Abstract: A preform for use in a metal matrix composite, particularly for a magnesium metal composite. In the preform the reinforcing material typically is silicon carbide, boron nitride, titanium nitride, carbon or graphite. The binder used in the preform is sintered magnesium fluoride, which avoids the known problems which result from the high reactivity of molten magnesium metal with other binders, such as silica and alumina, which results in the formation of magnesium oxide in the reinforced composite. The presence of magnesium oxide crystals in the metal matrix adversely affects the properties of the composite. The preform generally has a void volume of from about 50% to about 95%.

Abstract: A preform for use in a metal matrix composite, particularly for a magnesium metal composite. In the preform the reinforcing material typically is silicon carbide, boron nitride, titanium nitride, carbon or graphite. The binder used in the preform is sintered magnesium fluoride, which avoids the known problems which result from the high reactivity of molten magnesium metal with other binders, such as silica and alumina, which results in the formation of magnesium oxide in the reinforced composite. The presence of magnesium oxide crystals in the metal matrix adversely affects the properties of the composite. The preform generally has a void volume of from about 50% to about 95%.

Abstract: A preform for use in a metal matrix composite, particularly for a magnesium metal composite, and a metal matrix composite, typically made by squeeze casting, using the preform. In the preform the reinforcing material typically is silicon carbide, boron nitride, carbon or graphite. The binder used in the preform is magnesium fluoride, which avoids the known problems which result from the high reactivity of magnesium metal with other binders, such as silica and alumina, which results in the formation of magnesium oxide in the reinforced composite. The presence of magnesium oxide crystals in the metal matrix adversely affects the properties of the composite.

Abstract: A preform for use in a metal matrix composite, particularly for a magnesium metal composite, and a metal matrix composite, typically made by squeeze casting, using the preform. In the preform the reinforcing material typically is silicon carbide, boron nitride, carbon or graphite. The binder used in the preform is magnesium fluoride, which avoids the known problems which result from the high reactivity of magnesium metal with other binders, such as silica and alumina, which results in the formation of magnesium oxide in the reinforced composite. The presence of magnesium oxide crystals in the metal matrix adversely affects the properties of the composite.

Abstract: A process for preparing a preform for use in a metal matrix composite, particularly for a magnesium metal composite, and a metal matrix composite, typically made by squeeze casting, using the preform. In the preform the reinforcing material typically is silicon carbide, boron nitride, carbon or graphite. The binder used in the preform is magnesium fluoride, which avoids the known problems which result from the high reactivity of magnesium metal with other binders, such as silica and alumina, which results in the formation of magnesium oxide in the reinforced composite. The presence of magnesium oxide crystals in the metal matrix adversely affects the properties of the composite.

Abstract: A reliable gaseous hydrogen detection and measuring device which is simple, easy to use, does not require any reference gas supply, and which can be of reasonably rugged construction. The device utilizes a disc comprising a solid state ceramic hydronium conductor of the general formula Na(H.sub.3 O)Zr.sub.2 Si.sub.x P.sub.(3-x) O.sub.12 together with a silver based electrode system on one side, and a catalytic noble metal electrode, such as platinum, on the other. By measurement of the output voltage across the electrodes, both the presence, and the amount, of hydrogen in a gaseous system can be determined.

Abstract: Hydronium bonded polycrystalline shaped articles may be produced by the simple expedient of selecting a hydronium containing powder prepared by one of a plurality of prior art methods and then intermingling the hydronium powder with ortho-phosphoric acid to obtain a viscous mixture (resembling the consistency of toothpaste). The mixture is then formed into a predetermined shape, for example a disc or tube, and the shaped polycrystalline ceramic is allowed to cure. Curing may take place at an elevated temperature below 100.degree. C. for approximately 3 hours either as a step subsequent to forming, or as part of the forming step in 30 minutes at 120.degree. C. The result is bonded hydrogen conducting - hydronium, H.sub.3 O+, solid rigid structure with a smooth finish copying the mold from which it was shaped.

Abstract: An improved acheson furnace structure is shown having insulated gate means for increasing the volume of coarsely crystalline silicon carbide produced in each cycle of the furnace together with a reduction in the volume of fire sand required to be recycled whereby to improve the efficiency of the furnace.

Abstract: Silicon oxynitride, Si.sub.2 ON.sub.2 is made, without the need for a catalyst such as CaO, by heating a mixture of powdered silica and silicon in an inert atmosphere at a temperature below the melting point of silicon, and subsequently nitriding the mixture to form silicon oxynitride with minimal silicon nitride contamination.

Abstract: A reliable gaseous hydrogen detection and measuring device which is simple, easy to use, does not require any reference gas supply, and which can be of reasonably rugged construction. The device utilizes a disc comprising a solid state ceramic hydronium conductor of the general formula Na(H3O)Zr2SixP(3−x)O12 Na(H3O)xZr2SixP(3−x)O12 together with a silver based electrode system on one side, and a catalytic noble metal electrode, such as platinum, on the other. By measurement of the output voltage across the electrodes, both the presence, and the amount, of hydrogen in a gaseous system can be determined.