Composite metal molding and method for manufacturing thereof
A compression molding which is high in both dimensional accuracy and mechanical strength is difficult to manufacture by a powder molding process. Especially, a molding including a soft magnetic material with high soft magnetic properties is difficult to manufacture. A composite metal molding according to the present invention includes metal particles and the carbide of a resin intervening among the particles. It is manufactured by coating metal particles with a resin, molding the prepared molding material under pressure into a predetermined shape, and heating the prepared pressurized preform to calcine the resin and weld mutually the particles. The carbide of the resin has a weight ratio of 0.001 to 2% to the metal particles when the particles have their proportion expressed as 100. The particles have a weld ratio of 10 to 80%. The particles preferably contain a soft magnetic material and the resin is preferably a furan resin.
1. A method for manufacturing a composite metal molding, comprising the steps of:
coating metal particles containing a soft magnetic material with a resin to prepare a molding material;
molding the molding material under pressure into a predetermined shape to make a pressurized preform; and
heating the pressurized preform to calcine the resin and weld mutually the metal particles to make a composite metal molding including the metal particles and the carbide of the resin intervening among the metal particles;
wherein the step of heating the pressurized perform includes annealing the soft magnetic material to remove its internal strain.
2. A method as claimed in claim 1 , wherein the resin is a thermosetting resin and further comprising the step of curing the resin by heating the pressurized preform.
3. A method as claimed in claim 2 , wherein the resin is a furan resin.
4. A method as claimed in claim 3 , wherein the step of heating the pressurized preform includes heating the pressurized preform at a temperature in the range of 500° C. to 1,000° C.