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XJTU Study Achieves Precise Control of Heterogeneous α Phase Precipitation in Additive Titanium Alloys
2026-05-27
A joint research team from Xi'an Jiaotong University has established a quantitative framework linking cooling rate, solute redistribution, and heterogeneous α precipitation. By integrating phase-field simulations, computational fluid dynamics modeling, and experiments, the study found that at an appropriate cooling rate (about 4.0×10⁵ K/s), significant intragranular solute gradients arise during solidification, triggering spatially heterogeneous α precipitation—coarse α phases form within solute-rich grain interiors via classical nucleation and growth, while fine α phases form near grain boundaries via pseudo-spinodal decomposition. Validated in PBF-LB/M Ti-Mo alloys with optimized parameters, nanoindentation shows that heterogeneous regions achieve higher elastic modulus while maintaining similar hardness. This structural design is expected to simultaneously enhance strength, toughness, and fatigue performance, offering new pathways for microstructural regulation of customized high-performance titanium alloy components.
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西交大研究实现增材钛合金非均匀α相析出精准调控
西安交通大学联合研究团队建立了冷却速率、溶质再分配与非均匀α析出之间的定量关联框架。该研究通过集成相场模拟、计算流体动力学建模与实验，发现适当冷却速率（约4.0×10⁵ K/s）下，凝固过程产生显著晶内溶质梯度，触发空间非均匀α析出——富溶质晶粒内部通过经典形核-长大形成粗大α析出相，晶界附近通过伪旋节线分解形成细小α析出相。经优化参数在PBF-LB/M Ti-Mo合金中验证，纳米压痕显示非均匀区域在保持相近硬度的同时实现更高弹性模量。这种结构设计有望同步提升材料的强度、韧性及疲劳性能，为定制化高性能钛合金部件提供了新的微观结构调控途径。