Thermodynamic Analysis of Ni-Al-WC System during Self-Propagating High Temperature Synthesis

2017 ◽  
Vol 898 ◽  
pp. 1569-1574
Author(s):  
Jian Jun Yuan ◽  
Xin Ying Liu ◽  
Dong Min Li ◽  
Shu Mei Lou
Keyword(s):  
High Temperature ◽  
Ternary System ◽  
Thermodynamic Analysis ◽  
Adiabatic Temperature ◽  
Temperature Synthesis ◽  
Thermodynamic Principle ◽  
High Temperature Synthesis ◽  
Preheating Temperature

Ni-Al-WC ternary system during self-propagating high-temperature synthesis (SHS) was analyzed and calculated based on thermodynamic principle, and the curves of adiabatic temperature (Tad) and preheating temperature (T0) and WC content (wt.%) were drawn. The results showed that adiabatic temperature of the system decreased with the increase of WC content and the maximum of WC content was about 34 wt.% for preheating temperature of 933K. Adiabatic temperature increased with increasing preheating temperature and properly increasing preheating temperature could promote the reaction self-sustaining when WC content was excessive and adiabatic temperature was less than 1912K.

Fabrication of cellular NiTi intermetallic compounds

2000 ◽  
Vol 15 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Bing-Yun Li ◽  
Li-Jian Rong ◽  
Yi-Yi Li ◽  
V. E. Gjunter
Keyword(s):  
High Temperature ◽  
Intermetallic Compounds ◽  
Open Porosity ◽  
Cellular Structure ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Preheating Temperature ◽  
Porosity Ratio

Self-propagating high-temperature synthesis (SHS) has been successfully developed for the fabrication of cellular NiTi intermetallic compounds, which have an open cellular structure with about 60 vol% porosity and more than 95% open-porosity ratio. The SHS reactions lead to the formation of TiNi, Ti2Ni, Ni3Ti, and Ni4Ti3 intermetallics. The SHS process can be controlled by regulating the preheating temperature, which has effects on the phase amount and the shape as well as macrodistribution of pores in the products.

Thermodynamic Evaluation for the Synthesis of T2 Phase from Elemental Powders via In Situ Reactively Hot-Pressing

2012 ◽  
Vol 538-541 ◽  
pp. 2082-2085
Author(s):  
Lai Qi Zhang ◽  
Lei Huang ◽  
Yong Ming Hou ◽  
Jun Pin Lin
Keyword(s):  
High Temperature ◽  
Hot Pressing ◽  
Initial Temperature ◽  
Adiabatic Temperature ◽  
Advanced Technology ◽  
Thermodynamic Evaluation ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Different Temperatures

T2 phase(Mo5SiB2) is a key component of the two Mo-Si-B tri-phase alloys under hot research. However, there is little research on T2 phase, especially its mechanic characteristics, due to the difficulty of fabrication of pure T2. In this present work, the thermodynamics of an advanced technology to fabricate pure T2 phase i.e. IRHP (In-situ Reactively Hot-Pressing) using elemental powders was analyzed. Formation free enthalpies at different temperatures for the compounds in Mo-Si-B system were calculated. Adiabatic temperatures and molten fractions of T2 phase at different initial temperatures for the reaction of synthesizing T2 phase were evaluated. The results show that it is feasible to in-situ synthesize T2 phase from elemental powders. T2 phase can not be synthesized using SHS(Self-propagating High-temperature Synthesis) mode of combustion. On the contrary, the explosion mode of combustion (IRHP) is receivable. Adiabatic temperature and molten fraction of T2 phase are relevant to initial temperature.

scholarly journals Theoretical Calculation of Self-Propagating High-Temperature Synthesis (SHS) Preparation of AlB12

2021 ◽  
Author(s):  
Chao Wang ◽  
Xiaoming Cao ◽  
Mengge Dong ◽  
Lu Zhang ◽  
Jianxing Liu ◽  
...  
Keyword(s):  
Free Energy ◽  
High Temperature ◽  
Theoretical Calculation ◽  
Gibbs Free Energy ◽  
Theoretical Calculations ◽  
Adiabatic Temperature ◽  
Raw Material ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Calculation Results

Although experimental results of preparing AlB12 by self-propagating high-temperature synthesis using Mg-B2O3-Al2O3 as raw material has been studied, the theoretical calculations for the preparation of AlB12 have not been examined as thoroughly. In this article, for the first time, we report on the study of theoretical calculation and the adiabatic temperature, calculated, and compared with the actual reaction temperature. The Gibbs free energy for each level of reaction is also calculated. The calculation results show that the adiabatic temperature is 2789.5 K, the standard Gibbs free energy of each reaction is less than 0, and the reaction can proceed spontaneously, which is consistent with the results of the experiment. <br>

Preparation of ZrC Powder by Self-Propagating High-Temperature Synthesis

2009 ◽  
Vol 66 ◽  
pp. 258-261 ◽  
Author(s):  
Jing Li ◽  
Zheng Yi Fu ◽  
Jin Yong Zhang ◽  
Hao Wang ◽  
Wei Min Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Exothermic Reaction ◽  
Fine Powder ◽  
Adiabatic Temperature ◽  
Electron Micrograph ◽  
Scanning Electron Micrograph ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Average Size ◽  
Scanning Electron

ZrC fine powder has been prepared by self-propagating high-temperature synthesis (SHS) using exothermic reaction of ZrO2-C-Mg system. By theoretical calculating, the adiabatic temperature (Tad) for the system is about 2235K enough to react as SHS process. The Tad observed during experiment is 1850K. The results show that high pure ZrC powder is obtained with appropriate Mg contents. The scanning electron micrograph shows that the average size of ZrC particles is about 2μm.

scholarly journals Theoretical Calculation of Self-Propagating High-Temperature Synthesis (SHS) Preparation of AlB12

2021 ◽  
Author(s):  
Chao Wang ◽  
Xiaoming Cao ◽  
Mengge Dong ◽  
Lu Zhang ◽  
Jianxing Liu ◽  
...  
Keyword(s):  
Free Energy ◽  
High Temperature ◽  
Theoretical Calculation ◽  
Gibbs Free Energy ◽  
Theoretical Calculations ◽  
Adiabatic Temperature ◽  
Raw Material ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Calculation Results

Although experimental results of preparing AlB12 by self-propagating high-temperature synthesis using Mg-B2O3-Al2O3 as raw material has been studied, the theoretical calculations for the preparation of AlB12 have not been examined as thoroughly. In this article, for the first time, we report on the study of theoretical calculation and the adiabatic temperature, calculated, and compared with the actual reaction temperature. The Gibbs free energy for each level of reaction is also calculated. The calculation results show that the adiabatic temperature is 2789.5 K, the standard Gibbs free energy of each reaction is less than 0, and the reaction can proceed spontaneously, which is consistent with the results of the experiment. <br>

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