| 摘要 |
PURPOSE:To improve the hardness and thermal impact resistance and to prolong the service life of a die by forming the nib of the die for wire drawing by Si-Al-O-N compound sintered compact and by limiting as well the size of each nib part. CONSTITUTION:The length of the back relief part 1a of a nib 1 is taken at 20-50% of the nib thickness t1 in the die for wire drawing using the nib 1 composed of the Si-Al-O-N compound sintered compact having excellent thermal impact resistance and high temp. intensity. The ratio of the diameter D1 of the nib to the thickness t1 of the nib is taken 1.20-2.5. The angle between the contact face of the outer periphery of the nib 1 and the inner periphery of the die case 2 and the center axis of the die is taken at 0.5-3 deg.. Further the fitting of the nib 1 and die case 2 is performed by pressing in and the ratio of the pressing in allowance is taken at 0.1-3%. Said die for wire drawing has lowaffinity with the metal and obtains good finishing surface, also a seizure is difficult to cause and it resists enough for the drawing under high temp. |
