 The thermal expansion coefficients of T15 MOSI alloys were measured by dilatometry during heating and cooling cycles. The results showed that the presence of silicon reduced the beta-transist temperature and transformed the alloy into the omega phase. Additionally, the thermal expansion coefficient curves had an S-shaped pattern, indicating a transformation from the beta phase to the omega phase. This article was authored by Hayyam A. Ali, Mohammed M. L. Syed Seelman, Ashraf Butkar, and others.