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In this study, milling of a carbon-fiber-reinforced polymer composite material (CFRP) was investigated experimentally using various carbide end mills. The input parameters included the spindle speed, feed rate and cutting tool, whereas the output parameters were defined as the cutting force and surface roughness. The experimental design was based on the Taguchi L18 (6 1 ×3 2 ) orthogonal array. In the tests, six different carbide end mills with a 10 mm diameter were used: an uncoated two-flute 30°helix-angled one; carbide-coated two-, three-and four-flute 30°helix-angled ones; and TiAl-coated three-and four-flute 45°h elix-angled ones. The cutting parameters included three different feed rates (0.03, 0.06, 0.09) mm/tooth and three different spindle speeds (3800, 4800, 5800) min -1 . The Taguchi method was applied to select the most appropriate cutting parameters (cutting force, feed rate) for the tests. With the analysis of variance (ANOVA), the feed-rate factor was found to be the most effective one among these parameters (cutting forces and surface roughness). The results of the experiments showed that the uncoated carbide end mill had a better performance in terms of the cutting forces and surface roughness. Besides, it was also seen that the surface roughness increases with the increasing number of flutes and helix angle. Keywords: CFRP, cutting forces, surface roughness, Taguchi method, ANOVA V {tudiji je bil eksperimentalno prou~evano rezkanje polimernega kompozitnega materiala, oja~anega z ogljikovimi vlakni (CFRP) z uporabo rezkarjev z razli~nim karbidnimi nanosi. Vhodni parametri so vklju~evali hitrost vrtenja vretena, hitrost podajanja in rezalno orodje, medtem ko sta bila izhodna parametra sila rezanja in hrapavost povr{ine. Zasnova eksperimenta je temeljila na Taguchi L18 (6 1 ×3 2 ) ortogonalni matriki. Pri preskusih je bilo uporabljenih {est razli~nih cilindri~nih rezkarjev s premerom 10 mm, dvorezni s kotom spirale 30°brez nanosa, dvo, tri in {tirirezni s kotom spirale 30°prekriti s karbidi ter tri-in {tirirezni rezkar s kotom spirale 45°in nanosom TiAl. Uporabljeni parametri rezanja so vklju~evali tri razli~ne hitrosti podajanja (0.03, 0.06, 0.09) mm/zob in tri razli~ne hitrosti vrtenja vretena (3800, 4800, 5800) min -1 . Za izbiro najprimernej{ih uporabljenih parametrov (sila rezanja, hitrost podajanja), je bila uporabljena Taguchi metoda. Med uporabljenimi parametri (sila rezanja in hrapavost povr{ine) se je pokazalo, s pomo~jo analize variance (ANOVA), da je hitrost podajanja najbolj vpliven faktor. Rezultati preskusov so pokazali, da ima rezkar brez nanosa karbida, bolj{e zmogljivosti glede na sile rezanja in hrapavost povr{ine. Poleg tega se je pokazalo, da hrapavost povr{ine nara{~a z ve~anjem {tevila utorov in kota vija~nice.

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Al-7Si, Al-7Si-4Zn, Al-7Si-4Zn-3Cu alloys were produced by permanent mold casting method to investigate the effects of copper and zinc additions on the machinability properties of Al-7Si alloy. The structural and mechanical properties of the produced alloys were investigated with conventional methods. Machinability properties of these alloys were determined by turning, and they were associated with structural and mechanical properties of the alloys. Machinability experiments were carried out in CNC vertical machining center under dry cutting conditions using uncoated carbide drill and constant cutting speed (120 m/min), feed (0.15 mm/rev) and depth of cut (15 mm) values. The microstructure of Al-7Si binary alloy was observed to be composed of aluminum-rich α phase, primary silicon crystals and eutectic Al-Si phase. The addition of 4% Zn to the Al-7Si alloy did not form a different phase in the microstructure. However, Al 2 Cu intermetallic phase was formed by addition of 3% Cu. While the hardness and tensile strength of the alloy increased, elongation to fracture significantly reduced. As a result of machinability experiments, it was observed that the minimum thrust force and surface roughness occurred in Al-7Si-4Zn-3Cu alloy, while the maximum built-up edge was observed during drilling of Al-7Si and Al-7Si-4Zn alloys. Microhardness value of machined surface in Al-7Si alloy was found to be the minimum while the maximum Al-7Si-4Zn-3Cu alloy was observed.

In this study, by cutting electrical steel stator laminations, one of the most important components of electrical machines by different cutting methods, the effects of these cutting methods on motor efficiency are investigated. As cutting methods, wire electrical discharge machining, punching, laser and abrasive water jet methods are used. Burr formation at the cutting edge leads to short circuits during the steel packaging and causes magnetic losses in steel packages to increase. In addition, depending on the cutting methods, electrical steel lamination insulation layer is damaged as a result of residual and thermal stress formations. These negative conditions cause iron, friction and windage, stator, rotor and additional load losses occurred in the engine to decrease. In order to minimize these cases, electrical steel stator laminations are cut with the cutting parameters determined as a result of pre-cut tests and 5.5-kW induction motors are manufactured. These manufactured motors, according to IEC 60034-2-1-1B method, are subjected to no-load performance tests in addition to six different loading ratios of 25%-50%-75%-100%-115%-125% and constant 50 Hz frequency. As a result of the test measurements, losses occurred in electrical steels cut with abrasive water jet are found to be higher than the other cutting methods. In addition, in terms of the motor performance, the best results are obtained with wire electrical discharge machining cutting method.

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