A Study on the Dynamic Behavior of Ti-6Al-4V Alloy

Seo, Yongseok; Lee, Young-Shin; Song, Ohseop

doi:2017.20.2.206

J. KIMS Technol > Volume 20(2); 2017 > Article

Journal of the Korea Institute of Military Science and Technology 2017;20(2):206-216.
DOI: https://doi.org/10.9766/KIMST.2017.20.2.206

A Study on the Dynamic Behavior of Ti-6Al-4V Alloy

Yongseok Seo, Young-Shin Lee, Ohseop Song

¹The 5th Research and Development Institute, Agency for Defense Development
²Department of Mechanical Engineering, Chungnam National University

Ti-6Al-4V 합금의 동적 변형 거동에 관한 연구

서용석, 이영신, 송오섭

¹국방과학연구소 제5기술연구본부
²충남대학교 기계공학부

Abstract

This paper studies on the dynamic properties of Ti-6Al-4V alloy. After forming the four different micro structures(equiaxed, lamellar, and 2 bimodals) through heat treatments, static and dynamic properties of each structure were investigated quantitatively. Dynamic behaviors of the alloy are observed by the compressive split Hopkinson pressure bar(SHPB) tests. In additon, parameters of Johnson-Cook equation were determined from the SHPB test results. In order to verify the suitability of the parameters, high velocity impact tests were performed and the results were compared with the numerical analysis results. Although the flow stress and the fracture strain of the bimodal structures were higher than those of the equiaxed structure at the static tests, the superior dynamic properties were observed at the equiaxed structure due to the effects of higher maximum flow stress and fracture strain. From the numerical analysis, J-C parameters which are determined on this study describe well the dynamic behavior of Ti-6Al-4V alloy. Experimental and analysis results are consistent with ${pm}5%$ of an average error.

Key Words: Ti-6Al-4V, Dynamic Behavior, Compressive Split Hopkinson Pressure Bar Test, High Velocity Impact Test, Johnson-Cook Equation