| 摘要 |
PURPOSE:To obtain forming dies capable of forming an optical glass element having high image forming quality by a direct press forming method by forming a Pt-Re alloy film on a heat resistant base material having a satisfactory adhesive property to the alloy film and superior working accuracy. CONSTITUTION:A heat and thermal shock resistant material which undergoes easily precision working, e.g., tungsten carbide, cermet or zirconia is used as a base material. A binary Pt-Re alloy film reacting hardly with optical glass and having high hardness is formed on the base material. An alloy film consisting of Pt, Re and one or more among Ir, Os, Rh, Pd and Ru or one kind of oxide selected among titania, thoria and zirconia may be formed. When forming dies are made of the resulting material, this purpose can be attained because the alloy film does not react with optical glass contg. lead or alkali elements even at a high temp., the surface is not scratched, and plastic deformation is not caused during press forming.
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