The invention relates to a stethoscope comprising a stethoscope chestpiece comprising a body member having a bottom surface and an ejector mark disposed on the bottom surface. The stethoscope chestpiece has a weight of at least 50 g, a surface roughness (Ra) no greater than 1.6 microns in an unpolished state, and reflectivity (% R) of at least 60% in an unpolished state. The stethoscope chestpiece can be produced by injection molding, extruding, or pressing a metallic thermoplastic composition into a mould forming a green molded body, debinding a portion of binder material from green molded body forming a brown molded body without reducing the temperature by more than 80° C., and sintering the brown molded body to form the stethoscope chestpiece.

The invention relates to a stethoscope comprising a stethoscope chestpiece comprising a body member having a bottom surface and an ejector mark disposed on the bottom surface. The stethoscope chestpiece has a weight of at least 50 g, a surface roughness (Ra) no greater than 1.6 microns in an unpolished state, and reflectivity (% R) of at least 60% in an unpolished state. The stethoscope chestpiece can be produced by injection molding, extruding, or pressing a metallic thermoplastic composition into a mould forming a green molded body, debinding a portion of binder material from green molded body forming a brown molded body without reducing the temperature by more than 80° C., and sintering the brown molded body to form the stethoscope chestpiece.

Process for manufacturing a copper part comprising at least the following successive steps: shaping a part by stereolithography, the shaping being carried out by: forming a layer of paste comprising a powder of copper particles, one or more photopolymerizable precursors of a first resin, a photoinitiator and, optionally, an optical additive, photopolymerizing the photopolymerizable precursor(s) of the first resin, the steps and forming a cycle that can be repeated a plurality of times, carrying out a first heat treatment, under an oxidizing atmosphere containing at least 10 vol % of an oxidizer, such as dioxygen, at a first temperature Td so as to eliminate the first resin, and carrying out a second heat treatment, under a reducing atmosphere, at a second temperature Tf, above the first temperature Td, so as to sinter the copper particles to obtain a copper part.

Provided is a sintered bearing (1), including 3 to 12% by mass of aluminum, 0.05 to 0.5% by mass of phosphorus, and the balance including copper as a main component, and inevitable impurities, the sintered bearing (1) having a structure in which an aluminum-copper alloy is sintered with a sintering aid added to raw material powder, a pore (db, do) in a surface layer portion of the sintered bearing (1) being formed smaller than an internal pore (di).

Metal composites, tooling and methods of additively manufacturing these are disclosed. Metal objects and structures as provided herein are additively manufactured from metal having an infill pattern infiltrated with a metal powder. Also provided herein are methods of forming such objects and structures. Methods include additively manufacturing a metal structure having an interior printed using an infill. Steps can further include infiltrating the printed infill of the structure with a powder metal thereby forming a composite.

Textured particles and methods of making the same. A textured particle includes an inner core and a spherical solid outer shell including an outer surface. The inner core is inside the outer shell. The outer surface includes a first tier texture including a first metal, wherein the first metal is greater than 50 atomic % of a total atomic content of all metals in the first tier texture; a second tier texture including the second metal, wherein the second metal is greater than 50 atomic % of a total atomic content of all metals in the second tier texture; and a third tier texture including the third metal, wherein the third metal is greater than 50 atomic % of a total atomic content of all metals in the third tier texture. The first metal, second metal, and third metals are different metals.

Textured particles and methods of making the same. A textured particle includes an inner core and a spherical solid outer shell including an outer surface. The inner core is inside the outer shell. The outer surface includes a first tier texture including a first metal, wherein the first metal is greater than 50 atomic % of a total atomic content of all metals in the first tier texture; a second tier texture including the second metal, wherein the second metal is greater than 50 atomic % of a total atomic content of all metals in the second tier texture; and a third tier texture including the third metal, wherein the third metal is greater than 50 atomic % of a total atomic content of all metals in the third tier texture. The first metal, second metal, and third metals are different metals.

In an aspect, a method for making a metal-containing material comprises steps of: forming a metal-containing hydrogel from an aqueous precursor mixture using a photopolymerization; wherein the aqueous precursor mixture comprises water, one or more aqueous photosensitive binders, and one or more aqueous metal salts; and thermally treating the metal-containing hydrogel to form the metal-containing material; wherein the metal-containing hydrogel is exposed to a thermal-treatment atmosphere during the step of thermally treating; wherein a composition of the metal-containing material is at least partially determined by a composition of the thermal-treatment atmosphere during the thermally treating step.

In an aspect, a method for making a metal-containing material comprises steps of: forming a metal-containing hydrogel from an aqueous precursor mixture using a photopolymerization; wherein the aqueous precursor mixture comprises water, one or more aqueous photosensitive binders, and one or more aqueous metal salts; and thermally treating the metal-containing hydrogel to form the metal-containing material; wherein the metal-containing hydrogel is exposed to a thermal-treatment atmosphere during the step of thermally treating; wherein a composition of the metal-containing material is at least partially determined by a composition of the thermal-treatment atmosphere during the thermally treating step.

A method for producing fine copper particles includes producing fine copper particles having a coating film containing cuprous oxide on a surface by heating copper or a copper compound in a reducing flame formed by a burner. The fine copper particles are produced by adjusting a mixing ratio between a combustible gas and a combustion supporting gas which form the reducing flame such that a volume ratio of CO/CO.sub.2 is in a range of 1.5 to 2.4.