The microstructure and tensile properties of the processed TC17 via high energy shot peening (HESP) were investigated, in which special attention was paid to reveal the fracture behaviour of the HESP processed surface layer. The results indicated that the severe plastic deformation (SPD) zone with the nanograins appeared in the HESP processed surface layer of TC17, in which the SPD thickness increased with the increasing of air pressure while it increased firstly and then decreased with the prolonging of peening duration, and the finer nanograins could be obtained at the higher air pressure and longer peening duration. Due to the generation of gradient structure layer, the HESP processed TC17 had ruptured in a hybrid fracture. The fracture features corresponding to nanograined structure, ultrafine-grained structure and the coarse-grained structure were the brittle fracture, the mixed fracture and the ductile fracture respectively. Comparing with the properties of the annealed TC17, the HESP processed TC17 possessed a better strength-ductility balance owing to combined effects of grain refinement, high-density dislocations, work hardening and compressive residual stress (CRS), in which the yield strength (YS) and the ultimate tensile strength (UTS) were increased by 10.1% and 13.9%, respectively.

研究了通过高能喷丸（HESP）处理的TC17的微观结构和拉伸性能，其中特别注意揭示了HESP处理的表面层的断裂行为。结果表明，在TC17的HESP处理后的表层中出现了具有纳米晶粒的严重塑性变形（SPD）区，其中SPD的厚度随气压的增加而增加，而随着喷丸时间的延长其厚度先增加后减小。 ，并且在更高的气压和更长的喷丸持续时间下可以获得更细的纳米颗粒。由于生成了梯度结构层，经过HESP处理的TC17在混合裂缝中破裂。断裂特征对应于纳米颗粒结构，超细组织和粗组织分别为脆性断裂，混合断裂和韧性断裂。与退火的TC17的性能相比，由于晶粒细化，高密度位错，加工硬化和压缩残余应力（CRS）的综合作用，HESP加工的TC17具有更好的强度-延展性平衡，其中屈服强度（YS ）和极限拉伸强度（UTS）分别增加了10.1％和13.9％。