TC18钛合金的组织和性能与热处理制度的关系

通过三因素三水平正交设计方法研究了两阶段退火热处理制度的三个温度阶段对TC18钛合金性能、组织的影响,定量分析了合金热处理温度变化对总体性能的影响,结果表明,在本文试验条件下可通过提高中温温度、降低低温温度来提高合金的强度,降低高温温度、提高低温温度可改善合金的塑性,通过降低高温温度或中温温度可提高合金的冲击韧性,显微组织分析表明,TC18钛合金的强度主要受未转变β组织及在其上产生的次生αs相的总的含量、次生αs相的含量、形状的控制;合金的塑性受初生αp相形状及次生αs相的数量、形状控制;合金的冲击韧性受初生αp相的含量及形状控制.

The relationship of heat treatment-microstructures-mechanical properties of the TC18 titanium alloy

Through the 3×3 orthogonal experimental design methods, the influences of the different temperature stages of 2–step annealing heat treatment on the mechanical properties and the microstructures of the TC18 titanium alloy were investigated. The influence of the changes of temperature on the mechanical properties was quantitatively analyzed. The results show that the stress level can be increased by increasing the middle–stage of temperature and lowering the low–stage of temperature; the elongation level can be increased by lowering the high–stage temperature and increasing the low–stage temperature; and the impact toughness can be upgraded also by lowering the high–stage and the middle–stage temperature. The stress levels of TC18 titanium can be controlled by the amounts of the β phase and α_s phase, the shape of α_s phase; the elongation levels can be controlled by the shape of αp phase and the shape of the αs phase; and the impact toughness is controlled by the shape and the amounts of the α_p phase.