Usinagem de ferro fundido vermicular com ferramenta de corte à base de alumina magnésio

• Autor(a) principal: Sousa, Taíse Azevedo de
• Data de Publicação: 2020
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/192492
• topic: Usinagem; Ferro fundido; Material Cerâmico; Ceramic tools; Hard metal; Dry machining; Vermicular Cast Iron

The development of new materials is extremely important, due to the need to obtain materials with good properties and low cost. There is a continuing need to improve tools for machining materials that have high strength at elevated temperatures that meet the vermicular cast iron. Small advances in the development of new tools could mean important aspects in the field of machining, in addition to making the market more competitive. The set of production and application of ceramic cutting tools in the machining processes of vermicular cast iron (GJV450) needs further advances, being an object of great industrial interest. In this context, the present work determined the best application condition of the ceramic tools based on Alumina (Al2O3), doped with magnesium oxide (MgO) on a laboratory scale, in the machining without cutting fluid of the vermicular iron class GJV450 in comparison with a commercial carbide tool coated with alumina, based on the need for machining vermicular cast iron in industries and foundries. For turning vermicular cast iron with a ceramic tool, the parameters used were cutting speeds of 300-350-400-450-500-550-600-650 m / min; feed of 0.1-0.3 mm / rev and machining depth of 0.5 -1.0 mm and for the carbide tool, cutting speeds of 150-250-350-450 m / min; feed rate of 0.1-0.3 mm / rev and machining depth of 0.5 -1.0 mm. The previously defined input variables (Vc, f, ap), were correlated with the output variables such as roughness (Ra and Rt), power, acoustic emission, flank wear (Vb) and vibration. Taguchi design of experiments was used with the definition of smaller is better, one can evaluate the effects of the input factors that affected the response variables. It was found that the advance (f) is an influential factor with a tendency for growth except for the acoustic emission, power, and vibration for carbide. For ceramics, the feed (f) was influential except for the power and flank wear. The ceramic alumina tool presented better machining conditions in terms of flank wear, with a cutting speed Vc = 350 m / min, while the carbide showed a better condition with cutting speed Vc = 150 m / min. The wear mechanisms were analyzed and for ceramics, the wear was predominantly abrasive and, in the carbide, the diffusive mechanism occurred, the machining conditions were favorable to the use of the ceramic tool.