CRUCIBLE MADE OF TUNGSTEN MOLYBDENUM ALLOY, METHOD FOR PRODUCING IT AND METHOD FOR PRODUCING SAPPHIRE SINGLE CRYSTAL

摘要

PPROBLEM TO BE SOLVED: To provide a crucible made of a tungsten molybdenum alloy having high strength, particularly high strength in the corner part connecting the bottom part and the side wall parts, and a method for producing it. PSOLUTION: The crucible 1 made of a bottomed cylindrical tungsten molybdenum alloy has an upper open part in which a bottom part 2 made of a tungsten molybdenum alloy comprising 1 to 60 mass% tungsten, and the balance molybdenum, and side wall parts 3 are connected via a corner part 4, the average crystal grain size is 100 m, and, regarding the method for producing the crucible 1, the crucible is produced by a powder sintering process including: a mixing step of mixing tungsten powder with molybdenum powder; a molding step of molding the mixture into a crucible shape by CIP (Cold Isostatic Pressing) molding under the pressure of 1ton/cmSP2/SP; a first sintering step of performing sintering at 1,400C in a hydrogen atmosphere; and a second sintering step of performing sintering at 2,000C in a reducing atmosphere or in an inert atmosphere. PCOPYRIGHT: (C)2011,JPO&INPIT