In various embodiments, a metal alloy resistant to aqueous corrosion consists essentially of or consists of niobium with additions of tungsten, molybdenum, and one or both of ruthenium and palladium.

A method for producing a metal ingot by using an electron-beam melting furnace having an electron gun and a hearth that accumulates a molten metal of a metal raw material, wherein the metal raw material is supplied to the position on a supply line disposed along a second side wall of the hearth that accumulates the molten metal of the metal raw material. A first electron beam is radiated along a first irradiation line that is disposed along the supply line and is closer to a central part of the hearth relative to the supply line on the surface of the molten metal, wherein a surface temperature (T2) of the molten metal at the first irradiation line is made higher than an average surface temperature (T0) of the entire surface of the molten metal in the hearth.

A metal purifying method having: a local heating step of heating an aluminum-based molten metal in a first region on a molten metal surface of the aluminum-based molten metal; and a local low pressure step of lowering the pressure in a second region on the molten metal surface to a pressure lower than the pressure in the first region. The second region is different from the first region. This allows a specific element to be vaporized from the second region to purify the aluminum-based molten metal. The specific element is one or more of Zn, Mg, or Pb having a saturated vapor pressure higher than that of Al. This is effective not only in a purifying method for removing a specific element from an aluminum-based molten metal but also in a method of recovering a specific element, which can be a resource, from an aluminum-based molten metal.

In various embodiments, a metal alloy resistant to aqueous corrosion consists essentially of or consists of niobium with additions of tungsten, molybdenum, and one or both of ruthenium and palladium.

In various embodiments, a metal alloy resistant to aqueous corrosion consists essentially of or consists of niobium with additions of tungsten, molybdenum, and one or both of ruthenium and palladium.

High quality titanium ingot is produced by using recovered titanium scrap as a raw material and adding additives. Scrap, each having individual information of identification and process profile information, is passed through automatic reading means to obtain the information and to store it in a data server. A calculating means calculates a combination of the scrap, titanium sponge and additives and feed rate of each of them so as to satisfy chemical composition and producing rate of a target ingot product using the individual identification pieces of information stored in the data server, during a beginning step of the ingot production, and transmits electrical signals corresponding to calculated results of the combination and the feed rates from the calculating means to a feed rate controlling means of each feed means of the titanium scrap, titanium sponge, and additives and then starting supply of them, and detecting means equipped at an extracting part of the ingot product reads actual producing rate of the ingot product, after the beginning step of the ingot production. The calculating means controls feed rate of the titanium scrap, titanium sponge, and/or additives based on the actual producing rate.

Provided is a titanium cast product made of commercially pure titanium, the titanium cast product being produced by electron-beam remelting or plasma arc melting, comprising: a melted and resolidified layer in a range of 1 mm or more in depth at a surface serving as a surface to be rolled, the melted and resolidified layer being obtained by adding one or more kinds of β stabilizer elements to the surface and melting and resolidifying the surface. An average value of β stabilizer element(s) concentration in a range of within 1 mm in depth is higher than β stabilizer element(s) concentration in a base material by, in mass %, equal to or more than 0.08 mass % and equal to or less than 1.50 mass %. As the material containing the β stabilizer element, powder, a chip, wire, or foil is used. As means for melting a surface layer, electron-beam heating and plasma arc heating are used.

A method for preparing high-purity nickel-based superalloy includes the steps of: performing electron beam smelting on small cylinders in a first water-cooled copper crucible after preheating an electron gun, and converging the beam to the edge of one side of the ingot; turning on the electron gun again after completely solidifying the ingot, the electron beam spot uniformly and slowly scanning a surface of the ingot from a side opposite to a final beam converging area of the ingot to the final beam converging area of the ingot to ensure that the alloy at a position scanned by the electron beam spot is completely melted, and stopping scanning once scanning to the final converging area of the ingot; casting the molten alloy in the first water-cooled copper crucible to the second water-cooled copper crucible; taking out the refined nickel-base superalloy after cooling down the electron beam melting furnace.

An electron beam melting furnace includes a hearth, a mold, an electron gun for keeping metal as a molten state, an electron beam controller for controlling direction of the electron beam, an image sensor for molten metal, and an operating device. A method for operating the furnace includes a step of inputting electron beam emitting coordinates in the electron beam controller, a step of emitting the electron beam, a step of detecting a high electron beam intensity spot by the image sensor, a step of calculating coordinates of high electron beam intensity based on the detected signal by the operating device, a step of calculating differences between the coordinates of emission and the coordinates of high electron beam intensity spot, a step of inputting the difference in the electron beam controller, and a step of controlling the location of electron beam spot.

The present disclosure relates to a method of manufacturing a powder for additive manufacturing. The method comprises steps of: vaporising a precursor metal material to form a metal vapor, wherein the precursor material includes a metal alloy and inclusions, and vaporising the alloy includes heating the precursor material to a temperature above the boiling point of the metal alloy and below the boiling point of the inclusions; condensing the metal vapor to form a molten metal; and atomizing the molten metal to form a metal powder. The present disclosure also relates to an apparatus for carrying out the method.