Machinability analysis of difficult-to-cut material during ultrasonic vibration-assisted ball end milling

ABSTRACT

Vibration-assisted machining has been proven as an excellent material-removal process with its multiple advantages over ordinary machining methods. However, the process is usually applied for the machining of easy-to-cut materials and conventional cutting tools vibrating, at or below the ultrasonic frequency. This study was conducted to evaluate the effect of ultrasonic vibration of the ball end mill with the objective to enhance the machinability of difficult-to-cut material. An analytical model was established to calculate the cutting forces generated during the process. A WC-Co-based ball-nose end mill with a TiAlSiCrN coating was used to perform the machining tests on tool steel (AISI-H13). Machinability was evaluated in terms of cutting forces, chip morphology, rate of wear, and surface integrity. During the machining experiments, cutting forces under the effect of tool vibration were found to be reduced with the improvement in machined surface quality. The obtained results indicate the overall enhancement in the machinability of the work material and hence the technique can be applied to substitute the conventional milling.

KEYWORDS:

• Ball end milling
• difficult-to-cut
• metals
• uva-bem
• cutting force
• tool wear
• surface integrity

Highlights of the manuscript

1. Ultrasonic vibration assisted ball end milling of difficult-to-cut metal.

2. Machinability analysis in terms of cutting force, tool wear and surface integrity.

3. Vibration of tool in longitudinal direction at ultrasonic frequency and low amplitude.

4. Analysis of the cutting tool performance and effect of vibration assistance.

Enhancement of machinability characteristics was found by the application of ultrasonic vibration assistance to the tool.

Acknowledgments

The authors are highly thankful to Mr. Saood Ali for his support during the research. Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Science, ICT, and Future Planning [Grant Number NRF-2020R1A2B5B02001755] supported this study.