I wanted to know the approximate reasoning for the decrease in compressive strength of Fe based composite at high temperature (500 degree Celcius).It would be a kind gesture if some one provides me some of the papers related to the topic.
A clear exposition of the compression failure mechanisms is given, for example, in http://nptel.ac.in/courses/112104168/L29.pdf
At high temperatures, the Young's modulus of the matrix reduces significantly. This could justify a greater tendency to compression failure due to microbuckling of the fibers.
The iron which have some contents of Carbon inside its properties are varying due to change in the microstructure of this composite. When heat treatment of such alloys, distribution and shape of the carbon content does not remain the same, eventually causing the loss in the mechanical strength..