DIE FOR HIGH FREQUENCY HEATING

• Main Author: ARAI TAKASHI
• Format: Patent
• Language: English
• Published: 15.02.1991
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

PURPOSE:To obtain a die, which is excellent in high frequency induction heating characteristics and, at the same time, has excellent mirror smoothness and mechanical and thermal strengths by a method wherein an electroformed nickel layer and an electroformed copper layer are piled onto a ferrous metal base material and, after that, a chromium plated or titanium compound layer is piled on the surface of the copper layer after being machined. CONSTITUTION:After a nickel layer 51 having the thickness of 20mum and a copper layer 21 having the thickness of 100mum are deposited in the order named by electroforming on a base material 11, which is made of steel material of SKD 61 and subject to machining such as cutting grinding and the like. The resultant base material is annealed by being heated up to 250 deg.C. Next, the die consisting of said three layers is finish-turned and a hole for a mirror-finished lens core is bored at the center of the die. After that, a dummy core 61 is inserted in the hole. Mirror-finish turning for a Fresnel lens is applied to the copper layer 21 with a diamond bit and at the same time to the dummy core. Next, after the dummy core 61 is removed from the hole, a mirror-finished core 62 made of nickel emulsing steel is insertingly fitted to the hole. After that, chromium plating having the thickness of 1mum is applied to the whole die.