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Hybrid 3D Modelling of Parts
Published in Ionuţ Gabriel Ghionea, Cristian Ioan Tarbă, Saša Ćuković, CATIA v5, 2023
Ionuţ Gabriel Ghionea, Cristian Ioan Tarbă, Saša Ćuković
In the Type area, the user enters the values of 60 and 200 mm in the Pitch and Height fields, respectively. The Orientation list will contain the Counterclockwise option, and the two fields, Starting Angle and Taper Angle, remain at the default values of 0°, because the helix starts from Point.2 and its type is cylindrical. The Taper angle, for values other than 0°, creates a conical helix. Figure 3.133 shows the helix parameters setting dialog box, the Revolute.1 surface and the helix drawn around the Y axis.
Drilling of titanium alloy (Ti6Al4V) – a review
Published in Machining Science and Technology, 2021
Chua Guang Yuan, A. Pramanik, A. K. Basak, C. Prakash, S. Shankar
It was reported that the ultrasonic vibration drilling is effective to make fine hole or in drilling of difficult to machine materials. However, the vibration amplitude is realized up to several micro-meters or so it restricts the machining efficiency in ultrasonic vibration drilling. Instead, LFVAD achieves better machining efficiency (Okamura et al., 2006). Okamura et al. (2006) reported that the temperature, tool wear, and the exit burr height and thickness during drilling of titanium alloy reduced significantly through a low-frequency vibration with 0.4 mm and 30-Hz amplitude and frequency, respectively. The chips were appeared as short length and conical helix types. As the amplitude becomes large and the vibration frequency becomes high, these effects appear more remarkably. Okamura and Sasahara (2017) also established equations to calculate cutting tool temperature during LFVD of titanium alloy. The temperature transition was simulated from the cutting energy estimated from the machining speed and force. The machining temperatures for LFVD are lower than those of CD. The changes of undeformed chip thickness caused recurrent rise and fall of temperature, which are different for different frequency of vibration. Hussein et al. (2019) applied a frequency of 2.5 oscillation/rev (83.5 and 125 Hz) and noted that greater amplitude doubled the uncut chip thickness, which contributed to the amount of applied force and temperature to the cutting system as a cyclic impact energy. However, the machining temperature reduced (35.8%) substantially due to change machining mode from continuous to interrupting cutting. The improved chip evacuation efficiency reduced the size error of the hole and reduced the surface roughness by 50%. On the other hand, lower amplitude reduced surface and subsurface defects significantly. LFVAD induced compressive residual stress as high as 242 MPa in 93 μm deep at higher amplitude (0.48 mm), which contributes higher fatigue life to the machined parts.