Patent ID: 9248526
Filing Date: 2016-02-02
CPC Classification: B22F,B23K

Claim Text:
1. A method for manufacturing a welding material comprising in the order below: a compound preparing step in which a compound is prepared by mixing alloy powder containing a first alloy powder having a first average particle size and a second alloy powder having a second average particle size smaller than the first average particle size, a water soluble binder and water; an extruding step in which an extruded formed body is prepared by extruding the compound prepared in the compound preparing step from a forming nozzle using an extrusion machine; a degreasing step in which the binder is removed from the extruded formed body prepared in the extruding step by heating the extruded formed body to a predetermined temperature of 400° C. or above under an inert gas atmosphere, a reducing gas atmosphere or a reduced pressure atmosphere; a C—O reaction step in which oxygen present on a surface of and in the inside of the alloy powder and carbon derived from the binder are removed by causing a reaction between oxygen and carbon by heating the extruded formed body from which the binder is removed in the degreasing step to a predetermined temperature which falls within a range of 950° C. to 1150° C. under a vacuum atmosphere; a sintering step in which the welding material is formed from the extruded formed body, the extruded formed body from which oxygen present on the surface of and in the inside of the alloy powder and carbon derived from the binder are removed in the C—O reaction step is heated to a predetermined temperature which fails within a range of 1200° C. to 1350° C. under an inert gas atmosphere, a reducing gas atmosphere or a mixed gas atmosphere made of an inert pas and a reducing gas thus forming the welding material; and a drying step carried out after the extruding step and before the degreasing step in which moisture is removed from the extruded formed body, wherein: in the compound preparing step, a ratio of water to the alloy powder falls within a range of 1.0 weight % to 2.1 weight %, and the extruding step is carried out using a compound with a viscosity in a range of 1.8 P (poise) to 2.5 P (poise), as measured by a flow characteristic tester and the first alloy powder is a Co-based powder.