SHAPE EXTRUSION METHOD Russian patent published in 2004 - IPC

FIELD: plastic working of materials, possibly manufacture of shapes, mainly rods by hot extrusion of hard-to-form alloys. SUBSTANCE: method of extruding shapes comprises steps of feeding to container cylindrical blank heated until extrusion temperature; placing between blank and pressure pad technological washer with inner cavity heated until predetermined temperature; pressing blank for forming protrusion on its rear end and extruding heated metal through die hole; heating technological washer until temperature no more than that of blank heating and no less than temperature of pressing protrusion. Yield limit of material of technological washer at predetermined heating temperature exceeds at least by 1.5 times that of blank material at extrusion temperature. Shape is extruded at elongation providing pressing of material of technological washer through die hole by length value no less than length of sizing portion of die. Cavity of technological washer has spherical surface; its volume is determined according to given expression V = 1/3πh²(3R-h), where height h of blank protrusion consists (0.15 - 0.25)Dbl; R - radius of spherical surface of blank protrusion consists (0.45 - 0.55)Dbl. EFFECT: pressing of the whole volume of material to article, lowered quantity of end scrap of shape, normalized properties of material along the whole length of extruded article. 2 cl, 3 dwg, 1 ex