Orowan strengthening with thermal activation

TL;DR

This paper systematically investigates how temperature influences the Orowan strengthening mechanism in metals, developing a thermal activation model that accounts for obstacle size, shear modulus, strain rate, and dislocation density effects.

Contribution

It introduces a thermal activation-based Orowan strengthening model and analyzes the impact of various factors on Orowan stress at different temperatures.

Findings

Thermal activation significantly affects Orowan stress in small obstacle scales.

In large obstacle scales, thermal activation effects are negligible even at high temperatures.

Temperature, shear modulus, strain rate, and dislocation density all influence Orowan strengthening.

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.