MICROSTRUCTURE EVOLUTION AND PROPERTIES OF TI-6AL-4V ALLOY DOPED WITH Fe AND Mo DURING DEFORMATION AT 800C

Author(s):  D.N. Klimenko, Belgorod State University, Belgorod , Russia, klimenko@mail.ru

M.S. Ozerov, Belgorod State University, Belgorod , Russia, ozerov@bsu.edu.ru

N.D. Stepanov, Belgorod State University, Belgorod , Russia, stepanov@bsu.edu.ru

N.Yu. Zherebtsova, candidate of Sciences, associate Professor, Belgorod State University, Belgorod , Russia, zherebtsov@bsu.edu.ru

S.V. Zherebtsov, Dr., Prof., Belgorod State University, Belgorod , Russia, zherebtsov@bsu.edu.ru

Issue:  Volume 51, № 2

Rubric:  Physics

Annotation:  The alpha/beta titanium alloys Ti-6Al-4V and Ti-6Al-4V-0.75Mo-0.5Fe were heat treated to produce a stable colony microstructure and were compressed in air at a nominal strain rate of 10-3 s-1 to a height reduction of 25, 50, or 70 % at 800C. Microstructure evolution and mechanical behavior of alpha/beta Ti-6Al-4V and Ti-6Al-4V-0.75Mo-0.5Fe titanium alloys during uniaxial compression was studied. The plastic-flow response for both alloys is characterized by successive stages of strain hardening, flow softening, and steady-state flow. A higher content of beta stabilizers in Ti-6Al-4V-0.75Mo-0.5Fe alloy results in a higher percentage of the beta phase, thicker alpha lamellae and greater mismatch between the alpha and beta lattices. During compression the lamellae spheroidized to produce a partially or entirely globular microstructure. Specifically globularization of the Ti-6Al-4V-0.75Mo-0.5Fe microstructure was faster, that can be associated with easer loss of the initial Burgers-type coherency between the alpha and beta phases and the subsequent individual deformation of each phase. As a result after 70% deformation, the globalarized fraction was ~ 100% for Ti-6Al-4V-0.75Mo-0.5Fe and ~ 30% for Ti-6Al-4V. This difference can be partially associated with different interphase energy due to doping of the -stabilizing elements.

Keywords:  Titanium alloy, compression, microstructure evolution, globularization

Full text (PDF):  Download

Downloads count:  273