The invention relates to an accurate
extrusion mould and method of a light
alloy stepped workpiece. The accurate
extrusion method of the light
alloy stepped workpiece is characterized by comprising the following steps of:
processing a convex crossed guide on a convex mould part and a crossed guide groove on a concave mould part, wherein the convex crossed guide is matched with the crossed guide groove; retaining the thickness of a step shape on a preformed planar blank; and filling
metal into a cavity part, which is arranged on the side wall of the cuspidal edge and
closed angle stepped surface of a convex mould or a concave mould and is provided with a groove used for
metal flow in a vertical direction, by adopting a flow direction
sequence control method so as to achieve the purpose of the formation of a cuspidal edge and
closed angle step of the workpiece; and placing isopyknic blanks into the concave mould by adopting primary heating: a. prepressing by using a prepressing
mandril, and b. finally forming by using the convex mould. The accurate
extrusion module and method provided by the invention have the advantages of high utility ratio of materials, short manufacturing process, high accuracy and efficiency, low cost, and the like.