In this paper, the effect of equal channel angular pressing (ECAP) on microstructure, mechanical, and erosion-corrosion behavior of commercial pure (CP) titanium was investigated through experimental work. Four passes of ECAP processing at 400 ℃ was performed on CP titanium. The results showed that the homogeneous structure and coarse equiaxed grains of the initial annealed sample are transformed into the combination of UFG and NS with an average size of 750 nm and 85 nm, respectively. Also, ECAP pass numbers increase the fraction of high angle grain boundaries which improves the ductility of the processed sample. The highest hardness and strength improvement rate was observed after the first pass. Furthermore, the increasing rate of hardness and strength is gradually decreased at the subsequent passes and reached the steady-state level at the 4th pass. This is due to the balance between hardening by dislocations and twinnings accumulation and softening by recovery mechanisms. As a result, a uniform hardness distribution on both the cross-sectional and longitudinal planes is achieved. It was confirmed that erosion-corrosion resistance of the processed sample is enhanced due to the grain refinement, material homogeneity, and quick formation of a strong oxide bond layer on the surface.

本文通过实验研究了等通道角挤压（ECAP）对商用纯（CP）钛的微观结构，力学性能和腐蚀腐蚀行为的影响。在CP钛上进行了400℃的四次ECAP处理。结果表明，初始退火样品的均质结构和等轴晶粒粗大，分别转变为UFG和NS的组合，平均尺寸分​​别为750 nm和85 nm。同样，ECAP的通过次数增加了高角度晶界的比例，从而提高了加工样品的延展性。第一次通过后，观察到最高的硬度和强度改善率。此外，硬度和强度的增加速率在随后的遍中逐渐降低，并在第四遍达到稳态水平。这是由于位错硬化和孪晶积累与恢复机制软化之间的平衡。结果，在横截面和纵向平面上均获得均匀的硬度分布。已经证实，由于晶粒细化，材料均质性以及在表面上快速形成强氧化物键合层而提高了加工样品的耐腐蚀腐蚀性。