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| Microstructure and mechanical properties of fine-grained TC4 alloy prepared by
powder metallurgy |
| ZHANG Hui，ZHAO Yabin，PAN Aiqiong |
| School of Mechanical Engineering，Zhengzhou University of Science & Technology，Zhengzhou 450064，
China, |
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Abstract In the present work, fine-grained TC4 titanium alloy was prepared by the means of vacuum hot pressing
sintering + hot extrusion + annealing treatment. The evolution of microstructure and mechanical properties of titanium
alloy during the preparation were studied. The results show that the hot-pressed sintered TC4 titanium alloy
is mainly composed of α and β phase, α phase is distributed in an equiaxial manner and β phase is distributed in the
inner grain or grain boundary of α phase with an elongated lamellar/acicular. After hot extrusion, the grain sizes of
TC4 titanium alloy obtained by vacuum hot-pressing sintering can be significantly reduced to form fine-grained microstructure,
which is benefit for the improvement of tensile strength from 837 MPa to 983 MPa. However, the fracture
elongation is the lowest at 9.6%. Further annealing can restore and recrystallize the hot extruded TC4 titanium
alloy, especially the β phase grains formed equiaxed grains and distributed around the α grains in a spot-like manner,
which is beneficial to improve the plasticity and toughness of TC4 titanium alloy. Therefore, the fine-grained
TC4 titanium alloy obtained by hot pressing sintering + hot extrusion + annealing treatment has relatively excellent
comprehensive properties.
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Received: 06 March 2021
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2021, Vol. 31 
