Effect of yttria inclusion on room temperature tensile properties of investment cast TiAl

Research output: Contribution to journalArticle

Authors

  • Bochao Lin
  • Renci Liu
  • Qing Jia
  • Yuyou Cui
  • Rui Yang

Colleges, School and Institutes

External organisations

  • Institute of Metal Research, Chinese Academy of Sciences
  • University of Chinese Academy of Sciences

Abstract

Yttria is the best face coat material in the shell mold for the investment casting of γ-TiAl alloys. However, yttria inclusions may occur in the cast products and there is a lack of knowledge about the influence of yttria inclusions on the mechanical properties of TiAl. In the present study, the effect of yttria inclusions on room temperature tensile properties of two investment cast TiAl alloys, Ti-45Al-2Mn-2Nb (at%) + 0.08 vol% TiB2 and Ti-46 Al-2 Nb-2Cr-0.15B (at%), were studied. The results show that tensile failure tends to initiate from yttria inclusions, resulting in reduced plastic strain and ultimate strength. Yttria inclusions differ in location (surface /internal), size, and morphology (agglomerate /whole piece), those with larger sizes or located at the sample surface being more harmful. The tensile properties of inclusion containing TiAl parts can be estimated using the size and location determined by X-ray inspection. The critical size at which inclusions become detrimental to the mechanical properties of TiAl was discussed.

Details

Original languageEnglish
Pages (from-to)73-79
JournalMaterials Science and Engineering A
Volume712
Early online date26 Nov 2017
Publication statusPublished - 17 Jan 2018

Keywords

  • TiAI , investment casting , yttria inclusion , tensile properties