Background: Design against fatigue failure is very significant because a lot of failures in
engineering applications occur due to fatigue. Notches and holes are available almost in all
engineering applications. Crack initiation has a vital role in fatigue design because once crack initiates
it is very difficult to stop. This work is related with design against fatigue failure considering notch at
Methods: The experimental study shows the initiation of crack caused during fatigue of casting alloys.
It explains the crack initiation and fatigue strength of Aluminium alloy mineralized with silicon. By
using both mechanical and thermal loading; crack initiation at notch root as well as fatigue life have
been computed by means of single and two step loading. Phase life initiation has been reported by
applying load sequence effect using four-point rotating and bending fatigue testing machine. A
favourable working temperature and environment have been set up for the alloy used and experiments
have been performed on rotating and bending fatigue testing machine.
Results: The results from the experiments have been plotted in the form of S-N curves and comparison
has been conducted between crack initiation to failure at several mechanical loadings with and without
Conclusion: It has been concluded that mineralization affects during the case of both mechanical and
thermal loading. Logarithmic and power behaviour of material are obtained during two different cases.
Mathematical model for experimental data is also reported.