A method of preparing silver-based oxide electrical contact materials with fiber-like arrangement, includes the following steps of: (1) uniformly mixing the silver-metal alloy powders and graphite powders and then ball-milling; (2) internally oxidizing the ball-milled powders; (3) sieving; (4) placing the sieved powders and the matrix powders into the powder mixer for mixing; (5) cold-isostatically pressing; (6) sintering; (7) hot-pressing; and (8) hot-extruding, thereby obtaining the silver-based oxide electrical contact material with fiber-like arrangement. The method of the present invention can obtain the silver-based oxide electrical contact material having neat fiber-like arrangement with no specific requirement on processing deformation, plasticity and ductility of the reinforcing phase. The production process in this method is simple and is easy to operate. Besides, there is no particular requirement on the equipment. The method greatly improves the performance of contact materials in aspects of resistance to welding and arc erosion, conductivity, and processing performance.

A circuit breaker including at least two contact tip that comprise an electrical contact material comprising silver (Ag) and tungsten (W). The contact tip further comprises a graphene material (Gr) additively mixed in Ag as being denoted as AgGr0.3% or AgGr0.5% which is mixed with tungsten (W) to form (AgGr0.3)W50 or (AgGr0.5)W50 called a silver-graphene tungsten composite material.

A circuit breaker including at least two contact tip that comprise an electrical contact material comprising silver (Ag) and tungsten (W). The contact tip further comprises a graphene material (Gr) additively mixed in Ag as being denoted as AgGr0.3% or AgGr0.5% which is mixed with tungsten (W) to form (AgGr0.3)W50 or (AgGr0.5)W50 called a silver-graphene tungsten composite material.

A material and method for manufacturing an Ag-based electrical contact material includes synthesizing an intermetallic compound of Me.sub.xSn.sub.y type; ball milling the intermetallic compound; mixing the so obtained intermetallic compound powder with silver powder; packing the mixed powders into a green body; and forming a MeO—SnO.sub.2 cluster structure by internally oxidizing the intermetallic compound Me.sub.xSn.sub.y while sintering the green body.

A method for producing a contact material on the basis of silver-tin oxide or silver-zinc oxide is disclosed. Tin oxide particles and/or zinc oxide particles are mixed with a powder of a metal different from silver. The mixture is heated beyond the melting point of the metal powder such that the tin oxide particles and/or zinc oxide particles are wetted with liquid metal. The mixture is exposed to an atmosphere containing oxygen and the metal is thereby oxidized. Thereafter, the mixture product formed by the oxidation step is embedded as a powder into a silver matrix. The product further relates to a corresponding contact material.

A material and method for manufacturing an Ag-based electrical contact material includes synthesizing an intermetallic compound of Me.sub.xSn.sub.y type; ball milling the intermetallic compound; mixing the so obtained intermetallic compound powder with silver powder; packing the mixed powders into a green body; and forming a MeO-SnO.sub.2 cluster structure by internally oxidizing the intermetallic compound Me.sub.xSn.sub.y while sintering the green body.

A method for producing a contact material on the basis of silver-tin oxide or silver-zinc oxide is disclosed. Tin oxide particles and/or zinc oxide particles are mixed with a powder of a metal different from silver. The mixture is heated beyond the melting point of the metal powder such that the tin oxide particles and/or zinc oxide particles are wetted with liquid metal. The mixture is exposed to an atmosphere containing oxygen and the metal is thereby oxidized. Thereafter, the mixture product formed by the oxidation step is embedded as a powder into a silver matrix. The product further relates to a corresponding contact material.

A process for producing a cadmium free electrical contact material having at least one metal and magnesium stannate Mg.sub.2SnO.sub.4. The process includes mixing pulverulent magnesium stannate Mg.sub.2SnO.sub.4 or a mamesium stannate precursor compound with at least one metal powder and optionally further oxides, pressing the mixture in order to obtain a compact and sintering the compact to obtain a sintered body.

An electrical contact tip for switching applications. The contact tip includes a body having a first layer and a second layer. The first layer arranged on the second layer and adapted to come in contact with a corresponding contact tip during switching operations. The first and second layers consist of Ag-composites of one or more elements, compounds or alloys, where the hardness of the first layer is lower than the hardness of the second layer.

An electrical contact tip for switching applications. The contact tip includes a body having a first layer and a second layer. The first layer arranged on the second layer and adapted to come in contact with a corresponding contact tip during switching operations. The first and second layers consist of Ag-composites of one or more elements, compounds or alloys, where the hardness of the first layer is lower than the hardness of the second layer.