Analysis on the tool wear behavior of 7050-T7451 aluminum alloy under ultrasonic elliptical vibration cutting

Abstract

The machinability and tool wear behavior of 7050-T7451 aluminum alloy versus cutting parameters and vibration frequency are compared between conventional cutting (CC) and ultrasonic elliptical vibration cutting (UEVC) processes. A single-factor dry cutting experimental scheme is designed in light of the kinematic property of UEVC. The microstructural evolution in the cutting-layer metal are observed for different cutting parameters and vibration frequencies and the effects of these parameters on the tool wear behavior are investigated for both CC and UEVC. The results indicate that under the same cutting parameters, UEVC requires about three fifths the cutting force required by CC and provides a much higher cutting surface quality than CC. The cutting surface by UEVC shows visible precipitate-free zones (PFZs); the width and intermittent degree of the PFZs are obviously regionalized with vibration frequency, with a critical vibration frequency of 20,000 Hz. For CC, tool wear occurs typically in forms of tipping, spalling wear, or severe adhesive or oxidative wear, whereas for UEVC, tool wear typically mainly consists of impact-induced mechanical wear such as abrasive wear, mild oxidative wear and mild adhesive wear.