The effect of temperature and strain rate on the periodic cracking of amorphous AlxOy films on Cu

The high temperature properties of metal/ceramic interfaces play an important role in the operation of microprocessors and coated products. Determination of the interface properties over a range of testing conditions is critical in understanding and improving the performance of such systems. Periodic cracking of ceramic films on metal substrates provides a direct measure of the interface strength. A model AlxOy/Cu system is investigated over temperatures of 25–650 °C and at strain rates of 3.5 ⋅ 10− 2 s− 1 and 1.7 ⋅ 10− 5 s− 1. For this system it is found that temperature does not significantly affect the spacing of film cracks in the steady state, at a given strain rate. However, the high strain rate tests broaden the measured crack spacing distributions compared to the low strain rate tests. This broadening causes an increase in the average crack spacing at high strain rate. The minimum crack spacing was increased 15–20% by both increasing strain rate and increasing temperature.