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The role of interfacial precipitates on creep behaviour of Power Metallurgy (PM) Ti-48Al-2Cr-2Nb+1W alloy

Journal Article


Abstract


  • Pre-alloyed powders with a nominal composition of Ti-48Al-2Cr-2Nb+1W were consolidated by hot isostatic pressing (HIP). After the HIP process, a step cooled heat treatment (SCHT) with a carefully controlled cooling rate was applied to homogenize the HIP'ed microstructure and produce a fully lamellar microstructure. Following the SCHT, various isothermal aging at 950 ��C and step aging processes form interfacial precipitates at the lamellar interfaces. The morphology, size, and distribution of the precipitates are dependent on the aging condition. Creep tests were carried out in air at 760 ��C and 276 MPa to investigate the effect of interfacial precipitates. Primary creep resistance and creep life of the 8 and 144 hr aged conditions are improved substantially compared to the unaged condition due to the existence of the interfacial precipitates. However, the step aging process improves the creep resistance only slightly, probably because of the size and distribution differences of the interfacial precipitates compared to the 144 hr aged condition. Microstructure control is important since it has a substantial influence on creep behavior, especially primary creep resistance. �� (2010) Trans Tech Publications.

Publication Date


  • 2010

Citation


  • Seo, D., Bulmer, S., Saari, H., Zhu, H., & Au, P. (2010). The role of interfacial precipitates on creep behaviour of Power Metallurgy (PM) Ti-48Al-2Cr-2Nb+1W alloy. Materials Science Forum, 654-656, 496-499. doi:10.4028/www.scientific.net/MSF.654-656.496

Scopus Eid


  • 2-s2.0-77955492961

Start Page


  • 496

End Page


  • 499

Volume


  • 654-656

Issue


Place Of Publication


Abstract


  • Pre-alloyed powders with a nominal composition of Ti-48Al-2Cr-2Nb+1W were consolidated by hot isostatic pressing (HIP). After the HIP process, a step cooled heat treatment (SCHT) with a carefully controlled cooling rate was applied to homogenize the HIP'ed microstructure and produce a fully lamellar microstructure. Following the SCHT, various isothermal aging at 950 ��C and step aging processes form interfacial precipitates at the lamellar interfaces. The morphology, size, and distribution of the precipitates are dependent on the aging condition. Creep tests were carried out in air at 760 ��C and 276 MPa to investigate the effect of interfacial precipitates. Primary creep resistance and creep life of the 8 and 144 hr aged conditions are improved substantially compared to the unaged condition due to the existence of the interfacial precipitates. However, the step aging process improves the creep resistance only slightly, probably because of the size and distribution differences of the interfacial precipitates compared to the 144 hr aged condition. Microstructure control is important since it has a substantial influence on creep behavior, especially primary creep resistance. �� (2010) Trans Tech Publications.

Publication Date


  • 2010

Citation


  • Seo, D., Bulmer, S., Saari, H., Zhu, H., & Au, P. (2010). The role of interfacial precipitates on creep behaviour of Power Metallurgy (PM) Ti-48Al-2Cr-2Nb+1W alloy. Materials Science Forum, 654-656, 496-499. doi:10.4028/www.scientific.net/MSF.654-656.496

Scopus Eid


  • 2-s2.0-77955492961

Start Page


  • 496

End Page


  • 499

Volume


  • 654-656

Issue


Place Of Publication