METHOD FOR MAKING BUILDUP PRODUCTS WITH LENGTHWISE LAMINARITY Russian patent published in 1998 - IPC

FIELD: plastic metal working, namely, manufacture of buildup- thickness hollow blanks for hot extrusion of tubes with clad working surface. SUBSTANCE: method comprises steps of placing one hollow blank inside another, inner blank is made of less strength material than outer one; assembling blanks and fixing them one relative to another, heating buildup blank, arranging it onto needle for subsequently extruding through cone die due to placing blank in container; applying axial compression effort to end of buildup blank. Novelty is formation of at least three lengthwise protrusions on inner surface of blank of less-strength material at process of fixing blanks. Protrusions have length values less than that of buildup blank and they are uniformly distributed along perimeter of inner blank in such a way that their apexes are laid on circle with diameter less than that of needle. EFFECT: enhanced efficiency. 1 cl, 4 dwg