激光辅助滚压GH4169微观组织研究

Study of the microstructure of laser-assisted burnishing GH4169

  • 摘要: 镍基合金(GH4169)加工过程中的梯度晶粒以及晶界结构等微观组织是影响材料力学性能与服役寿命的关键因素,如何提高材料力学性能需要深入解析,在传统光整加工滚压基础上引入原位热辅助以降低材料变形抗力实现对金属材料表面微观组织与性能的精准调控。本研究通过建立元胞自动机(cellular automata, CA)模型,构建了GH4169在传统滚压与激光辅助滚压工艺下的微观组织演变仿真框架,综合考虑了应变率、温度场及动态再结晶(dynamic recrystallization, DRX)动力学,通过对比不同工艺下晶粒尺寸、晶界分布等,揭示了激光能量输入对塑性变形区微观组织的调控规律,结果表明,激光辅助滚压通过热-力耦合效应,促进了动态再结晶,并对晶粒细化层进行实验论证预测误差均小于5%。

     

    Abstract: The microstructure of nickel-based alloys (GH4169) which including grain gradients and grain boundary structures is a key factor influencing the mechanical properties and service life during processing of the material during processing. It is an in-depth analysis that required to enhance the mechanical properties of material. By introducing in-situ thermal assistance to the conventional finishing burnishing process to reduce the deformation resistance of material, precise control over the microstructure and properties of the metal surface can be achieved. In this study, a cellular automaton (CA) model is established to construct a simulation framework which comprehensively accounts for strain rate, temperature fields, and dynamic recrystallization (DRX) kinetics for the microstructural evolution of GH4169 that is applied to the conventional burnishing and laser-assisted burnishing processes. By comparing grain size, grain boundary distribution and other factors under different processes, this study reveals the regulatory mechanisms of laser energy input on the microstructure within the plastic deformation zone. The results indicate that laser-assisted burnishing promotes dynamic recrystallization through thermo-mechanical coupling effects. Experimental validation of the predicted grain refinement layer showed prediction errors of less than 5%.

     

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