A surface layer including a base material made of a conductor and dispersed particles dispersed in the base material is formed on a surface of a fixed contact, and the dispersed particles each include a base particle that is metal oxide and a coating layer formed on an outer surface of the base particle.

A method for producing an electrical contact includes a step of preparing an electrical contact material including a layer that contains a carbon material on a base material that contains a metallic material having resistivity of 1.5910.sup.8 m to 9.0010.sup.7 m; and a step of processing the electrical contact material obtained to produce an electrical contact, wherein the carbon material is a graphene monolayer or a graphene laminate in which a plurality of the graphene monolayers is laminated, the step of preparing an electrical contact material includes a step of laminating a carbon material layer in which the layer that contains the carbon material is laminated on the base material by microwave surface-wave plasma CVD method or thermal CVD method, and the step of laminating a carbon material layer includes supplying a mixed gas including a source gas that contains carbon and hydrogen gas.

A modular auxiliary switch includes a housing including a first housing part and a separate second housing part secured to the first housing part. A printed circuit board is housed in one of the first and second housing parts, and has a first side facing the first housing part and a second opposite side facing the second housing part. An actuator mechanism is housed in the first housing part and is coupled to the printed circuit board. A separate first electrical contactor is selectively mounted to the printed circuit board so that a first electrical contact surface of the first electrical contactor overlaps and is in direct contact with one of the first side and the second side to define a first electrical contact pad on the printed circuit board.

An arc-ablation resistant tungsten alloy switch contact and preparation method is disclosed. A contact member has a three-layer structure, wherein a first layer is a hydrophobic rubber layer, a second layer is a sheet metal layer, and a third layer is a tungsten alloy chemical deposition layer. A plating bath adopted in the chemical deposition contains 25-125 g/L soluble tungsten compound, 0-60 g/L soluble compound of a transition metal like ferrum, nickel, cobalt, copper or manganese, and 0-30 g/L soluble compound of tin, stibium, lead or bismuth. When a layered complex of the hydrophobic rubber layer and the sheet metal layer is chemically plated by the plating bath, a tungsten alloy plated layer is selectively deposited on a metal surface, and chemical deposition of the tungsten alloy does not occur on a surface of the hydrophobic rubber fundamentally.

There is provided a silver-plated product which has good thermal resistance, bendability and wear resistance. In a silver-plated product wherein a surface layer of silver having a thickness of 10 m or less is formed on a base material of copper or a copper alloy, the full-width at half maximum of a rocking curve on a preferred orientation plane (preferably {200} or {111} plane) of the surface layer is caused to be 2 to 8, preferably 3 to 7, to improve the out-of-plane orientation of the surface layer to improve the thermal resistance, bendability and wear resistance of the silver-plated product.

This invention discloses a preparation method for precious metal switching contact components by means of plating masking, plating and etching processes. The plating masking process is performed by using a plating mask ink with or without a photo exposure machine. Plating of precious metals is performed by electroless plating or electro plating methods. Etching is carried out with etching solutions containing weak organic acids, weak inorganic acids or acidic buffering agents. Improvement of the etched surface gloss and prevention of the side etching are realized with the sulfur-contained compounds. The dust- and oil stain-resistances of the switch contacts are improved by increasing the etching depth. The switch contacts made by this invention are featured with the advantages of good reliability, good resistance to dust and oil stain, short contact bounce time, long service life, low cost of raw materials and so on.

A surface layer including a base material made of a conductor and dispersed particles dispersed in the base material is formed on a surface of a fixed contact, and the dispersed particles each include a base particle that is metal oxide and a coating layer formed on an outer surface of the base particle.

An electrical contact material may include a first contact that contacts a negative electrode; a third contact that contacts a positive electrode; and a second contact that is provided between the first contact and the third contact, wherein different plating materials are respectively attached to the first contact, the second contact, and the third contact.

An arc-ablation resistant switch contact and a preparation method thereof is disclosed. The switch contact is a complex having a plurality of layers of layered structure, wherein a first layer is a hydrophobic rubber layer, a second layer is an adhesive layer, a third layer is a sheet metal layer, a fourth layer is an adhesive layer, and a fifth layer is a metal plated layer; wherein, the fifth layer of metal plated layer is formed by dipping a complex of the first layer, the second layer, the third layer and the fourth layer in a chemical plating bath containing refractory metal elements, and depositing on surfaces of the second layer, the third layer and the fourth layer in the complex by a chemical deposition method.

An arc-ablation resistant tungsten alloy switch contact and preparation method is disclosed. A contact member has a three-layer structure, wherein a first layer is a hydrophobic rubber layer, a second layer is a sheet metal layer, and a third layer is a tungsten alloy chemical deposition layer. A plating bath adopted in the chemical deposition contains 25-125 g/L soluble tungsten compound, 0-60 g/L soluble compound of a transition metal like ferrum, nickel, cobalt, copper or manganese, and 0-30 g/L soluble compound of tin, stibium, lead or bismuth. When a layered complex of the hydrophobic rubber layer and the sheet metal layer is chemically plated by the plating bath, a tungsten alloy plated layer is selectively deposited on a metal surface, and chemical deposition of the tungsten alloy does not occur on a surface of the hydrophobic rubber fundamentally.