Provided is a method which includes a first layer formation step of forming a first layer by using a first composition that contains a constituent material powder, a first powder, and a binder of a three-dimensional shaped article; a second layer formation step of forming a second layer by using a second composition that contains a second powder and a binder; a degreasing step of a stack containing the first layer and the second layer; and a sintering step of the stack, a decomposition point of the first powder is higher than decomposition points of the binder of the first layer and the binder of the second layer, a decomposition point of the second powder is higher than the decomposition point of the first powder, and a sintering temperature of the constituent material powder is higher than the decomposition point of the second powder.

Provided is a method which includes a first layer formation step of forming a first layer by using a first composition that contains a constituent material powder, a first powder, and a binder of a three-dimensional shaped article; a second layer formation step of forming a second layer by using a second composition that contains a second powder and a binder; a degreasing step of a stack containing the first layer and the second layer; and a sintering step of the stack, a decomposition point of the first powder is higher than decomposition points of the binder of the first layer and the binder of the second layer, a decomposition point of the second powder is higher than the decomposition point of the first powder, and a sintering temperature of the constituent material powder is higher than the decomposition point of the second powder.

An example of a composition includes a host metal present in an amount ranging from about 95.00 weight percent to about 99.99 weight percent, based on a total weight of the composition. A flow additive is present in an amount ranging from about 0.01 weight percent to about 5.00 weight percent, based on the total weight of the composition. The flow additive consists of a metal containing compound that is reducible to an elemental metal in a reducing environment at a reducing temperature less than or equal to a sintering temperature of the host metal. The elemental metal is capable of being incorporated into a bulk metal phase of the host metal in a final metal object. The composition is spreadable, having a Hausner Ratio less than 1.25.

An example of a composition includes a host metal present in an amount ranging from about 95.00 weight percent to about 99.99 weight percent, based on a total weight of the composition. A flow additive is present in an amount ranging from about 0.01 weight percent to about 5.00 weight percent, based on the total weight of the composition. The flow additive consists of a metal containing compound that is reducible to an elemental metal in a reducing environment at a reducing temperature less than or equal to a sintering temperature of the host metal. The elemental metal is capable of being incorporated into a bulk metal phase of the host metal in a final metal object. The composition is spreadable, having a Hausner Ratio less than 1.25.

A method for producing a metal shaped article having a porous structure includes a mold formation step of forming a mold having a plurality of columnar structures extending from a substrate by performing a resin material supply step of supplying a liquid containing a resin material to a plurality of places of the substrate at intervals in two directions crossing each other, and a curing step of curing the liquid, a sintering target material supply step of supplying a sintering target material to the mold, a removal step of removing the substrate, a degreasing step of degreasing the columnar structures, and a sintering step of sintering the sintering target material.

A method for producing a metal shaped article having a porous structure includes a mold formation step of forming a mold having a plurality of columnar structures extending from a substrate by performing a resin material supply step of supplying a liquid containing a resin material to a plurality of places of the substrate at intervals in two directions crossing each other, and a curing step of curing the liquid, a sintering target material supply step of supplying a sintering target material to the mold, a removal step of removing the substrate, a degreasing step of degreasing the columnar structures, and a sintering step of sintering the sintering target material.

Additive manufacturing techniques are used to achieve customized preforms for repair or manufacture of turbomachinery. A method of modifying a section of a product includes forming, a preform set to fit the section. A base material is selected with properties desired for the modification of the section. A binder is selected that vaporizes at a temperature below a melting point of the base material. The preform set is built by the selective application of the binder to the base material to achieve design dimensions of the section when the preform is joined to the section. The section is prepared for effecting the extent of modification and the preform is positioned on the section. The section and the preform are heated to substantially eliminate the binder from the preform and then thermally processed to harden the preform and to bond the preform to the section.

Additive manufacturing techniques are used to achieve customized preforms for repair or manufacture of turbomachinery. A method of modifying a section of a product includes forming, a preform set to fit the section. A base material is selected with properties desired for the modification of the section. A binder is selected that vaporizes at a temperature below a melting point of the base material. The preform set is built by the selective application of the binder to the base material to achieve design dimensions of the section when the preform is joined to the section. The section is prepared for effecting the extent of modification and the preform is positioned on the section. The section and the preform are heated to substantially eliminate the binder from the preform and then thermally processed to harden the preform and to bond the preform to the section.

A method of making a metal-polymer composite includes dealloying metallic powder to yield porous metal particles, monitoring a temperature of the mixture, controlling the rate of combining, a maximum temperature of the mixture, or both, and combining the porous metal particles with a polymer to yield a composite. Dealloying includes combining the metallic powder with an etchant to yield a mixture. A metal-polymer composite includes porous metal particles having an average particle size of about 0.2 μm to about 500 μm and a thermoplastic or thermoset polymer. The polymer composite comprises at least 10 vol % of the porous metal particles. A powder mixture includes porous metal particles having an average particle size of about 0.2 μm to about 500 μm and a metal powder. The powder mixture includes about 1 wt % to about 99 wt % of the porous metal particles.

A method of making a metal-polymer composite includes dealloying metallic powder to yield porous metal particles, monitoring a temperature of the mixture, controlling the rate of combining, a maximum temperature of the mixture, or both, and combining the porous metal particles with a polymer to yield a composite. Dealloying includes combining the metallic powder with an etchant to yield a mixture. A metal-polymer composite includes porous metal particles having an average particle size of about 0.2 μm to about 500 μm and a thermoplastic or thermoset polymer. The polymer composite comprises at least 10 vol % of the porous metal particles. A powder mixture includes porous metal particles having an average particle size of about 0.2 μm to about 500 μm and a metal powder. The powder mixture includes about 1 wt % to about 99 wt % of the porous metal particles.