In an example, a method to form a low work function insert includes preparing a mixture that includes a first powder that contains barium, a second powder that contains calcium, a third powder that contains at least one of aluminum, samarium, or magnesium, and a fourth powder that contains a refractory metal. The method may also include heating the mixture, contained in a crucible, in a furnace. Oxygen concentration in the furnace may be maintained at a low partial pressure during heating of the mixture in the furnace. The low work function of the insert allows electrons to be readily extracted from its surface.

The present invention provides a method (1) of additively manufacturing an article comprising an oxide dispersion strengthened alloy, the method comprising: (5) providing a first powder comprising particles of one or more platinum group metals or an alloy thereof: (10) providing a second powder comprising particles of one or more non-platinum-group metals or metalloids, or one or more alloys thereof: (15) providing a third powder by mixing the first powder and the second powder, the third powder comprising from 0.01 to 1 wt. % of the second powder, based on the total weight of the third powder; and (20) forming an article by a powder bed fusion method using the third powder in an atmosphere comprising from greater than 0 to 2 mol. % oxygen.

A cermet material includes as mass percentages, at least: 50% to 90% of a metallic phase containing an alloy of copper (Cu) and nickel (Ni), and 10% to 50% of an oxide phase containing at least iron, nickel and oxygen with the following proportion by mass of Ni: 0.2%Ni17%.

An electrode, preferably an anode, may include this cermet material.

A cermet material includes as mass percentages, at least: 50% to 90% of a metallic phase containing an alloy of copper (Cu) and nickel (Ni), and 10% to 50% of an oxide phase containing at least iron, nickel and oxygen with the following proportion by mass of Ni: 0.2%Ni17%.

An electrode, preferably an anode, may include this cermet material.

For use on a firearm having a removable ammunition magazine, a longitudinally reciprocating bolt, and a pivoting bolt catch member, the present invention provides an empty ammunition magazine bolt hold open mechanism having a longitudinally extending axel pivotally mounted to the firearm for rotation about a longitudinal axis. The axel has a forward lever arm that extends transversely from the axis and is positioned to be engaged by a magazine follower when the magazine is empty of ammunition. Displacement of the forward lever arm causes rotation of the axel. The axel has a rear portion configured to engage the bolt catch and cause pivotal movement of the bolt catch member when the axel is rotated.

A composite article includes a substrate and a metal-containing layer on the substrate. The metal of the metal-containing layer is oxidizable to a plurality of different oxide phases. The metal-containing layer includes a plurality of phase-specific seed particles promoting formation of a selected one of the different oxide phases.

For use on a firearm having a removable ammunition magazine, a longitudinally reciprocating bolt, and a pivoting bolt catch member, the present invention provides an empty ammunition magazine bolt hold open mechanism having a longitudinally extending axel pivotally mounted to the firearm for rotation about a longitudinal axis. The axel has a forward lever arm that extends transversely from the axis and is positioned to be engaged by a magazine follower when the magazine is empty of ammunition. Displacement of the forward lever arm causes rotation of the axel. The axel has a rear portion configured to engage the bolt catch and cause pivotal movement of the bolt catch member when the axel is rotated.

The valve seat includes an iron-based sintered alloy subjected to oxidation treatment, which is obtained by subjecting an iron-based sintered alloy including: 4 mass % to 15 mass % of Co particles; and hard particles each containing at least one compound of an intermetallic compound, a carbide, a silicide, a nitride, or a boride that has one or more kinds of elements selected from group 4a to 6a elements in a periodic table, and having a hardness of from 600 HV to 1,600 HV to oxidation treatment, and which has an oxide mainly including triiron tetraoxide (Fe.sub.3O.sub.4) and cobalt oxide (CoO) formed on a surface and in an interior of the iron-based sintered alloy. The iron-based sintered alloy subjected to oxidation treatment has an area ratio of the oxide of from 5% to 25% in a cross section thereof in a state prior to installation on the cylinder head.

A process for manufacturing a multi-material part by additive manufacturing, includes the following steps: a) a step of providing a pre-treated metal powder comprising grains and an oxidized and porous layer on a surface of the grains; b) a selective laser powder-bed fusion step comprising implementation of steps i) and ii) as follows: i) a step of forming a layer from the pre-treated metal powder; ii) a step of melting by laser the layer, the melting step being carried out under a reactive atmosphere and comprising changing parameters of application of the laser so that at least a first region of the layer is converted so as to lower the electrical conductivity thereof, thus forming a dielectric, and so that at least a second region of the layer is densified without converting it, the at least a first region being formed when the parameters of application of the laser allow a first energy density to be applied to the first region and/or the laser beam to be kept for a first dwell time on the first region, the at least a second region being formed when the parameters of application of the laser allow a second energy density to be applied to the second region and/or the laser beam to be kept for a second dwell time on the second region, and the first energy density being higher than the second energy density and/or the first dwell time being longer than the second dwell time. A part obtained using the process is also provided.

Methods of making dispersion-hardened platinum compositions include A) producing a melt having at least 70 wt. % platinum, up to 29.95 wt. % of one or more of rhodium, gold, iridium and palladium, between 0.05 wt. % and 1 wt. % of oxidizable non-precious metals in the form of zirconium, yttrium and scandium, and, as the remainder, platinum including impurities, wherein the ratio of zirconium to yttrium in the melt is in a range of from 5.9:1 to 4.3:1 and the ratio of zirconium to scandium in the melt is at least 17.5:1, B) hardening the melt to form a solid body, C) processing the solid body to form a volume body, and D) oxidizing the non-precious metals contained in the volume body by a heat treatment in an oxidizing medium over a time period of at least 48 hours at a temperature of at least 750 C.