Probabilistic rupture analysis of a brittle spray deposited Si–Al alloy under thermal gradient: Characterization and thermoelastic sizing guidelines

Abstract : The spray-deposited Si-Al CE9F alloy is a new material used for space applications involving temperature gradient. Thermal stresses arise and may affect the mechanical integrity of the components. It is therefore necessary to assess the critical temperature gradient to avoid failure. Hence this paper deals with the effect of temperature on the mechanical properties of the Si-Al CE9F alloy from-50°C to 130°C: Young's modulus, coefficient of thermal expansion and Weibull's parameters of the material to account for its brittle fracture behaviour through the Weibull's model. The experiments indicate a linear dependence of the Young's modulus with temperature and show that the coefficient of thermal expansion and the Weibull's parameters are almost constant in the temperature range [-50°C, 130°C]. From these results, an example of application schematizing a clamped plate under temperature gradient is studied to create abacus of probability of failure. These abacuses provide sizing guidelines and show the impact of the equivalent volume, highlighting the critical temperature gradients.