Authors: Wilson Luis Guesser; Fernando Souza Pereira; Lourival Boehs
Addresses: Depto Eng Mecânica and Tupy, UDESC, Rua Albano Schmidt, 3400, ZIP: 89227-901, Joinville, SC, Brazil ' Depto Eng Mecânica, Centro Tecnológico, UFSC, ZIP 88040-900, Florianópolis, Brazil ' Depto Eng Mecânica, Centro Tecnológico, UFSC, ZIP 88040-900, Florianópolis, Brazil
Abstract: The surface quality and the material near the surface are changed due to stresses induced by the machining process. In this work, surface and subsurface changes caused by turning of grey iron are studied. It was verified the formation of marks caused by the advancing edge of the cutting tool, material override, presence of debris on the surface and micro pores left by the fracture and pullout of graphite flakes. Thus, the surface roughness of the part is the result not only of the marks left by the cutting tool but also from the deformation and micro fractures that this surface undergoes during machining. In the region just below the machined surface it was observed intense plastic deformation of pearlitic matrix, causing thinning and expulsion of graphite through the surface and morphology change of sulphide particles. The implications of these surface features on the performance of the part are discussed.
Keywords: machining; turning; surface changes; grey cast iron; surface integrity; surface quality; grey iron; surface roughness; cutting tools; microfractures; microcracks; plastic deformation; pearlitic matrix; graphite; morphology; sulphide particles.
International Journal of Machining and Machinability of Materials, 2016 Vol.18 No.3, pp.313 - 324
Received: 24 Apr 2015
Accepted: 14 Nov 2015
Published online: 30 Apr 2016 *