Die for ironing working and die module

Abstract

A die ( 30 ) for ironing working, the die ( 30 ) having a carbon film 50 covering at least a working surface ( 41 ) thereof, the carbon film ( 50 ) exhibiting such a Raman spectrum that an intensity ratio represented by the following formula (1): I D /I G   (1) wherein I D is a maximum peak intensity at 1333±10 cm −1 in the Raman spectrum of the surface of the carbon film, and I G is a maximum peak intensity at 1500±100 cm −1 in the Raman spectrum of the surface of the carbon film, is not less than 1.0, and the surface of the carbon film 50 being a smooth surface having an arithmetic mean roughness R of not more than 0.1 μm.

1 . A die for ironing working, said die having a carbon film that is so formed as to cover at least a working surface thereof, said carbon film exhibiting such a Raman spectrum that an intensity ratio represented by the following formula,
     I   D   /I   G      wherein I D  is a maximum peak intensity at 1333±10 cm −1      in the Raman spectrum of the surface of said carbon film,   and I G  is a maximum peak intensity at 1500±100 cm −1      in the Raman spectrum of the surface of said carbon film,   
       is not less than 1.0, and a surface of said carbon film being a smooth surface having an arithmetic mean roughness R of not more than 0.1 μm. 
     
     
         2 . The die for ironing working according to  claim 1 , wherein said carbon film is a diamond film having said intensity ratio of not less than 1.2. 
     
     
         3 . The die for ironing working according to  claim 1 , wherein the surface of said carbon film has the arithmetic mean roughness Ra of not more than 0.05 μm. 
     
     
         4 . A die module comprising the die for ironing working of  claim 1 , and a holder which is so provided as to hold a non-working surface of said die from an upstream side in a working direction and from a downstream side in the working direction, said holder having therein a temperature-control fluid passage for so flowing a temperature-control fluid as to come in contact with the non-working surface of said die. 
     
     
         5 . The die module according to  claim 4 , wherein, as viewed on a side section along the direction of working, said temperature-control fluid passage is so formed that the temperature-control fluid comes in contact with both a side surface which is the non-working surface of said die on the upstream side in the working direction and a side surface which is the non-working surface of said die on the downstream side in the working direction. 
     
     
         6 . The die module according to  claim 4 , wherein said carbon film is continuously formed up to the non-working surface that comes in contact with the fluid that flows in said temperature-control fluid passage.