Effect of Strain Rate on Microstructure Evolution and Mechanical Behavior of Titanium-Based Materials

Metals

SergeyV. Prikhodko¹  VadimI. Bondarchuk²  MykolaA. Skoryk²  PavloE. Markovsky²  OleksandrO. Stasyuk²  DmytroG. Savvakin²  Jacek Janiszewski³  Kamil Cieplak³  Piotr Dziewit³ 

[1] Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA;G.V. Kurdyumov Institute for Metal Physics of N.A.S. of Ukraine, 36, Academician Vernadsky Boulevard, UA-03142 Kyiv, Ukraine;Jarosław Dąbrowski, Military University of Technology, 2, gen. Sylwester Kaliski str., 00-908 Warsaw, Poland;

关键词: titanium alloy;    high strain rate testing;    split hopkinson pressure bar technique;    microstructure influence;    phase transformation;    deformation mechanism;   

DOI  :  10.3390/met10111404

来源: DOAJ

【 摘 要 】

The goal of the present work is a systematic study on an influence of a strain rate on the mechanical response and microstructure evolution of the selected titanium-based materials, i.e., commercial pure titanium, Ti-6Al-4V alloy with lamellar and globular microstructures produced via a conventional cast and wrought technology, as well as Ti-6Al-4V fabricated using blended elemental powder metallurgy (BEPM). The quasi-static and high-strain-rate compression tests using the split Hopkinson pressure bar (SHPB) technique were performed and microstructures of the specimens were characterized before and after compression testing. The strain rate effect was analyzed from the viewpoint of its influence on the stress–strain response, including the strain energy, and a microstructure of the samples after compressive loading. It was found out that the Ti-6Al-4V with a globular microstructure is characterized by high strength and high plasticity (ensuring the highest strain energy) in comparison to alloy with a lamellar microstructure, whereas Ti6-Al-4V obtained with BEPM reveals the highest plastic flow stress with good plasticity at the same time. The microstructure observations reveal that a principal difference in high-strain-rate behavior of the tested materials could be explained by the nature of the boundaries between the structural components through which plastic deformation is transmitted: α/α boundaries prevail in the globular microstructure, while α/β boundaries prevail in the lamellar microstructure. The Ti-6Al-4V alloy obtained with BEPM due to a finer microstructure has a significantly better balance of strength and plasticity as compared with conventional Ti-6Al-4V alloy with a similar type of the lamellar microstructure.

【 授权许可】

Unknown