Recent Experiences with the Variables of the Ultrasonic Machining Process

Abstract

Experimental results are presented which demonstrate the dependence of the ultrasonic machining rate in Ketos tool steel on variables associated with the ultrasonic machining process. These variables include the peak to peak amplitude and the frequency of vibration of the tool tip; the geometric shape of the tool tip; the pressure which is maintained between the tool tip and the work piece; the diameter of the abrasive particles and the ratio of the weight of the abrasive to the weight of the water vehicle used in compounding the slurry. An analysis of the experimental evidence makes it apparent that four constants are of fundamental importance in the ultrasonic machining process. One constant is a number representing the critical fractional part of an abrasive particle which is crowded into a cubic volume having sides equal to the abrasive particle diameter; another constant is the normal distance outward from the perimeter of the tool tip over which abrasive is effectively sucked underneath the tool tip; a third constant is the maximum pressure which a single abrasive particle can withstand; and the fourth constant is the ability of the work piece to translate a unit of pressure delivered by a single abrasive particle into a rate of machining. A phenomenological expression describing the experimental evidence is given in terms of the aforementioned variables and constants. [Work supported in part by the U. S. Air Force.]