• CN:11-2187/TH
  • ISSN:0577-6686

›› 2011, Vol. 47 ›› Issue (6): 39-44.

• 论文 • 上一篇    下一篇

TiAl金属间化合物基合金压缩断裂行为

曹睿;李雷;张继;何洪;陈剑虹   

  1. 兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室;西安赛特金属材料开发有限公司;钢铁研究总院高温材料研究所;中国北方发动机研究所
  • 发布日期:2011-03-20

Compression Fracture Behaviors of TiAl Intermetallics Based Alloys

CAO Rui;LI Lei;ZHANG Ji;HE Hong;CHEN Jianhong   

  1. State Key Laboratory of Gansu Advanced Non-Ferrous Metal Materials,Lanzhou University of Technology Xi’an Dorset Metal Materials Development Co. High Temperature Materials Division, China Iron and Steel Research Institute Group China North Engine Research Institute
  • Published:2011-03-20

摘要: 通过对压缩试样的加载—卸载以及加载—卸载—再加载等试验和相应的裂纹观察、断口观察,详细研究TiAl金属间化合物基合金压缩断裂行为。研究结果表明:压缩预加载产生的损伤对压缩断裂行为没有影响,然而对后续的拉伸断裂行为则产生影响,一定程度上大大降低其拉伸断裂应力。对全层和双态组织来说,剪切开裂首先产生于顶面或底面,在压缩试验中顶面和底面的切应力是主要的控制因素。最终的断裂是由顶面和底面产生的剪切裂纹扩展到试样中部并相互连接而诱发。对于双态组织(Duplex, DP)和全层组织(Fully lamellar, FL)来说,纵向开裂的形成原因不同。压缩和拉伸性能的巨大差异是由于其断裂机理不同引起,拉伸试验断裂主要是由正应力控制,然而压缩试验中断裂主要是由切应力控制。

关键词: TiAl金属间化合物基合金, 断裂机理, 压缩试样

Abstract: Based on the results of preloading-unloading and preloading-unloading-reloading compression testing, observations of corresponding cracks and fracture surfaces for TiAl intermetallics based-alloys, compression fracture behaviors are studied in detail. The results show that the compression preloading has no influence on the compression fracture behavior, but has effect on the subsequent tensile fracture behavior, i.e. drastically reducing the tensile fracture stress. For both fully lamellar(FL) and duplex(DP) specimens the shear cracking first starts from the top or /and the bottom surface. In the compression testing, the shear stresses at the top or/and the bottom surfaces are the controlling parameters. The final fracture is induced by the shear cracks produced at the top and bottom surfaces and expanding to the center of specimen and mutually connected. The causes of the longitudinal cracking are different for DP and FL alloys. The much lower values of the b measured in tensile tests are attributed to the difference of the fracture mechanisms between the tensile test and the compression tests of the TiAl alloy. For the tensile test the fracture mechanism is the cleavage fracture caused by the tensile normal stress, while for the compression test it is controlled by the shear cracking.

Key words: Compression tests pecimen, Fracture mechanism, TiAl intermetallics based alloys

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