Stainless steel reveals an anomaly in thermal expansion behavior of severely deformed materials

Thermal expansion of materials is fundamental practical relevance and arises from an interplay several material properties. For nanocrystalline materials, accurate measurements thermal based on high-precision reference dilatometry allow inferring phenomena taking place at internal interfaces such as vacancy annihilation grain boundaries. Here we report obtained for a severely deformed 316L austenitic steel, showing anomaly in difference curves which attribute to the exceptionally high density stacking faults. On basis ab intio simulations evidence that peculiar magnetic state steel causes faults expand more than matrix. So far, effect has only been observed this particular but expect other could exhibit even pronounced anomaly.