摘要
通过扫描电镜的背散射电子(BSE)、透射电子显微镜(TEM)以及拉伸和高周疲劳实验研究了对Ti-44Al-4Nb-4Zr-0.2Si-1B进行等温热锻后组织以及力学性能的变化。结果表明等温热锻后板条厚度、B2+ω相、等轴γ相的体积含量均有很大程度的下降,而晶粒尺寸和α2+γ板条体积分数则有增大的趋势。部分板条发生一定的弯曲畸变。抗拉强度和屈服强度提高约80 MPa,断裂延伸率仍处于较低的水平,无明显提高。疲劳极限提高约230 MPa。并分析了硼化物、板条厚度、B2+ω相等对力学性能的影响机制。
The effect of isothermal forging on micro- structure and mechanical properties of Ti-44Al-4Nb- 4Zr-0.2Si-1B alloys was investigated by means of BSE , TEM, tensile and the high cycle fatigue test at room temperature. The results showed that the lamellar thickness and volume fraction of equiaxed γ phases and B2 ＋ ω phases decreased, the grain size and vol- ume fraction of lamellar α2 ＋ γcolonies was raised after isothermal forging. Part the lamellar batten was of bending aberrance to some extent. The tensile strength and yield strength were increased by 80 MPa, but the total elongation almost kept unchanged. The fatigue limit was increased by 230 MPa. The effects of bo- ride, lamellar thickness and B2 ＋ ω phases on the me- chanical properties were studied.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2009年第4期472-477,共6页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(50471046)
西南交通大学青年教师科研起步项目资助(2007Q012)
关键词
Γ-TIAL
等温热锻
板条厚度
力学性能
γ-TiAl
isothermal forging
lamellar thickness
mechanical properties
