1 23 Journal of Materials Engineering and Performance ISSN 1059-9495 J. of Materi Eng and Perform DOI 10.1007/s11665-011-0071-5 Effect of MgO and CaO on Transformation of Andalusite to Mullite H. Pooladvand, S. Baghshahi, B. Mirhadi, A. R. Souri & H. Arabi