热处理对一种两相钛合金超塑性及组织的影响

Microstructures and superplastic properties of one kind of two phase titanium alloy varied with heat treatment condition

对经不同制度处理的一种富β的α+β型钛合金(SPZ)的超塑性性能及组织进行了研究.结果表明,700℃/1 h AC处理后,合金具有良好的室高温性能;应变速率高达1.11×10-3/s时,合金在740℃～800℃温度范围内显示出超塑性,超塑拉伸延伸率均超过1600%;760℃,合金拉伸延伸率可高达2149%.扫描电镜(SEM)观察发现,SPZ合金的变形行为具有明显细晶超塑性的特点.应变速率为2.22×10-3/s时,740℃、780℃变形后晶粒尺寸分别为1.51 mm、3.21 mm.超塑变形后合金的晶粒尺寸比变形前的有所增大;超塑性温度越高,晶粒长大程度越高.

Microstructures and superplastic properties with variation of heat treatment condition of one kind of a plus β type titanium alloy were studied in this paper. The results indicated that the alloy annealed at 700℃ for lh posseses favorite integrated properties at ambient and elevated temperature. The alloy possess superior superplastic property deformed between 740℃ and 800℃ with the orunart strain rate of 1.11 × 10^-3 s^-1, the elongation of the alloy is over 1600 % ;the maximum elongation for the alloy deformed at 760℃ is up to 2149 %. The deformation behavior for the alloy has the typical fine-grained superlasticity feature. The grain size is 1.51μm and 3.21μm respectively for the alloy deformed at 740℃ and 780℃ with the strain rate of 2. 22 - 10^-3s^-1. The grain size would increases after superplastic deformation, and should increase with the increment of superplastic temperature.