RETRACTED: Material-removal-rate analysis in the ultrasonic machining of engineering ceramics

This article has been retracted at the request of the Editor-in-Chief. Reason: It has been discovered that this article has heavily duplicated information verbatim from the original article, Journal of Materials Processing Technology, 71 (1997) 195–201. The Publisher, on behalf of the Editor-in-Chief, would like to apologize to the original authors for this error and therefore requested this retraction.