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

FIELD: plastic metal working, possibly production of tubes with clad working surface by hot extrusion. SUBSTANCE: product is assembled of two arranged one inside another hollow blanks. Inner blank is in the form of sleeve with locally thickened wall. Outer blank is placed onto said sleeve in such a way that it is supported by said thickened portion of sleeve. Material of said sleeve is axially compressed in limits of small cross section of said sleeve and then said thickened portion is removed. At axial compression shoulder is formed on one end of blank. Said shoulder is arranged at side of die of extrusion press. EFFECT: high quality welding of materials. 2 cl, 6 dwg