High-speed drilling mechanism study of unidirectional CoCrFeNiAl fiber-reinforced aluminum matrix composites

Fiber-reinforced aluminum matrix composites have a wide range of application prospects in aerospace, automotive, and other fields. In order to further optimize the processing technology and improve the processing efficiency, the high-speed drilling mechanism of FeCoNiCrAl high-entropy alloy fiber-reinforced 7050 aluminum matrix composites was investigated in this study. A composite plate composed of three-layer unidirectional fiber-reinforced composite was constructed by using ABAQUS finite element software. The effects of different bit geometry parameters and drilling parameters on drilling force, stress-strain, and subsurface damage were studied during high-speed drilling. The results show that the drilling force is positively correlated with the feed speed and decreases with the increase of the spindle speed. The drilling force is positively correlated with spiral angle and negatively correlated with top angle. With the increase of feed speed, the area of the height stress area of the inlet and outlet increases first and then decreases, and the maximum point is 450 mm/s and 400 mm/s, respectively. With the increase of spindle speed, the area of the entrance layer increased first and then decreased. The area of the entrance layer was the largest when the spindle speed was 600 r/s, and the area of the outlet layer increased with the spindle speed. When the screw angle is 40 degrees and the top angle is 90 degrees, the main cutting edge of the bit drills out the whole plate, the processing quality of the drilling is relatively best. With the increase of spiral angle, the subsurface damage range of fiber at the inlet and outlet layer decreases. As the top angle increases, the damage range increases first and then decreases, showing a peak trend. With the increase of feed speed, the damage range decreases first and then increases. The damage range increases significantly with the increase of spindle speed.