Title: TRIZ approach for machining process innovation in cryogenic environment
Authors: Jaharah A. Ghani; A.R. Natasha; C.H. Che Hassan; J. Syarif
Addresses: Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia ' Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia; Department of Manufacturing and Materials, Faculty of Engineering, International Islamic University Malaysia, P.O. Box 10, 50728 Kuala Lumpur, Malaysia ' Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia ' Department of Mechanical Engineering, College of Engineering, University of Sharjah, P.O. Box 27272, Sharjah, UAE
Abstract: This paper presents the utilisation of TRIZ approach in machining process of AISI 4340 in cryogenic environment which lead to product improvement in turning process. The machining study is carried out in two stages; FEM simulation for finding the optimum condition and machining experiment to visualise the product improvement that involved plastic deformation. The simulation result revealed that at moderate to high cutting speed, high feed rate and high depth of cut will result in high temperature that enable for the change in phase of AISI 4340 from retained austenite to fully martensite. A sample from machining experiment at optimum cutting condition found that the microstructure changes beneath the machined until at the depth of ~7 µm with high hardness to 8,500 N/mm2 Martens hardness at the machined surface. This hardness is equivalent to the hardness obtained in conventional case hardening process that is required after the machining of AISI 4340 in their application as automotive engine parts in order to enhance these parts in their service lives. This study reveals that the TRIZ approach helps to systematically analyse the various outcomes in this study started with process limitation, problem identification, axiomatic and Su-field analysis.
Keywords: TRIZ; machining; process innovation; product improvement; cryogenic turning; hardness; cryogenics; AISI 4340 alloy steels; FEM; finite element method; simulation; cutting speed; feed rate; depth of cut; temperature; austenite; martensite; microstructure; automotive components; engine parts.
International Journal of Materials and Product Technology, 2016 Vol.53 No.3/4, pp.286 - 297
Received: 04 Feb 2016
Accepted: 31 Mar 2016
Published online: 22 Sep 2016 *