Details

Autor(en) / Beteiligte

• Zaki, Z.I.
• Mostafa, Nasser Y.
• Ahmed, Y.M.Z.

Titel

Synthesis of dense mullite/MoSi2 composite for high temperature applications

Ist Teil von

• International journal of refractory metals & hard materials, 2014-07, Vol.45, p.23-30

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2014

Quelle

Elsevier ScienceDirect Journals

Beschreibungen/Notizen

• This work is aimed at producing a dense mullite/MoSi2 composite from a reactive blend of MoO3, SiO2 and Al by under load-combustion synthesis. Thermodynamic analyses proved the development of the entire combustion product in molten state with an adiabatic temperature of 2340K. Diluting the reaction mixture with 25vol.% of the combustion product was necessary to produce homogeneity between the obtained phases. The sample porosity was reduced to ~3.0vol.% by controlling the pressing load, Al particle size and the delay time. The coefficient of thermal expansion of the obtained product was 5.96–8.93×10−6K−1. The obtained dense composite exhibited good oxidation resistance at 1300°C and a low electrical resistivity (1.80Ω·cm). [Display omitted] •To the best of our knowledge this composite was not produced in a dense form before.•Also this work includes the conduction of the endothermic reaction between alumina and silica in a self-sustaining manner.•The factors affecting the in situ synthesis and consolidation of mullite/MoSi2 composite are presented in a systematic study.•A complete thermodynamic study of the main reaction is presented.•The obtained product has a high density with less than 3vol.% porosity and low resistivity (1.8Ω) at room temperature.