Techniques for using additive manufacturing (AM) to fabricate creep resistant ferritic/martensitic steel with improved high temperature strength are described. AM processing may be performed on Grade 91 steel powder. Beam powers from about 221 W to about 270 W may be used. Traverse rates from about 675 mm/s to about 825 mm/s may be used. Heat inputs ranging from about 55.7 J/mm.sup.3 to about 83.2 J/mm.sup.3 may be produced. Creep resistant ferritic/martensitic steel, produced according to the present disclosure, has improved strain yield strength and ductility as compared to wrought steel.

This invention discloses a boron-containing titanium-based composite powder for 3D printing, consisting of 0.5%-2% by weight of titanium diboride and 98%-99.5% by weight of titanium sponge. The invention further discloses a method of preparing such composite powder, where the element boron is introduced to the titanium powder through rapid solidification, which significantly improves the solid solubility of boron in Ti, enabling the introduction of part of the boron into the titanium matrix to form supersaturated solid solutions. The reinforcement phase TiB in the boron-containing titanium-based composite powder prepared herein can be precisely controlled in grain size ranging from the nanometer scale to the micrometer scale through temperature or energy density, thereby preparing the titanium-based composite materials with different sizes of reinforcement phases to meet different mechanical requirements.

This invention discloses a boron-containing titanium-based composite powder for 3D printing, consisting of 0.5%-2% by weight of titanium diboride and 98%-99.5% by weight of titanium sponge. The invention further discloses a method of preparing such composite powder, where the element boron is introduced to the titanium powder through rapid solidification, which significantly improves the solid solubility of boron in Ti, enabling the introduction of part of the boron into the titanium matrix to form supersaturated solid solutions. The reinforcement phase TiB in the boron-containing titanium-based composite powder prepared herein can be precisely controlled in grain size ranging from the nanometer scale to the micrometer scale through temperature or energy density, thereby preparing the titanium-based composite materials with different sizes of reinforcement phases to meet different mechanical requirements.

A method comprises providing a molten aluminum alloy selected from the group consisting of 6000 series aluminum alloys comprises chromium (Cr) in a range of between 0.001 wt % to 0.05 wt %. The molten aluminum alloy is formed into a formed body having beta-AlFeSi particles. The formed body is solution heat treated at a temperature in a range of 1,025-1,050° F. to form a heat-treated body. The solution heat treating transforms substantially all of the beta-AlFeSi particles into alpha-AlFeSi particles such that the heat-treated body is substantially free of the beta-AlFeSi particles.

A production method for an alloy member having mainly high hardness and high resistance to corrosion and produced by an additive manufacturing method, the alloy member, and a product using the alloy member are provided. The production method for an alloy member includes: an additive manufacturing step of forming a shaped member through an additive manufacturing method using an alloy powder containing elements Co, Cr, Fe, Ni, and Ti each in a range of 5 atom% to 35 atom% and containing Mo in a range exceeding 0 atom% and 8 atom% or less, the remainder being unavoidable impurities; and a heat treatment step of holding the shaped member in a temperature range higher than 500° C. and lower than 900° C. directly after the additive manufacturing step without undergoing a step of holding the shaped member in a temperature range of 1080° C. to 1180° C.

An aluminum alloy substrate for magnetic disks, including an aluminum alloy containing: 1.0 to 6.5 mass % of Mg; and the balance consisting of Al and unavoidable impurities, in which the distribution of Si—K—O-based particles with a longest diameter of 1 μm or more adhering to the surface from the surrounding environment is equal to or less than one particle/6,000 mm.sup.2; and in which the distribution of Ti—B-based particles with a longest diameter of 1 μm or more present on the surface is equal to or less than one particle/6,000 mm.sup.2, and a magnetic disk using the aluminum alloy substrate for magnetic disks.

The present invention relates to a high-strength, high-corrosion resistance ternary magnesium alloy and a preparation method therefor, the magnesium alloy comprising the following element components by mass percentage: 8-12 wt % of Y, 0.6-3 wt % of Al and the remainder being Mg. The method comprises: (1) under a protective atmosphere, preparing a Mg—Y intermediate alloy, an aluminum ingot and a magnesium ingot into a magnesium alloy melt; (2) under a protective atmosphere, allowing the magnesium alloy melt to stand after stirring, then carrying out refining, degassing, and slag removal, allowing the magnesium alloy melt to stand again, then thermally insulating to obtain a magnesium alloy liquid; and (3) casting and molding the magnesium alloy liquid under a protective atmosphere, and forming a cast ingot; the three steps above ultimately obtain a high-strength, high-corrosion resistance ternary magnesium alloy.

Disclosed is a processing technology for inhibiting weld coarse grains of magnesium alloy profiles, including the following steps: preparation of a magnesium alloy ingot, homogenization, scalping, extrusion, pre-stretching at room temperature, solution treatment, quenching, stretching correction, artificial aging, etc. The processing technology can effectively control the production of weld coarse grains in extrusion and heat treatment processes of magnesium alloy profiles, and all property indexes of final products are higher than standard requirements.

A spark plug having a center electrode that includes a columnar noble metal tip at one end thereof, and a ground electrode that forms a spark gap between the ground electrode and a circular discharge surface of the tip. In the tip, a mass % of Pt is largest and a content percentage of Ni is more than or equal to 0 mass % and less than or equal to 40 mass %. In each of both a cross-section of the noble metal tip parallel to the discharge surface and a cross-section of the tip perpendicular to the discharge surface, particles each having an aspect ratio of more than or equal to 1 and less than or equal to 10 occupy more than or equal to 70% of observed particles in an area extending from an outline of the cross-section by a distance of 10% of a diameter of the discharge surface.

A seal member includes a γ′ precipitation-hardening alloy, in which the γ′ precipitation-hardening alloy has a component composition of, in mass %: Ni: from 40 to 62%; Cr: from 13 to 20%; Ti: from 1.5 to 2.8%; Al: from 1.0 to 2.0% (provided that Ti/Al: 2.0 or less); Nb: 2.0% or less; Ta: 2.0% or less (provided that Nb+Ta: from 0.2 to 2.0%); B: from 0.001 to 0.010%; W: 3.0% or less; and Mo: 2.0% or less (provided that Mo+(1/2)W: from 1.0 to 2.5%), and optionally, C: 0.08% or less; Si: 1.0% or less; Mn: 1.0% or less; P: 0.02% or less; and S: 0.01% or less, with the balance being Fe and inevitable impurities, and in which the seal member has a hardness of 250 Hv or more, and includes a cold-rolled microstructure obtained by a cold rolling.