The present work deals with temperature effects and parametric optimization in the drilling of continuous glass fiber reinforced epoxy composite. Drilling ability was examined operating a drilling system with different drill bits, feed rate, and spindle speed parameters. The investigation was performed by changing the tool and composite interface. Drilling experiments were carried out under the dry condition. Thrust force and drilling temperatures were measured using dynamometer and thermal camera. Peel-up and push-out delamination were evaluated using an image analyzing tool. Results show that the tribo-mechanical behavior of the drilling operation is affected at different levels by tool coating. This behavior is related to the intrinsic friction properties of coating nature. Response surface methodology was used in the evaluation of experiment results. The feed rate of 0.13 mm/rev, spindle speed of 2425 rpm and HSS-TiN drill bit are found as an optimum drilling parameters and drill type.

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The purpose of this study is examining the effects of ultrasonic melt treatment on microstructure and mechanical properties of the AlSi10Mg alloy. In this study, ultrasonic melt treatment with different frequencies and duration was applied to AlSi10Mg molten alloy. Also, T6 heat treatment was applied to samples which were obtained by ultrasonic melt treatment (UST) with different application parameters to investigate the combination of T6 heat treatment and UST effect on the microstructure and mechanical properties. The microstructure of cast samples was characterized by optical and scanning electron microscopy. Also, hardness and tensile tests were carried out. The results indicate that primary α-Al phases are transformed from coarse dendrites to smaller dendrites by the ultrasonic melt treatment. Besides, secondary dendrite arm spacing of the alloy decreased and mechanical properties such as hardness and tensile strength increased. UST reduces the secondary dendrite arm spacing (SDAS) of the aluminum alloy to 50 %. Additionally, increasing treatment time contributes to hardness up to 12 % and tensile strength up to 50 %.

The main objective of this study is to examine the machinability and the surface quality conditions of the AA7075 material with different temper conditions. For this purpose, various temper treatments are implemented to evaluate the impact of microstructural properties on tool wear and the surface quality of the drilled holes. The drilling operations have been done on 0, F, T4, T6, and T7 temper conditions. Process parameters were three different spindle speeds (715, 1520, and 3030 rev/min) and three feed rates (0.1, 0.2, and 0.3 mm/rev) with HSS-G highperformance ground standard twist drill bit. The present work deals with the effects of temper conditions on thrust force, drilling temperature, tool wear, surface integrity, and chip morphology. Response surface methodology was used in the evaluation of experiment results. The optimization results showed that while thrust force and torque are not significantly affected by a change in spindle speed, they are sensitive to an increase in feed rate. Heat-generation on the drill bit is the lowest at low levels of both the feed rate and spindle speed parameters. The AA7075-T6 condition specimen was machined with continuous chip formation, resulting in the best hole surface quality. The 3D finite element modeling of the drilling process was carried out, and the drilling performance of AA7075-T6 was evaluated in terms of thrust force, heat generation, and chip formation.

Fiber-reinforced plastics are known as advanced composite materials thanks to their high strength and lightweight features. Carbon fiber reinforced polymers (CFRPs) are one of the high-performance and high-cost fiber-reinforced polymer (FRPs) materials. They are used in several high-performance engineering applications such as motorsports, marine, aviation, energy and defense industry. The cost of carbon fiber is higher compared to many other materials, more competitive and cost-effective productions will spur the demand for composite parts exponentially. Thus, hybrid laminate composite containing carbon and glass fiber materials were manufactured as an alternative for CFRP materials. Because using glass fiber prepreg instead of carbon fiber prepreg will lead the material to become cheaper. However, machining of the FRP materials is still an important issue. For this reason, the present study is focused on the mechanical and machining performance of the polymer hybrid and carbon fiber epoxy composites.