Experimental studies were carried out on copper tube formabilities of Tube-end Spinning. The purpose of this forming method is to get high reduction ratio for tube nose forming without external heating. In this operation, the tubular stocks are softened with frictional heat generated at interface between the surface of tubular stock and the revolving conical die which has longitudinal grooves. Those grooves play a role as a heat relief area at die innerface. The results obtained are as follows.
(1) The grooves provided at innerface of die as heat-relief area affect greatly the formabilities, the tubular stocks are nose formed repeating radial deflection in the grooves and undergoing alternating stresses of compression and tension in the tube material.
(2) Formed portion is recrystallized with frictional heat, the longer the forming time, the greater the growth of recrystallized grains.
(3) Spinning power is controlled by die revolution, feeding of tubular stock, and heat relief area ratio, spinning power is decreased with increase of heat-relief area and of die revolution, and is increased with increase of the feeding of tubular stock.
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