Title: The effectiveness of palm oil methyl ester as lubricant additive in milling and four-ball tests

Authors: Willey Yun Hsien Liew; Sebastian Dayou; Jedol Dayou; Nancy J. Siambun; Mohd. Azlan Bin Ismail

Addresses: School of Engineering and Information Technology, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu, Sabah, 88400, Malaysia ' School of Engineering and Information Technology, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu, Sabah, 88400, Malaysia ' Energy, Vibration and Sound Research Group (e-VIBS), School of Science and Technology, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu, Sabah, 88400, Malaysia ' School of Engineering and Information Technology, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu, Sabah, 88400, Malaysia ' School of Engineering and Information Technology, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu, Sabah, 88400, Malaysia

Abstract: This paper examines the effectiveness of palm oil methyl ester (POME) as lubricant additive using the four-ball and milling tests. In milling 55 HRC-stavax® (modified AISI 420 stainless steel) under flood lubrication, three stages of tool wear occurred: 1) initial wear by delamination, attrition and abrasion; 2) cracking at the substrate, 3) followed by formation of individual surface fracture at the cracks which would then enlarge and coalesce to form a large fracture surface. Mineral oil sprayed in mist form was more effective in reducing the coating delamination and delaying the occurrence of cracking and fracture. The effectiveness of mineral oil in suppressing these wear modes could be enhanced by the presence of POME. The mechanism by which the POME suppressed these wear modes could be explained by the results obtained in the four-ball tests which showed that the presence of POME as additive in the mineral oil reduced the friction coefficient, severity of welding and increased the critical load for welding to occur.

Keywords: stainless steel; lubricant additives; cutting tools; palm oil methyl ester; POME; milling tests; four-ball tests; flood lubrication; tool wear; mineral oil mist; wear modes; friction coefficient; welding severity; critical load.

DOI: 10.1504/IJSURFSE.2014.060482

International Journal of Surface Science and Engineering, 2014 Vol.8 No.2/3, pp.153 - 172

Received: 30 Jan 2013
Accepted: 03 Jul 2013

Published online: 17 Apr 2014 *

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