摘要
研究了SPZ钛合金的超塑性变形及其变形前后的显微组织。研究结果表明,大塑性变形后,SPZ合金轧棒组织为利于超塑性的细小均匀的等轴组织。SPZ合金在740℃～800℃之间具有超塑性,在760℃,初始应变速率为1.11×10^(-3)s^(-1)时,合金的最大超塑延伸率可达2149％；应变速率为1.11×10.^(-2)s^(-1)时,超塑延伸率仍可达1380％。超塑性变形后的晶粒尺寸比变形前粗大,变形温度越高,晶粒长大程度越大。变形前合金的晶粒尺寸为0.89μm；应变速率为2.22×10^(-3)s^(-1)时,在740℃,760℃,780℃变形后晶粒尺寸分别为1.51μm,2.33μm,3.21μm。SPZ合金超塑性变形的微观机制足以晶界滑动为主,晶内变形以及位错蠕变起协调作用。合金超塑性变形与类流态的关系还有待深入研究。
Microstructures and superplastic properties of SPZ titanium alloy were studied. The results indicate that homogeneous, fine-grained spherical structures are found in the as-rolled bars, which is beneficial to superplastic deformation. The alloy possesses surperplastic properties at the temperature region from 740℃ to 800℃, the maximum elongation is 2149% and 1380%, respectively for the alloy deformed at 760℃ with the primary strain rate of 1.11× 10%-3s^-1 and 1.11 × 10^-2s^-1. The grain sizes before superplastic deformation are about 0.89μm, and which are 1.51μm, 2.33μm, 3.21μm, respectively for the alloy deformed at 740℃, 760℃ and 780℃ with the primary strain rate of 2.22×10^-3s^-1, which means, the grain sizes will become larger after superplastic deformation, and will also increase with the increment of superplastic deformation temperature. The deformation behavior of the alloy has typical fine-grained superplasticity feature. The superplastic deformation mechanism is mainly for boundary sliding, deformation inside the grains and dislocation creep has assistant effect. The relationship between superplastic deformation and quasi-fluid state should be studied further.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2005年第12期1940-1943,共4页
Rare Metal Materials and Engineering
关键词
超塑性
微观组织
变形机制
α+β型钛合金
superplasticity
microstructure
deformation mechanism
α plus β type Ti alloy
