Orowan strengthening with thermal activation

Abstract

Orowan strengthening is a primary way of strengthening metallic materials.The effect of temperature on the Orowan strengthening mechanism is still debatable in the present day.In this study,the effect of temperature on the Orowan strengthening mechanism is systematically investigated,a thermal activation Orowan strengthening mechanism is developed,and the corresponding Orowan stress is deduced.The results indicate that the obstacle scales substantially affect the thermal activation-based dislocation that bypasses the precipitates processes.In small obstacle scales,the thermal activation contribution to Orowan stress cannot be ignored;while in large obstacle scales,the thermal activation contribution can be ignored even at high temperatures.In addition to temperature, the effects of shear modulus,strain rate, and dislocation density are investigated on Orowan stress.This work not only provides new insight into the Orowan strengthening mechanism but also aids in the development of new high-temperature structural materials.