Warm Deep Drawing by Friction Heating Punch

Abstract

Warm processing was performed by frictional heat generation between different materials installed inside the punch. Forming with press machine is a technology for processing materials by applying heat and force, and is an important technology for industrial machines such as automobiles and electronic devices. For light metals such as aluminum alloys and magnesium alloys, it may be difficult to form depending on the type of alloy in cold deep drawing. As a method of improving formability, warm working is performed in which the metal die heated and deep drawing is performed. However, warm working requires many control devices such as heating and cooling for the mold. Using a prototype punch with a built-in friction heat generation jig, friction heat was generated by combining several types of steel materials. The changes in the exothermic temperature were mainly investigated in the combination of different materials. The test materials were carbon steel, tool steel, and stainless steel. The heat generation temperature generated by friction was measured by a thermocouple installed inside the heat generation jig. The friction surface of the jig after frictional heat generation was observed by a microscope. In frictional heating, the temperature of the processed area reached more than 350 °C in a few minutes. The proposed method was able to heat the punch. After frictional heating, the load of deep drawing of pure aluminum sheet decreased. It was found that there is a possibility of improving workability by warm deep drawing.