| 摘要 |
Articles are uniformly coated with alumina by using i.e. flame spraying as in Specification 745,257, a rod of 8-40 porosity and having a modulus of rupture greater than 2000 lbs./sq.in. The rod, if sintered, contains at least 95% alumina; if a vitrified bonded one, contains 50-96% alumina. Specified vitrified bond is derived from talc and Wellastonite (see Group V).ALSO:A sintered or vitrified bonded rod of 8-40% of open and interconnected pores and having a modulus of rupture greater than 2000 lbs/sq. in. contains, in the sintered rod at least 95% alumina-; in the vitrified rod 50 to 96% alumina. Ball clay wolastonite and talc can be added to the alumina, to which is then added a pore for uses, e.g. corn starch, organic resins, sawdust, coffee, or p dichlorobenzene, a temporary binder dextrine, and water. The mixture is extruded, dried and fired. Specification 745,257 is referred to. |
