A Stepped Superplasticity Deformation Method Inducing Plasticity Enhancement of Titanium Alloy

作者：Xu Xuefeng^*; Wang Gaochao; Xia Chunlin

来源：Rare Metal Materials and Engineering, 2012, 41(3): 527-530.

• stepped superplasticity deformation
• plasticity enhancement
• titanium alloy
• elongation
• maximum m SPD

A novel concept of stepped superplasticity deformation (Stepped-SPD) was proposed for exploring a way from superplasticity deformation process to enhance the metal plasticity. In that Stepped-SPD process, the constant speed deformation and the maximum m superplasticity deformation (Max m SPD) were adopted superlatively to finish the tension of samples through two steps. The strain of the first step and clearance time between two steps in Stepped-SPD were controlled in order to facilitate the grain refinement and structure improvement which induced plasticity enhancement. In these experiments, stepped tension deformation was compared with single-step tensile deformation and the influences of pre-strain of the first step in Stepped-SPD on elongation and microstructure were analyzed. The results for TC6 alloy without grain refinement treating show that the Stepped-SPD tensile method obtains the best SPD capability, with an elongation of 2053% corresponding to the pre-strain of 2.0, whereas the Max m SPD and constant speed tensile method produces the biggest elongations of 1347% and 753.9%, respectively. The elongation for TC4 titanium alloy using stepped tensile test is 2147% corresponding to the pre-strain of 1.5 in the first deformation step. Thus, it is indicated that the Stepped-SPD induces the plastic enhancement in comparison with the single-step deformation. Moreover, the pre-strain determines the grain size of the tensile sample in Stepped-SPD.

• 出版日期2012-3
• 单位南昌航空大学