| 摘要 |
1,125,452. Glass and ceramic mixtures; ceramics. AMPHENOL CORP. 17 Sept., 1965 [16 Oct., 1964], No. 39848/65. Headings C1J and C1M. Moulded ceramic articles are made by mixing a major proportion of a ceramic material which either cannot be vitrified or has a high vitrification temperature with a minor proportion of a second ceramic material which has a lower vitrification temperature than the first material, and with a silicone resin and a plasticizer, shaping the mix, at least partially thermosetting the resin, and firing the product at a temperature intermediate the vitrification temperatures. The major ceramic material is preferably alumina, but may be magnesia, zirconia, titania, thoria, beryllia, silica, the carbides of Si, Ti, Zr, Cr, W, Mo or graphite or amorphous carbon. The minor ceramic material is preferably wollastonite and/or glass frit, but may be mullite, forsterite, feldspar, spodumene, steatite, silica and quartz. Any silicone resin will serve, with a catalyst (examples given) for speeding the setting. The preferred plasticizer is beeswax, but others (stearates, methacrylates) are mentioned. The operable proportions for a preferred mix are (parts by weight): alumina 90 to 50, wollastonite 5 to 40, glass frit 2 to 25, silicone resin 8 to 25, and beeswax 0À4 to 5À0. A specific example of the above mix is described (including the composition of the glass frit), the mix being moulded for 5 to 10 minutes at 320‹ F. and fired for 1 hour at 2000‹ F. The article comprises a glassy matrix containing crystalline particles of a ceramic material and particles of silica in the form of the decomposition product of silicone resin. |
