摘要
等轴γ晶粒和α2/γ片层是beta-gamma TiAl合金的2种主要变形组织形态。研究了锻态Ti-44Al-4Nb-4V-0.3Mo-Y合金等轴组织及片层组织的高温拉伸性能及组织演变。结果表明:拉伸温度对Ti-44Al-4Nb-4V-0.3Mo-Y合金的力学性能和显微组织有显著的影响。在相同温度下,Ti-44Al-4Nb-4V-0.3Mo-Y合金等轴组织的抗拉强度和屈服强度略高于片层组织,而延伸率相差不大。随拉伸温度的升高,合金的抗拉强度和屈服强度逐渐减小,而延伸率迅速增大。对于等轴组织,提高温度,等轴γ晶粒被拉长,发生完全的动态再结晶,从而细化合金的显微组织。对于片层组织,α2/γ片层的分解和γ板条的再结晶程度随拉伸温度的升高而增大。Ti-44Al-4Nb-4V-0.3Mo-Y合金的韧脆转变温度在750~800℃之间。
The equiaxedγgrains andα2/γlaminae are the two main deformed microstructure of beta-gamma TiAl alloy.In this paper,mechanical properties and microstructural evolution of hot forged Ti-44 Al-4 Nb-4 V-0.3 Mo-Y alloy with equiaxed and lamellar microstructures were studied under high temperature tension.The results show that tensile temperature has a significant effect on the mechanical properties and microstructures of Ti-44 Al-4 Nb-4 V-0.3 Mo-Y alloy.At the same temperature,the tensile strength and yield strength of the TiAl alloy with equiaxed microstructure are slightly greater than those of lamellar structure;however the elongation difference is not significant.With the increase of tensile temperature,the tensile strength and yield strength of TiAl alloy decrease gradually,while the elongation increases significantly.For equiaxed microstructure,when increasing tensile temperature,the equiaxedγgrains are elongated and complete dynamic recrystallization occurs to refine the microstructure of the TiAl alloy.For lamellar microstructure,the degree of decomposition ofα2/γlaminae and recrystallization ofγlaths increase with the increase of tensile temperature.The ductile brittle transition temperature of Ti-44 Al-4 Nb-4 V-0.3 Mo-Y alloy is between 750~800℃.
作者
曹小平
张树玲
张长江
张树志
Cao Xiaoping;Zhang Shuling;Zhang Changjiang;Zhang Shuzhi(Taiyuan University of Technology,Taiyuan 030024,China;Ningxia University,Yinchuan 750021,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2020年第7期2346-2351,共6页
Rare Metal Materials and Engineering
基金
国家自然科学基金项目(51604191,51504153,51604159)
山西省自然科学基金(201701D221075)
太原理工大学青年专项基金(2015QN014)。
关键词
TIAL合金
微观组织演变
高温拉伸
机械性能
TiAl alloy
microstructural evolution
high temperature tension
mechanical properties