超塑性变形TiAl 基合金中的孔洞

来源期刊：中南大学学报(自然科学版)1998年第6期

论文作者：周科朝 黄伯云 曲选辉

文章页码：49 - 52

关键词：孔洞; 超塑性变形; TiAl基合金

Key words：porosity; superplastic deformation; TiAl based alloy

摘    要：研究了超塑性Ti－33Al－3Cr－0.5Mo(质量分数，%)合金中孔洞的形成和发展过程及其与合金的断裂之间的关系.研究结果表明，TiAl基合金在超塑性变形过程中产生的孔洞有3种类型，它们分别形成于三叉晶界处、晶界上和晶粒内.三叉晶界上的孔洞一般呈V型，而晶界和晶内的孔洞则呈圆形或椭圆形.分析认为，孔洞的长大、扩展和聚集是造成TiAl基合金超塑性拉伸断裂的主要原因.

Abstract: Porosity of Ti－33Al－3Cr－0.5Mo (mass fraction,%) Alloy after superplastic deformation was investigated.The experiments showed that the pore nucleation occured not only at triple points,but Also at grain boundaries,and even within γ grains.Most of the pores at the triple points were present in V shape,and those in grain boundaries and within grains appeared as sphericAl.It was believed that coarsening and coAlescence of the pores were the main reasons of the superplastic fracture of TiAl based Alloy.