Patent ID: 7670644

Claim:
A method for manufacturing a die for extrusion-forming a honeycomb structure, which comprises: forming a substrate layer, by a process including electroless plating, on a die base provided with ceramic puddle introducing holes and slits in communication with the ceramic puddle introducing holes; pickling surface of the formed substrate layer with dilute acid; and forming a surface layer on the substrate layer by chemical vapor deposition (CVD) so as to provide slits of a specified width, wherein the formation of the surface layer by chemical vapor deposition (CVD) is carried out while feeding a reaction gas consisting of WF 6 , C 6 H 6 and H 2 to a reaction chamber at an atmospheric temperature of 310 to 380° C. and at an atmospheric pressure of 1 to 35 Torr, the surface layer is made of tungsten carbide particles which are 5 μm or less in average particle diameter and contain W 3 C as a main ingredient, and the W/C molar ratio of the reaction gas is 0.6 to 3.