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Titanium in industrial applications has been described as costly material and difficult to manufacture. But, Ti alloys have been commonly used in aerospace constructions and implant production because of its specific properties. Machining difficulties are taken place incase of the manufacturing of Ti alloys by casting method. Powder metallurgy method for part production from Ti alloys is preferred for minimizing of production costs and machining difficulties. For this aim, Ti-6Al-4V, Ti-5Al-2,5Fe and Ti-6Al-7Nb alloys using in biomaterials and aerospace industries were produced from elemental powders by pressing at 530 MPa and sintering at 1250°C temperature at protective argon gas atmosphere under 10-4 torr vacuumed. Pores structure, sinter neck formation, and widmanstatten structures were investigated experimentally. In order to determine of effect of the pores structure on wear and bending strength, wear and bending tests were performed. As a result, bigger porous and lower sinter neck formation of Ti-6Al-7Nb alloy than other Ti alloys decreased the wear strength and bending strength. [ABSTRACT FROM AUTHOR]

In this study, wear performance of cast copper alloyed with ferromanganese powder was determined by wear experiments. Surface of the specimens produced by cast copper were alloyed with 9 g ferromanganese powders using 115 A, 125 A and 140 A current intensities applied by Gas Tungsten Arc (GTA) Method. Wear experiments were carried out using different loads 20, 40 and 60 and sliding distances. The wear characteristics were measured with weight loss. Fuzzy logic model was setup according to experimental results. Current intensity, applied load and sliding distances were assigned as inputs and then wear amount was designed as output in this fuzzy logic model. Based on experimental results, system input and output membership functions were determined. Output support range was investigated in eight groups to be able to make sensitive estimates. It is found that estimated wear amount with the use of the proposed system be very close to experimental wear results thanks to regration analyses (R2 correlation values). For untested conditions wear performance characteristics could be determined with an application of the proposed fuzzy logic model of the investigated alloys. [ABSTRACT FROM AUTHOR]

In this study, cutting force of circular diamond saw in marble cutting industry was modeled using fuzzy logic method. Different cutting forces are effective during cutting processes and saw is damaged by these forces. Monitoring and controlling of the forces is important for cutting machine and circular diamond saw life and its influence the work-piece quality. Monitoring of cutting forces during cutting process can be provided with an expert and electronic system. According to literature experimental studies in fuzzy model, the specific removal rate, depth of cut and feed rate were assigned as input values and cutting force was designed as out value. Most convenient membership functions and support range were selected for each input-output parameter. Relations between memberships functions were established according to expert knowledge obtained from the literature experimental results. Cutting force values were predicted according to input values in the fuzzy model. Fuzzy model was verified by predict value which was compared with the literature experimental value. As a result, output values obtained from fuzzy system were compatible with experimental results and it was exposed that cutting forces were estimated without marble cutting tests. [ABSTRACT FROM AUTHOR]