Contact material, composite sintered contact component and method of producing same

A composite sintered contact component, wherein a sintered contact material, containing 10% by volume or more a Fe base alloy phase having a composition range which causes an order-disorder transition, is integrated with a sheet-like, cylindrical or substantially cylindrical backing made from an iron base material.

A method for producing a composite sintered contact component by integrating a sintered contact material with a cylindrical or substantially cylindrical backing, the sintered contact material having 10% by volume or more a Fe base alloy phase which causes an order-disorder transition, the backing being made from an iron base material,

• wherein the sintered contact material contains metallic Al which causes expansion of the sintered contact material and 10 to 70 wt % Cu which is used as an element for generating a liquid phase within a high temperature zone to ensure sinter strength and sinter bondability,
• wherein a compact made from the sintered contact material is a cylindrical component having an outer diameter equal to or slightly smaller than the inner diameter of the backing, and
• wherein when the cylindrical component is heated to 900° C. or more, being inserted into the backing, (a) the sintered contact material is expanded by heating at a temperature of 800° C. or more for a specified period of time and bonded to the backing by utilizing a Cu base alloy liquid phase which has been generated at the expansion temperature, and (b) the sintered contact material is further heated at a temperature of 900° C. or more thereby generating more Cu base alloy liquid phase to compact the sintered contact material.

A method for producing a composite sintered contact component by integrating a sintered contact material with a sheet-like backing made from an iron base material, the sintered contact material containing 10% by volume or more a Fe base alloy phase which causes an order-disorder transition, wherein the sintered contact material contains the Fe base alloy phase which causes an order-disorder transition and at least 10 to 70 wt % Cu and 3 to 10 wt % Sn which serve as elements for generating a liquid phase within a high temperature zone to ensure sinter strength and sinter-bondability, and

• wherein a powder blend for producing the sintered contact material is dispersed onto the surface of the backing, and after sintering in a neutral, reduced or vacuum atmosphere, a sintered layer formed on the backing is compressed with a rolling mill or a press and then subjected to a re-sintering process at least once in the neutral, reduced or vacuum atmosphere, whereby sinter-bonding is carried out.