摘要
研究了一种(α2+O+B2)三相Ti3Al基合金环锻件的微观组织和力学性能,结果表明:在(α2+B2)两相区充分变形的、具有均匀分布的等轴初生α2相和片状O相的锻件能够获得良好的高温强度性能和室温塑性;β单相区变形的、具有粗大片状组织形貌的锻件拉伸强度和延伸率都很低;(α2+B2)两相区少量变形的、具有短棒状初生α2相的锻件除了拉伸塑性差以外,高温持久性能也很差;锻件微观组织中异常的长片O相存在会降低合金的塑性性能。控制锻件在(α2+B2)两相区变形前的β晶粒的尺寸以及保证在(α2+B2)两相区足够的变形量非常关键,以避免晶界α2相和长片初生O相,提高微观组织的均匀性和锻件的拉伸塑性性能。提高(α2+O+B2)三相Ti3Al基合金的Mo含量有助于蠕变性能。
The microstructure and mechanical properties of a kind of （α2＋O＋B2） three-phase Ti3Al based alloy ring forgings were studied. The results showed that the forgings with uniform equiaxed primary α2 phase and O laths obtained through fully deformation in （α2＋B2） phase field had good high temperature strength and room temperature ductility. However the forging with coarse lamella microstructure obtained through β phase field processing displayed poor tensile strength and ductility. The forging with short-bar-like primary α2 phases because of less deformation in （α2＋B2） phase field provided poor tensile ductility and creep rupture properties. Abnormal long O phase laths worsen the tensile ductility of the forgings. The refinement of β grain sizes before （α2＋B2） phase field processing and enough deformation in （α2＋B2） phase field are critical to avoid abnormal long O laths and grain boundarya2 phase so as to improve the microstructure uniformity and tensile ductility of forgings. It is also proved that the increase of Mo content is good to improve the creep properties of （α2＋O＋B2） three-phase Ti3Al based alloy.
出处
《钛工业进展》
CAS
2008年第5期15-19,共5页
Titanium Industry Progress
