γ－TiAl单晶位错滑移特性的研究

INVESTIGATION OF DISLOCATIONS SLIP CHARACTERISTIC IN A γ TiAl SINGLE CRYSTAL

利用透射电子显微术对Ｔｉ－５６％Ａｌ（原子分数）单晶变形亚结构中位错的滑移特性进行了研究．结果表明：γ－ＴｉＡｌ相单晶在室温下，沿［１１２］方向受力产生的可动位错系为｛１１１｝１／２〈１１２］型超位错，位错滑移方向为〈１１０］或〈１３２］；位错线轴向处于〈１１０］或〈１３２］方向的部分由于受到Ｐｅｉｅｒｌｓ应力势的限制而变为难滑移部分。

Slip characteristic of dislocations in a γ TiAl single crystal with the orientation deformed at room temperature was observed by transmission electron microscopy. The results indicated that only super dislocations with 1/2〈112] type Burgers vector can operate. Slip directions of dislocations were 〈110] or 〈132] directions. Parts of dislocation with their axes at right angles to directions 〈110] or 〈132] could be sessile as a result of entrance in. The result of the dislocation continuously moving caused a couple of dislocations lines with straight morphology along the 〈110] or 〈312] direction.