGaaaWFUaGaiaiGeiaaa83naiacacibcaaa-zdacGaGas% GaaaGFubGaiaiGeiaaa8xkaiacacibcaaa-bcacGaGasGaaaWFRaGa% iaiGeiaaa8hiaiacacibcaaa+HhacGaGasGaaaGF6bGaiaiGeiaaa8% 3waiadacibcaaagkHiTiacacibcaaa-jdacGaGasGaaaWFZaGaiaiG% eiaaa8hlaiacacibcaaa-ndacGaGasGaaaWFYaGaiaiGeiaaa8Nnai% acacibcaaa-bcacGaGasGaaaWFRaGaiaiGeiaaa8hiaiacacibcaaa% -jdacGaGasGaaaWFWaGaiaiGeiaaa8Nlaiacacibcaaa-HdacGaGas% GaaaWFYaGaiaiGeiaaa4hvaiacacibcaaa+bcacGaGasGaaaGFRaGa% iaiGeiaaa4hiaiacacibcaaa+HhacGaGasGaaaGFGaGaiaiGeiaaa8% hkaiadacibcaaagkHiTiacacibcaaa-ndacGaGasGaaaWF3aGaiaiG% eiaaa8hlaiacacibcaaa-bcacGaGasGaaaWFWaGaiaiGeiaaa8hnai% acacibcaaa-bdaaeaacGaGacHaaaWFRaGaiaiGqiaaa8hiaiacacie% caaa-fdacGaGacHaaaWF3aGaiaiGqiaaa8Nlaiacaciecaaa-jdacG% aGacHaaaWFYaGaiaiGqiaaa4hvaiacaciecaaa-LcacGaGacHaaaWF% GaGaiaiGqiaaa83kaiacaciecaaa-bcacGaGacHaaaGF4bGaiaiGqi% aaa4NEaiacaciecaaa+bcacGaGacHaaaWFOaGaiaiGqiaaa83naiac% aciecaaa-rdacGaGacHaaaWF3aGaiaiGqiaaa8hlaiacaciecaaa-n% dacGaGacHaaaWF5aGaiaiGqiaaa8hmaiacaciecaaa-bcacWaGacHa% aaGHsislcGaGacHaaaWFYaGaiaiGqiaaa8hmaiacaciecaaa-jdacG% aGacHaaaWFUaGaiaiGqiaaa8hmaiacaciecaaa-jdacGaGacHaaaGF% ubGaiaiGqiaaa8hiaiacaciecaaa-Lcaaaaa!14FE! $$\begin{gathered} \bar G_2^e = - RT In y = 136, 290 - 57.98T + 3.0T In T + x^2 ( - 63, 170 + 14.4 T) \hfill \\ + z^2 ( - 104,716 + 31.76T) + xz[ - 23,326 + 20.82T + x ( - 37, 040 \hfill \\ + 17.22T) + xz (747,390 - 202.02T ) \hfill \\ \end{gathered} $$ where R is the gas constant and x, y, and z are the atomic fractions of Al, C, and Ni, respectively. The equations for % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfKttLearuqr1ngBPrgarmWu51MyVXgatC% vAUfeBSjuyZL2yd9gzLbvyNv2CaeHbd9wDYLwzYbItLDharyavP1wz% ZbItLDhis9wBH5garqqtubsr4rNCHbGeaGqiVu0Je9sqqrpepC0xbb% L8F4rqqrFfpeea0xe9Lq-Jc9vqaqpepm0xbba9pwe9Q8fs0-yqaqpe% pae9pg0FirpepeKkFr0xfr-xfr-xb9adbaqaaeGaciGaaiaabeqaam% aaeaqbaaGcbaGafm4raCKbaebadaqhaaWcbaaceaGaa8NmaaqaaGab% ciaa+vgaaaaaaa!3DD9! $$\bar G_2^e $$ for C in equilibrium with Al4C3 have also been obtained for the binary and ternary alloys.