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REV. DE CIÊNCIA & TECNOLOGIA, Piracicaba, v. 11, n. 21, p. 1-73, jan./jun. 2003.R EVISTA DE C IÊNCIA& T ECNOLOGIA • 211COMISSÃO EDITORIALN IVALDO L EMOS C OPPINI – presidente (Engenharia de Produção) K LAUS S CHÜTZER (Engenharia Mecânica)N ELSON C ARVALHO M AESTRELLI (Gestão da Produção)N IVALDI C ALONEGO JÚNIOR (Ciência da Computação)SÔNIA M ARIA M ALMONGE (Engenharia Química)COMITÊ CIENTÍFICOB ERT L AUWERS (Katholieke Universiteit Leuven –Bélgica)C ARLOS A LBERTO G ASPARETTO (Facens/Unicamp –ESTEVAL project partners.– Feature Based Integrated Design Environment.Identification of interdependencies between manufacturing features.Unsuitable finishing quality (Schützer et al., 1999).After considering several possibilities, which could result in this poor surface quality cutting tool geometry , clamping and balancing of the tool system, technological parameters and machining set-ups, it was realized, that the problem came from the CNC of the machine tool, which was incapable of processing the NC program as fast as the feed rate defined in the NC program. So the machine reaches the point refereed in one line of the program and the information to move the tool to the next point was not processed yet, then the machine had to wait a couple of milliseconds to start moving again.This incompatibility between the feed rate defined in the NC program and the processing time of the CNC results in two different situations according to the CNC used:poor surface quality – the CNC tries to move the machine at the programmed feed rate, but it can-Improper surface finishingThe workpiece used and the finishing tool path.The roughing and semi-finishing operations were accomplished using exactly the same technological parameters and cutting strategies for all workpieces.The comparison analysis was done only during the finishing operation and the same technological para-meters, cutting strategies and tools were used in both cases. The finishing operation was distinguished by the methodology of interpolation. The trajectory of the finishing tool path is shown in figure 3. For this operation it was used a 10 mm ball end mill tool at 10000 rpm and the programmed feed rate was 2000 mm/min.YSISThe results of the machining experiments considering the NC program size, the time required to exe-cute the program and the surface quality in terms of roughness and superficial texture were compared and the conclusions are presented below.NC Program SizesThe table 2 presents the finishing programs sizes calculated for both methods. It proves that less infor-mation are required to describe tool paths by the circular/linear method, thus reducing the program size byMETHOD P ROGRAM SIZE N UMBER586 kbCircular/linear83 kb• V. 11, Nº 21 – pp. 29-36Regions where the feed rate as reduced.2000 mm/min660 mm/min 1500 mm/min700 mm/min2000 mm/minRoughness AnalysisIt was used a digital Surftest Equipment to obtain the Ra and Rz parameters. It was analyzed the same areas for all workpieces. Practically, there are not differences between the roughness parameters for both interpolation methods.Surface T exture AnalysisIt was possible to visually verify the differences between the surfaces of both methods. The circular/ linear workpieces are smoother than the linear ones. The figure 5 shows this texture.Irregular surface texture Regular surface textureBesides those transversal marks at the workpiece machined by the linear interpolation, this method also gives a deficient quality in the longitudinal direction, as it is seen in the next photos taken by a CCD camera connected in an microscopy.Figure 6 was taken using a microscopy with magnification 10x of the linear part. The vertical marks are the cusp heights left by the ball end mill tool. The steps-over of the tool path is on the horizontal direc-Fig. 6. Uneven cusps from a linear workpiece.Fig. 7. Even cusps from a circular/linear workpieceIn linear interpolation method is possible to see uneven cusp heights, what can difficult drastically the hand finishing afterwards. This problem is not seen at the workpieces milled by the circular/linear method, as shown in figure 7. It happens due to the more constant cutting movements.In this method, the cusps height are much more uniform, what can help the manual finishing afterwards, by decreasing this process time, and improving the accuracyCONCLUSIONThe High Speed Cutting T echnology can be attractively applied in die and mould manufacturing, among others applications. However, there are several other technologies in the process chain that must be considered to support an efficient HSC process.R EVISTA DE C IÊNCIA & T ECNOLOGIA • V. 11, Nº 21 – pp. 29-36。