Described herein are compositions, methods, and systems for printing metal three-dimensional objects. In an example, described is a method of printing a three-dimensional object comprising: (i) depositing a metal powder build material, wherein the metal powder build material has an average particle size of from about 10 μm to about 250 μm; (ii) selectively applying a binder fluid on at least a portion of the metal powder build material, wherein the binder fluid comprises an aqueous liquid vehicle and latex polymer particles dispersed in the aqueous liquid vehicle; (iii) heating the selectively applied binder fluid on the metal powder build material to a temperature of from about 40° C. to about 180° C.; and (iv) repeating (i), (ii), and (iii) at least one time to form the three-dimensional object.

Described herein are compositions, methods, and systems for printing metal three-dimensional objects. In an example, described is a method of printing a three-dimensional object comprising: (i) depositing a metal powder build material, wherein the metal powder build material has an average particle size of from about 10 μm to about 250 μm; (ii) selectively applying a binder fluid on at least a portion of the metal powder build material, wherein the binder fluid comprises an aqueous liquid vehicle and latex polymer particles dispersed in the aqueous liquid vehicle; (iii) heating the selectively applied binder fluid on the metal powder build material to a temperature of from about 40° C. to about 180° C.; and (iv) repeating (i), (ii), and (iii) at least one time to form the three-dimensional object.

Various embodiments of the teachings herein include an additive manufacturing method. Some embodiments include: generating a model of a support member using a model of a printing member, wherein at least one portion of the support member is in contact with a lower part of the printing member, and a nitride layer is formed on a surface of the support member; introducing an inert gas into an additive manufacturing printing device, spreading a first material powder in a forming cylinder, performing laser scanning on the first powder using the model; and introducing an ammonia gas into the additive manufacturing printing device, spreading the first material powder in the forming cylinder in the additive manufacturing printing device, performing laser scanning on the first material powder, such that the first material powder is melted, and on the basis of the model of the support member, a nitride layer is formed.

Various embodiments of the teachings herein include an additive manufacturing method. Some embodiments include: generating a model of a support member using a model of a printing member, wherein at least one portion of the support member is in contact with a lower part of the printing member, and a nitride layer is formed on a surface of the support member; introducing an inert gas into an additive manufacturing printing device, spreading a first material powder in a forming cylinder, performing laser scanning on the first powder using the model; and introducing an ammonia gas into the additive manufacturing printing device, spreading the first material powder in the forming cylinder in the additive manufacturing printing device, performing laser scanning on the first material powder, such that the first material powder is melted, and on the basis of the model of the support member, a nitride layer is formed.

A preparation method for a silver-metal oxide electrical contact material, comprising: (1) mixing a silver-containing precursor solution with a metal oxide precursor solution; (2) reacting a reducing agent with the mixed solution to obtain silver powder coated with a metal oxide precursor; (3) heat treating the silver powder in a non-reducing atmosphere to obtain the silver-metal oxide electrical contact material. A preparation device for a silver-metal oxide electrical contact material, a silver-metal oxide electrical contact material prepared by the preparation method, and an electrical contact prepared by the silver-metal oxide electrical contact material. The electrical contact material prepared by the preparation method is at nanoscale, significantly prolonging electrical endurance of the electrical contact.

A three-dimensional (3D) metal object manufacturing apparatus is equipped with a magnetic field generator to form a magnetic field selectively about a nozzle from which melted metal drops are ejected. The drops ejected in the presence of the magnetic field have their velocities reduced from the initial velocity at which they are ejected. The reduced velocity increases the time in flight of the drops before they impact their landing areas. The increased travel time enables the melted metal drops to oxidize sufficiently that they bond less tightly than the drops ejected without passing through the magnetic field. Thus, the apparatus can form metal support structures that adhere less tightly to the part portions of the object so they can be more easily removed after printing of the object.

A lamination molding apparatus including a chamber covering a molding region; a laser beam source to emit a laser beam for sintering a material powder supplied on the molding region to form a sintered layer; and a scan unit to scan the laser beam. The laser beam has one or more spot shapes including at least an elongated shape, and the scan unit is configured to scan the laser beam, of which the spot shape is an elongated shape, in a lateral direction of the elongated shape, is provided.

A lamination molding apparatus including a chamber covering a molding region; a laser beam source to emit a laser beam for sintering a material powder supplied on the molding region to form a sintered layer; and a scan unit to scan the laser beam. The laser beam has one or more spot shapes including at least an elongated shape, and the scan unit is configured to scan the laser beam, of which the spot shape is an elongated shape, in a lateral direction of the elongated shape, is provided.

A cermet and a cutting tool are provided which have high wear resistance and high fracture resistance at a cutting edge even in a mode of cutting where the cutting edge comes to have a high temperature. A cermet 1 includes a hard phase 2 including a carbonitride of one or more kinds of metals selected from Group 4, Group 5, and Group 6 metals of the periodic table including at least Ti and a binder phase 3 containing W and at least one kind of a metal selected from Co and Ni, wherein the binder phase 3 includes a first binder phase 4 in which a mass ratio of W to a total amount of Co and Ni (W/(Co+Ni)) is 0.8 or less and a second binder phase 5 in which a mass ratio of W to a total amount of Co and Ni (W/(Co+Ni)) is 1.2 or more.

A cermet and a cutting tool are provided which have high wear resistance and high fracture resistance at a cutting edge even in a mode of cutting where the cutting edge comes to have a high temperature. A cermet 1 includes a hard phase 2 including a carbonitride of one or more kinds of metals selected from Group 4, Group 5, and Group 6 metals of the periodic table including at least Ti and a binder phase 3 containing W and at least one kind of a metal selected from Co and Ni, wherein the binder phase 3 includes a first binder phase 4 in which a mass ratio of W to a total amount of Co and Ni (W/(Co+Ni)) is 0.8 or less and a second binder phase 5 in which a mass ratio of W to a total amount of Co and Ni (W/(Co+Ni)) is 1.2 or more.