Creep property evaluation of light alloys by means of the Small Punch test: Creep master curves

摘要

The low-density values of light alloys have made them ideal candidates for reducing the weight of structural components. Given their relatively low melting points, it is vital to characterise the behaviour of these materials at high temperature working conditions. In this paper, the Small Punch Creep (SPC) testing technique is applied to evaluate the creep properties of AlSi9Cu3 and AZ31 alloys, which respectively exhibit brittle and ductile fractures. By comparing the SPC results with the uniaxial ones, a relationship between miniature and conventional tests has been established. Three different approaches have been employed, by comparing tests which share (ⅰ) the same time to rupture, (ⅱ) the Larson-Miller and (ⅲ) the Orr-Sherby-Dorn parameter. Regardless of the behaviour of the material, the applied methods lead to the same relationships, proving their accuracy. Furthermore, the SPC tests have been used to obtain creep master curves and the usual creep engineering parameters, which are in good agreement with those obtained by means of conventional methods, confirming the suitability of the SPC technique for this purpose.