TY - JOUR
T1 - Microstructure and properties of beta Ti-Nb alloy prepared by powder metallurgy route using titanium hydride powder
AU - Sharma, Bhupendra
AU - Vajpai, Sanjay Kumar
AU - Ameyama, Kei
N1 - Funding Information:
This research was supported by the Grant-in-Aid for Scientific Research on Innovative area, Bulk Nanostructured Metals through MEXT, Japan (contract No. 22102004). These supports are gratefully appreciated.
Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/10/14
Y1 - 2015/10/14
N2 - In the present work, Ti-40 mass%Nb alloys were successfully fabricated by a powder metallurgy route consisting of mechanical alloying (MA) of TiH2-Nb powder mixture and spark plasma sintering (SPS). The use of brittle TiH2 powder, instead of ductile elemental powder, led to significant increment in the yield of mechanically alloyed (MAed) powder. The MAed powder consisted of homogeneously distributed nano-sized Ti/Nb hydride particles together with micron-sized pure Nb particles. The MA also led to the lowering of dehydrogenation temperature of hydride particles. Sintering of MAed powders under low temperature conditions (1223 K, & 1373 K) resulted in the fine-grained heterogeneous microstructure consisting of α, β, and unreacted pure Nb phase. On the other hand, sintering at higher temperatures (1523 K) resulted in a relatively coarse-grained chemically homogeneous microstructure with almost complete β phase. Coarse-grained homogeneous β Ti-Nb alloy exhibited higher average hardness as compared to that of heterogeneous fine grained microstructures. An attempt has been made to illustrate the correlation between the microstructural characteristics and mechanical properties of the sintered Ti-40Nb compacts.
AB - In the present work, Ti-40 mass%Nb alloys were successfully fabricated by a powder metallurgy route consisting of mechanical alloying (MA) of TiH2-Nb powder mixture and spark plasma sintering (SPS). The use of brittle TiH2 powder, instead of ductile elemental powder, led to significant increment in the yield of mechanically alloyed (MAed) powder. The MAed powder consisted of homogeneously distributed nano-sized Ti/Nb hydride particles together with micron-sized pure Nb particles. The MA also led to the lowering of dehydrogenation temperature of hydride particles. Sintering of MAed powders under low temperature conditions (1223 K, & 1373 K) resulted in the fine-grained heterogeneous microstructure consisting of α, β, and unreacted pure Nb phase. On the other hand, sintering at higher temperatures (1523 K) resulted in a relatively coarse-grained chemically homogeneous microstructure with almost complete β phase. Coarse-grained homogeneous β Ti-Nb alloy exhibited higher average hardness as compared to that of heterogeneous fine grained microstructures. An attempt has been made to illustrate the correlation between the microstructural characteristics and mechanical properties of the sintered Ti-40Nb compacts.
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U2 - 10.1016/j.jallcom.2015.10.053
DO - 10.1016/j.jallcom.2015.10.053
M3 - Article
AN - SCOPUS:84944754520
VL - 656
SP - 978
EP - 986
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -