An Oscillatory Deep-Drawing Analogue
Consideration is given to the application of ultrasonic vibration ot the deep-drawing process. It is argued that from an understanding of the mechanics of cup-drawing, excitation of the die in a radial mode is likely to yield greatest benefit.
The desirability of quantifying both the surface and volume effects of ultrasonic excitation prompted the design of a simulative oscillatory test based on the Sach’s wedge-drawing test. Careful design of the tool configuration, using a wedge test-piece having bi-axial symmetry, permitted measurement of the frictional forces associated with both the blank-holder plate and die profile radius.
Experimental results obtained with commercially pure aluminium indicated that 13 kHz, die vibration at an amplitude of 5 × 105 in reduced the effective blank-holder friction force to zero. Reductions in punch load of up to 40 per cent were obtained with increased die amplitude and the limiting draw ratio, under these particular test conditions, was increased from 1·90 to 2·00. It was inferred from the results of oscillatory wedge tests that significant benefits could be obtained by the correct application of vibrations to the axisymmetric process of cup-drawing.
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