Title: Machinability of compacted graphite iron (CGI) and flake graphite iron (FGI) with coated carbide
Authors: Varun Nayyar; Gustav Grenmyr; Jacek Kaminski; Lars Nyborg
Addresses: Department of Materials and Manufacturing Technology, Chalmers University of Technology, Hörsalsvägen 7B, SE-41296, Gothenburg, Sweden ' Sandvik Tooling Sverige AB, 1521, 811 81 Sandviken, Sweden ' Department of Materials and Manufacturing Technology, Chalmers University of Technology, Gothenburg, SE–41296, Sweden ' Department of Materials and Manufacturing Technology, Chalmers University of Technology, Gothenburg, SE-41296, Sweden
Abstract: Compacted graphite iron (CGI) has an important role in manufacturing of new generation engines. Better strength of CGI, as compared to flake graphite iron (FGI), allows CGI engine to perform at higher peak pressure, higher fuel efficiency and lower emission rate. However, the machinability of CGI is as poor as compared to FGI. The machinability of CGI is an area that needs to be studied in a better way to cut the production cost of the engine. It is a well known fact that the as-cast engine block has varying microstructure and mechanical properties due to different cooling rates at different locations of such a geometrically complex component. This has highlighted the need for studying machinability as a function of microstructural and mechanical properties so that the machining process could be optimised. For this reason, machinability of 18 different types of CGI materials along with two FGI materials has been studied, in terms of cutting force and tool life, in a turning operation in this work.
Keywords: compacted graphite iron; CGI; flake graphite iron; FGI; tool life; cutting force; turning; machinability; microstructure; mechanical properties; tool wear; engine manufacture; coated carbide; engine blocks.
International Journal of Machining and Machinability of Materials, 2013 Vol.13 No.1, pp.67 - 90
Received: 23 Jun 2011
Accepted: 30 Nov 2011
Published online: 05 Feb 2013 *