Ultrasonic enhancement of grain growth in copper

Abstract

The influence of 20 kc ultrasonic energy on grain growth kinetics in O.F.H.C. copper was investigated. Half-wavelength specimens resulted in resonant standing waves with a maximum acoustic stress amplitude of 2·4 × 10⁸ dynes/cm². Acoustic energy caused an acceleration in grain growth rate. The grain growth exponent, n, in the equation D=βtⁿ was increased from 0·11 to 0·31, where D is the grain diameter at growth time t and β is a constant.