Preparation and Properties of Ti-47Al-2Cr-2Nb-0.15B Alloy by Powder Metallurgy Route

Abstract:

Ti-47Al-2Cr-2Nb-0.15B alloy is a typical γ-TiAl alloy, and powder metallurgy (PM) as a near-net shape method was used to prepare it in this article. Clean pre-alloyed powders were prepared by argon gas atomization, and TiAl alloy was prepared by hot isostatic pressing (HIP) at 1150 °C and 1230 °C. However, surface contamination is inevitable due to chemical reactions with the residual O₂ in the vacuum chamber during gas atomization, or due to physical adsorption of O₂ and H₂O during storage of the powder at room temperature. Infrared spectrometry was used to study this process. We found that the adsorption of gases is mainly H₂O. The adsorbed gas in powders would deteriorate the performance of PM alloy, so a gas protection environment is suggested. Tensile properties of PM TiAl alloy were compared with as-cast alloy. Results showed that PM TiAl alloy had better strength which also had more fine and uniform microstructure.

• Periodical: Materials Science Forum (Volume 817)
• Pages: 615-620
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.817.615
• Online since: April 2015
• Authors: Zheng Guan Lu, Jie Wu, Lei Xu, Yu You Cui, Rui Yang
• Keywords: Hot Isostatic Pressing (HIP), Powder metallurgy, TiAl, Vacuum Degassing

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