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conferenceseries
.com
Volume 5, Issue 6 (Suppl)
J Mat. Sci.
ISSN: 2321-6212
Advanced Materials 2017
October 26-28, 2017
OCTOBER 26-28, 2017 OSAKA, JAPAN
13
TH
INTERNATIONAL CONFERENCE ON
Advanced Materials and Nanotechnology
Melting, forging and phase transformation of a Mn containing β stablized γ-TiAl
Kui Liu, Hao Xu, Xiaobing Li, Lei Shu and Yingche Ma
Chinese Academy of Sciences, China
T
iAlMn alloys are lightweight, low cost material with good mechanical property and proper oxidation resistance, always
seemed as a promising material for automotive industrial application. This research was mainly focused on the VIM and
conventional forging of a β-stabilized Ti-42Al-5Mn alloy, exploring the possibility that whether such cost-effective process
can be applied to manufacturing advanced γ-TiAl. The oxygen-enrichment study and melting ingot analysis show that the
contamination induced by strong interaction between molten liquid and crucible can be minimized when the thermodynamic
stable CaO crucible and proper melting technique were adopted. The low oxygen content (<800 ppm) and chemically
homogenized (main-element within ±0.2%) alloy can be successfully produced with IMR improved melting technique. With
regards to conventional forging, based on hot deform mechanism and the phase transformation behavior studies, both the
single step 10 kg VIM and 25 kg VIM+VAR ingots were successfully forged at a right hot deforming temperature with proper
press descent speed. Finally, the microstructural evolution has been investigated for the forging bar by subjecting to solution
and annealing two-step heat treatment. It was found that γ-phases cannot dissolve into β-phases when the solution temperature
was below T
solv
(1220
o
C). The undissolved γ-phases will be coarsening in the following 800
o
C annealing. Contrarily, when the
solution temperature was above T
solv
the γ-phases were dissolved completely and plenty of refined γ-platelets will precipitate
from β-phases during air cooling. Thereafter, the γ-platelets will be stable with the above regime. In general, this work can
provide a strong technical support for developing the cost-effective γ-TiAl alloys.
Biography
Kui Liu has received his PhD from the Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) in 1999. He is a Group Leader of the Materials for
Special Engineering in the Division of Materials for Special Environment of IMR. He has published more than 40 papers and holds more than 25 patents. The main
research interests of him are special melting high purity reactive materials, like Ni base, NiTi shape memory and TiAl alloys.
kliu@imr.ac.cnKui Liu et al., J Mat. Sci. 2017, 5:6
DOI: 10.4172/2321-6212-C1-008