A cemented carbide includes a hard phase and a binder phase, wherein the hard phase has first hard phase grains each composed of tungsten carbide, second hard phase grains including a core portion and a rim portion, a composition of the core portion is represented by M1.sub.x1W.sub.1-x1C.sub.1-y1N.sub.y1, a composition of the rim portion is represented by M2.sub.x2W.sub.1-x2C.sub.1-y2N.sub.y2, each of the M1 and M2 is at least one metal element selected from a group consisting of a group 4 element, a group 5 element in a periodic table, chromium and molybdenum, and the binder phase includes at least one iron group element selected from a group consisting of iron, cobalt and nickel, and a 50% cumulative number grain size of the second hard phase grains is 0.01 ?m or more and 1.0 ?m or less.

A cemented carbide includes a hard phase and a binder phase, wherein the hard phase has first hard phase grains each composed of tungsten carbide, second hard phase grains including a core portion and a rim portion, a composition of the core portion is represented by M1.sub.x1W.sub.1-x1C.sub.1-y1N.sub.y1, a composition of the rim portion is represented by M2.sub.x2W.sub.1-x2C.sub.1-y2N.sub.y2, each of the M1 and M2 is at least one metal element selected from a group consisting of a group 4 element, a group 5 element in a periodic table, chromium and molybdenum, and the binder phase includes at least one iron group element selected from a group consisting of iron, cobalt and nickel, and a 50% cumulative number grain size of the second hard phase grains is 0.01 ?m or more and 1.0 ?m or less.

A heat exchanger and method for making a heat exchanger assembly is described, involving generating a digital model of a heat exchanger assembly that comprises a heat exchanger core within a housing. The digital model is inputted into an additive manufacturing apparatus or system comprising an energy source. The additive manufacturing apparatus applies energy from the energy source to successively applied incremental quantities of a metal powder, which fuses the powder to form incremental portions of the heat exchanger core and housing according to the digital model. Unfused or partially fused metal powder is enclosed in a first region of the heat exchanger assembly between the heat exchanger core and the housing.

A heat exchanger and method for making a heat exchanger assembly is described, involving generating a digital model of a heat exchanger assembly that comprises a heat exchanger core within a housing. The digital model is inputted into an additive manufacturing apparatus or system comprising an energy source. The additive manufacturing apparatus applies energy from the energy source to successively applied incremental quantities of a metal powder, which fuses the powder to form incremental portions of the heat exchanger core and housing according to the digital model. Unfused or partially fused metal powder is enclosed in a first region of the heat exchanger assembly between the heat exchanger core and the housing.

A method for making a heat exchanger assembly is described, involving generating a digital model of a heat exchanger assembly that comprises a heat exchanger core within a housing. The digital model is inputted into an additive manufacturing apparatus or system comprising an energy source. The additive manufacturing apparatus applies energy from the energy source to successively applied incremental quantities of a metal powder, which fuses the powder to form incremental portions of the heat exchanger core and housing according to the digital model. Unfused or partially fused metal powder is enclosed in a first region of the heat exchanger assembly between the heat exchanger core and the housing.

A method for making a heat exchanger assembly is described, involving generating a digital model of a heat exchanger assembly that comprises a heat exchanger core within a housing. The digital model is inputted into an additive manufacturing apparatus or system comprising an energy source. The additive manufacturing apparatus applies energy from the energy source to successively applied incremental quantities of a metal powder, which fuses the powder to form incremental portions of the heat exchanger core and housing according to the digital model. Unfused or partially fused metal powder is enclosed in a first region of the heat exchanger assembly between the heat exchanger core and the housing.

A silver particle synthesizing method includes reducing a dispersant from first silver particles each covered with the dispersant to obtain second silver particles. The method further includes synthesizing third silver particles each having a larger particle diameter than the second silver particles by causing a reaction between a silver compound and a reductant in a liquid phase containing the second silver particles.

A silver particle synthesizing method includes reducing a dispersant from first silver particles each covered with the dispersant to obtain second silver particles. The method further includes synthesizing third silver particles each having a larger particle diameter than the second silver particles by causing a reaction between a silver compound and a reductant in a liquid phase containing the second silver particles.

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer formed on a surface thereof, and the boding wire contains one or more elements of As, Te, Sn, Sb, Bi and Se in a total amount of 0.1 to 100 ppm by mass. The bonding longevity of a ball bonded part can increase in a high-temperature and high-humidity environment, improving the bonding reliability. When the Cu alloy core material further contains one or more of Ni, Zn, Rh, In, Ir, Pt, Ga and Ge in an amount, for each, of 0.011 to 1.2% by mass, it is able to increase the reliability of a ball bonded part in a high-temperature environment of 170 C. or more. When an alloy skin layer containing Au and Pd is further formed on a surface of the Pd coating layer, wedge bondability improves.

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer formed on a surface thereof, and the boding wire contains one or more elements of As, Te, Sn, Sb, Bi and Se in a total amount of 0.1 to 100 ppm by mass. The bonding longevity of a ball bonded part can increase in a high-temperature and high-humidity environment, improving the bonding reliability. When the Cu alloy core material further contains one or more of Ni, Zn, Rh, In, Ir, Pt, Ga and Ge in an amount, for each, of 0.011 to 1.2% by mass, it is able to increase the reliability of a ball bonded part in a high-temperature environment of 170 C. or more. When an alloy skin layer containing Au and Pd is further formed on a surface of the Pd coating layer, wedge bondability improves.