室温等径弯曲通道变形工业纯钛的组织及性能研究

Study on Microstructure and Properties of Commercial Pure Titanium by Equal Channel Angular Pressing at Room Temperature

采用两通道夹角Φ=120°,外圆角Ψ=20°的模具,在室温下成功实现了工业纯钛单道次等径弯曲通道变形(ECAP),并对变形试样进行(200～500)℃×0.5h退火,研究了试样显微组织和力学性能。结果表明,工业纯钛经单道次ECAP变形后,组织内存在大量的形变孪晶;晶粒碎化成板带状组织;屈服强度和显微硬度显著提高,并保持了足够的塑性;退火温度低于300℃时,显微硬度下降缓慢;高于300℃时,显微硬度显著下降。

A single equal channel angular pressing （ECAP） at room temperature was successfully carried out in commercial pure （CP） Ti at an internal angle Φ=120° and an outer curvature angle Ψ=20° ,then the as-pressed CP Ti was annealed at 200～500℃ for 0.5 h. The microstructure and mechanical properties ofCP Ti were studied. The results show that, after a single ECAP, deformation twins are produced, and grains break into segments and forme shear bands; yield strength and microhardness significantly enhance, while maintaining good ductility; microhardness slightly decreases below 300℃ annealing, then microhardness decreases sharply above 300℃ annealing.