超音波付加引抜加工の引抜力について

Abstract

When an ultrasonic is applied during wire drawing, the decrease of drawing stress is observed. From a study of comparison of the draw-bench apparatus with the bull-block apparatus, it has been comfirmed that the decrease of drawing stress is steadily dropped by the latter apparatus. Then, using the bull-block apparatus, the relation ships of the drawing stress with the percentage of reduction, amplitude of applied ultrasonic and drawing speed have been investigated in details. The following results are obtained.(1) When the drawing speed is increased, no effect of ultrasonic on the drawing stress is observed. The relation between the limit of drawing speed vt,l and maximum wave velocity vf,max is expressed as vf,max×(1⁄π)=vt,l.(2) The effect of amplitude on the decrease of the drawing stress is examined with SUS 24 and SUS 27, respectively. In SUS 24, the decreasing ratio of the drawing stress varies at the amplitude of 4 micron, but in SUS 27, it varies linearly with the amplitude.(3) When the ultrasonic drawing is superimposed upon the usual one, the wire indicates the effect of ultrasonic cleaning which improves the wettability between the wire and the lubricant, and the drawing stress decreases independently of the amplitude.(4) The decrease of the drawing stress by ultrasonic does not depend on the reduction of cold working.(5) Up to the reduction of 89% in continuous drawing, the drawing stress and the relative drawing stress show different behaviors at 66% reduction.