Friction drilling is a non-traditional hole achieving method that is a clean, chip-less process, which is called thermal drilling, form drilling, flow drilling, and friction stir drilling. In this study pre-drilling friction drilling was investigated for improving the bushing shape of A7075-T651, which is a brittle cast material. During the process, surface roughness and bushing shapes were analyzed and generated frictional heat was measured by the virtue of thermocouples. Experiments were carried out to 4 mm and 6 mm in thicknesses of A7075-T651 aluminum alloy at 1200, 1800, 2400, 3000, and 3600 rpm spindle speeds, 20, 40, 60, 80, and 100 mm/min feed rates with using high-speed steel rotating conical tool, whose diameter is 8 mm. Consequently, the bushing shapes were advanced without cracks and petal formation in pre-drilling Friction drilling in comparison with without pre-drilling process. With increasing pre-drilled hole diameter the generated frictional heat was decreased. The achieved temperature was realized to be 1/2–1/3 of the melting temperature of the workpiece. Surface roughness values were decreased with decreasing or increasing both spindle speed and feed rate correspondingly.

“Grinding Mechanism having Advanced Secondary Rotational Axis” is one of the newer plane surface grinding methods that has an uncommon abrasion mechanism. Unlike conventional methods, in Grinding Mechanism having Advanced Secondary Rotational Axis, there are two rotations of a wheel. The first rotation is the same as the conventional grinding methods, which is the circumferential rotation. The other rotation is the newly developed axial rotation, where the wheel rotates around itself perpendicular to its radial axis. In the grinding process, the grinding force, energy, power, and temperature are directly related to the material removal rate. In this article, the chip model in Grinding Mechanism having Advanced Secondary Rotational Axis was addressed and material removal rate was reformulated. The new chip ratio formula was adapted to the grinding force, energy, power, and temperature in the conventional plane surface grinding method. The chip formed in the conventional plane surface grinding method consists of two-dimensional xy plane. In Grinding Mechanism having Advanced Secondary Rotational Axis, on the other hand, the chips consist of three-dimensional xyz plane. The reason behind this is the second rotation obtained in Grinding Mechanism having Advanced Secondary Rotational Axis (axial rotational motion). The chip model was obtained from the combination of two rotations in Grinding Mechanism having Advanced Secondary Rotational Axis. As a result, the resulting chip model increased the material removal rate only slightly and this increase was negligible. Accordingly, an increase in grinding force, energy, power, and temperature was observed at negligible rates.

Drilling is a widely used production method, having a broad range of applications taking part in machining operations. The length of the cutting edge of the drill causes variations in cutting speed, resulting in undesired outputs. In order to decrease this adverse impact in drilling, selecting higher point angles is an obligation, associated with three different kinds of feed rates and spindle speeds. The aim of this study is to investigate the effect of feed rate, spindle speed, and point angle on the fluctuation size in thrust force besides the effect of the fluctuation size in thrust force on the surface roughness, tool wear and chip morphology. In conclusion, while higher point angles provided optimum outputs such as lower fluctuation size in thrust force, less tool wear, better surface quality and continuous chip form, the effect of feed rate and spindle speed on these outputs varied depending on each other. With the stability in fluctuation size in thrust force, less tool wear took place, and better surface quality and continuous chip form were achieved. However, due to the effect of vibrations, higher fluctuation size in thrust force caused undesired outputs, such as poor surface quality, more tool wear, removal chip in short and brittle form during the drilling operations.

Machinability, especially turning process, is a significant manufacturing method, but the vibrations, arisen from the natural mechanism of the process, make difficulties. Unnumbered parameters influence the process outcomes such as surface roughness, chip morphology, and vibration amplitudes. In the present paper, the effect of tool approach angle and chip slenderness ratio (CSR) on the vibration amplitudes, StDev in vibrations, and chip morphology were investigated. For this purpose, 15o, 30o, and 45o approach angles, 1, 3, 5, 10, and 15 CSR also depending on CSR values 0,1 mm/rev, 0,15 mm/rev, 0,45 mm/rev, and 0,5 mm/rev feed rates, 0,5 mm, 1 mm, 1,5 mm, and 2,25 mm cutting depths were selected. It was investigated that according to both vibration amplitudes and chip morphology criterion, the most appropriate cutting tool approach angle was 30o, and CSR values were 10 and 15. Besides, as the tool approach angle progress, the vibration amplitudes in the X (cutting depth) direction were deteriorated, but at small CSR values, they were increased. The optimum feed rates were to be 0,1 mm/rev and 0,15 mm/rev, but the influence of the cutting depth showed differences depending on the values of the selected feed rates. Surface quality was improved at 30o and 45o approach angles, 0,1mm/rev and 0,15 mm/rev feed rates and10 and 15 CSR values. The chips in lamellas form, without severe deformation cracks and serration formation were observed at 30o approach angle, 0,1 mm/rev and 0,15 mm/rev feed rates also at 10 and 15 CSR values.