| 摘要 |
1488875 Moulding refractories UNITED KINGDOM ATOMIC ENERGY AUTHORITY 26 Feb 1975 [1 March 1974] 9456/74 Addition to 1371894 Heading B5A [Also in Division C7] A shaped refractory article is made by compression moulding at elevated temperature a mixture of refractory powder and a thermosetting or thermoplastic binder in a mould which includes a rigid pattern preformed from a resin, and subsequently heating the moulded article to remove the binder and firing it to form the refractory article. Silicon powder with polyvinyl butyral binder is moulded at 100‹ C. in a metal die which includes a filled epoxy pattern which has been cast in a rubber mould. The pattern is mostly removed by grinding, the remainder disappearing on firing. Alternatively the rubber mould may be coated with a bismuth tin alloy which transfers to the pattern so that on heating the moulded article the metal melts and releases the pattern. The silicon is nitrided during firing to form a silicon nitride fluidio element. Other refractories include glasses, metals, carbides, alumina, zirconia, and technical ceramics. The rigid pattern may be of phenolic, polyester, polyamide or silicone resin. |
