Multipass-friction Stir Processing (MFSP) of Ti-6Al-4V Alloy and Investigation of Flow Properties

2018 International Conference on Smart Materials Applications

Chougule, Sandip^1 ; Sheed, Digvijay^1 ; Prabhu, N.^2 ; Kashyap, B.P.^2 ; Jha, Kaushal^3 ; Singh, R.K.P.^1

Bharat Forge, Kalyani Centre for Technology and Innovation, Pune

411036, India^1

Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai

400076, India^2

Engineering Design and Development Division, BARC, Mumbai

400085, India^3

关键词: Acicular alpha;    Differential strain;    Dynamic recrystallization (DRX);    Equiaxed alpha;    Flow properties;    Multi-pass friction stir processing;    Strain rate sensitivity index;    Ti-6Al-4V alloy;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/422/1/012017/pdf
DOI  :  10.1088/1757-899X/422/1/012017

来源: IOP

【 摘 要 】

Multipass friction stir processing (MFSP) of the Ti-6Al-4V alloy was carried out at 600 tool rpm and 80 mm/min traverse speed. After first pass, the initial elongated α structure transformed to prior β grains, consisting of a mixture of acicular α'and very fine lamellar α colonies along with α layer grain boundary in stir zone (SZ). This subsequently transformed to equiaxed α grain via dynamic recrystallization (DRX) process. With the increase in the number of FSP passes the fraction of equiaxed α grains was found to increase, reaching almost fully equiaxed α structure in SZ upon completion of the fifth pass. Flow properties of MFSP Ti-6Al-4V alloy were investigated by differential strain rate test carried out at 927°C. There appears no significant variation in the strain rate sensitivity index (m ≥ 0.3) values between as received Ti-6Al-4V alloy and MFSP Ti-6Al-4V alloy specimens.