(1. 北京科技大學(xué) 材料物理系， 北京 100083;
2. 北京航空航天大學(xué) 材料科學(xué)與工程系， 北京 100083)
摘 要: 通過(guò)單軸壓縮及TEM原位拉伸研究了全層狀TiAl合金(PST晶體)中α2板條的形變和斷裂特征。結(jié)果表明，全層狀TiAl合金中α2相形變和斷裂特征與加載方向有關(guān)。當(dāng)片層與加載軸平行時(shí)，α2相中的滑移沿柱面進(jìn)行，微裂紋優(yōu)先在α2相內(nèi)(沿柱面)形核；而當(dāng)片層與加載軸垂直時(shí)，形變困難，α2相中的滑移將沿角錐面進(jìn)行，微裂紋很容易沿相界面形核、擴(kuò)展。
關(guān)鍵字: 全層狀TiAl合金；α2板條； 形變； 斷裂
fully lamellar TiAl alloys
WANG Yan-bing1, CHEN Chang-qi2, CHU Wu-yang1
（1. Department of Materials Physics， University of Science and Technology Beijing，Beijing 100083, P.R.China;
2. Department of Materials Science and Engineering，
Beijing University of Aeronautics and Astronautics， Beijing 100083, P.R.China）
Abstract:The deformation and fracture characteristics of α2 plates in fully lamellar TiAl alloys (PST crystals) were investigated through uniaxial compression and insitu TEM technique. The results indicate that the deformation and fracture characteristics of α2 plates in fully lamellar TiAl alloys are related to the loading direction. When the lamellae are parallel to the loading axis， the slips in α2 plates occur along prism planes and microcracks form preferentially within α2 plates (along prism planes); when the lamellae areperpendicular to the loading axis， the deformation is relatively difficult， and the slips in α2 plates occur along pyramidal planes and microcracks form easily and propagate along γ/α2 interfaces.
Key words: fully lamellar TiAl alloy; α2 plates; deformation; fracture
