Effect of heat treatment on fatigue behaviour of stir-cast EV31A magnesium alloy

[Display omitted] •The stir casting process is used to prepare the EV31A Magnesium alloy.•The heat treatment process (T4 and T6 format) influences the fatigue performance.•Fractography reveals the transgranular fracture in the fatigue test specimen. The primary goal of this research is to investigate the fatigue properties of EV31A magnesium alloy under as-cast, T4, and T6 heat-treated conditions. The fatigue testing is carried out at an ambient temperature of 21–25 °C, with a stress ratio and frequency of 0.1 and 15 Hz, respectively. The linear intercept method is used to determine the grain size of the alloy under consideration. At a fatigue strength of 78.1 MPa, the as-cast must have a fatigue life of 1.6 × 105 cycles. T6 heat-treated sample has a 21% increase in fatigue compared to T4. The Transmission Electron Microscopy (TEM) method is useful for assessing the SAED pattern and interpreting precipitate morphology. The fractography reveals that the porosity of the stir-cast sample causes crack initiation, and the EV31A alloy fails in a transgranular mode.