析出硬化微观机制及连续化模型

Precipitation hardening, a primary method for enhancing alloy strength, finds widespread applications in engineering alloys such as low-carbon steel and nickel-based alloys. Understanding precipitation hardening and developing corresponding theoretical models are crucial for the design of toughened alloys. Although early researchers devoted attention to precipitation hardening and developed classical precipitation hardening models based on the line tension theory, the misapplication of these models endures due to an insufficient grasp of the microscopic mechanisms underlying precipitation hardening. There are limited reviews that comprehensively unravel the interconnection between these hardening mechanisms within microphysical processes and offer guidance for the judicious selection of distinct precipitation hardening models. To bridge this gap, this study explores dislocation-precipitate interactions and analyzes the applicability of continuous precipitation hardening models, considering long- and short-range interactions. Additionally, the links between various strengthening concepts and dislocation shear or Orowan bypass mechanisms are investigated. Furthermore, we illuminate the transition of dominant interaction mechanisms with coherent precipitate sizes, from dislocation shear to Orowan bypass. This study significantly advances the understanding of precipitation hardening mechanisms, provides a precise description of their effects, and informs the design of alloys.