In-situ SEM fatigue testing for investigating crack propagation of Al alloy thin films

Abstract

This paper describes an experimental technique for evaluating fatigue crack propagation behavior in-situ scanning electron microscope (SEM) observation. Pure Al and Al-Si alloy thin films deposited by sputtering were subjected to fatigue test. Specially developed compact tensile test equipment was used for the test in a SEM. A fatigue crack initiated at the sidewall of a specimen, and propagated along slip lines first. Then, the propagation direction changed to another direction, across to slip lines, which was caused by Si precipitation. Consequently, Al-Si alloy thin film showed longer lifetime than pure Al thin film.