多向锻造工艺最优温度设计：晶体相场研究

Designing Optimal Temperature for Multi-directional Forging Process: A Phase-Field Crystal Study

摘要:

以多向锻造温度为自变量，采用双模晶体相场模型，研究了不同温度下的形核模式、反应机制及晶界-位错相互作用。结果表明：建立了工艺参数与晶粒细化/粗化的映射关系，确定最优加工温度系数为0.23。相较于0.19、0.20、0.21、0.25及0.27等加工温度系数条件下，细化效果分别提升256.0%、146.0%、113.0%、6.7%和52.4%。温度过高会因位错湮灭导致晶粒粗化；施加应变会降低材料实际熔点。即使加工温度未超过理论熔点，仍可能发生熔化与重结晶，引发过烧现象——该现象在减少内部缺陷的同时会导致晶粒整体粗化。本研究对实际锻造工艺设计具有重要指导意义。

Abstract:

Using multi-directional forging temperature as the independent variable and adopting the dual-mode phase field crystal model, the nucleation modes, reaction mechanisms, and interactions between grain boundaries and dislocations at different temperatures were investigated. Results show that a mapping relationship between process parameters and grain refinement/coarsening is established, and the optimal processing temperature coefficient is 0.23. Compared with the cases with processing temperature coefficient of 0.19, 0.20, 0.21, 0.25, and 0.27, the refinement effect increases by 256.0%, 146.0%, 113.0%, 6.7%, and 52.4%, respectively. Excessively high temperatures lead to grain coarsening due to dislocation annihilation, and the application of strain can reduce the actual melting point of materials. Even if the processing temperature does not exceed the theoretical melting point, remelting and crystallization may still occur, resulting in an overburning phenomenon that reduces internal defects and increases overall grain size. This research is of great significance for the actual forging process design.