A.A. Atiyah; A. Al-Ghaban; M.A.N. Al-Keshwan
Abstract
The main goal of this work is to understanding the requirements to realize the synthesis of MAX phases in bulk form at high temperature. The phase stability of three different MAX phase ...
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The main goal of this work is to understanding the requirements to realize the synthesis of MAX phases in bulk form at high temperature. The phase stability of three different MAX phase systems Ti-Al-C,Cr-Al-C and V-Al-C has been investigated along this line. High purity powders were used as raw materials. They were mixed and then compacted under the pressure of 20 MPa. The compacted mixture was heated in an Ar atmosphere at a temperature range of (1000-1400) °C for (2-4) h. Finally, the sample was cooled down to room temperature. X-ray diffraction indicates that systems show a direct formation of MAX phase under these conditions. The SEM and optical microscopy results were used to confirm the structural features of the ternary phases and the less segregation or agglomeration. The results of sintering temperatures versus final density were discussed in terms of physical properties evaluation and hardness for indicate the mechanical properties. Finally, the differential scanning calorimetric results over the range of 25 to 650 ºC show that the reactions in all systems related directly to the Al melting point. It is obvious that the reactions in all these systems started at ~600 ºC that may support this attitude. It is expected to contribute towards a better basic understanding of this fascinating class of solids. Furthermore, we try to evaluate the here-proposed novel low temperature synthesis for other Mn+1AXn systems. This may release a new synthesis route for the mass production of materials with rather unique properties.
