ISSN: 1003-6326
CN: 43-1239/TG
CODEN: TNMCEW

Vol. 27    No. 4    April 2017

Machining characteristics of fine grained AZ91 Mg alloy processed by friction stir processing
G. V. V. SURYA KIRAN1, K. HARI KRISHNA1, Sk. SAMEER1, M. BHARGAVI1, B. SANTOSH KUMAR1, G. MOHANA RAO1, Y. NAIDUBABU1, RAVIKUMAR DUMPALA2, B. RATNA SUNIL1
(1. Department of Mechanical Engineering, Rajiv Gandhi University of Knowledge Technologies (AP-IIIT), Nuzvid 521202, India;
2. Department of Mechanical Engineering, Visvesvaraya National Institute of Technology, Nagpur 440010, India
)
Abstract: AZ91 Mg alloy was considered and friction stir processing (FSP) was adopted to achieve grain refinement to investigate the effect of grain size and secondary phase on machining characteristics during drilling at various speeds and feeds. Super saturated AZ91 Mg alloy was obtained after FSP and the grain refinement was achieved from (166.5±8.7) μm to (21.7±13.5) μm. Surprisingly, hardness reduced for FSP AZ91 Mg alloy (88.95±6.1) compared with AZ91 alloy (108.2±15.6), which was attributed to the reduced secondary phase. However, the mean cutting force for FSP-treated (FSPed) AZ91 Mg alloy was marginally increased. The edge damage of the drilled holes was lower for FSPed AZ91 Mg alloy compared with unprocessed AZ91 Mg alloy. Hence, it can be understood that the grain refinement may slightly increase the cutting forces during drilling but better edge finishing can be achieved in machining of AZ91 Mg alloy.
Key words: magnesium alloy; friction stir processing; machining; grain size; microstructure
Superintended by The China Association for Science and Technology (CAST)
Sponsored by The Nonferrous Metals Society of China (NFSOC)
Managed by Central South University (CSU)