A method for producing a valve seat ring via powder metallurgy may include compacting a powder mixture including 4% by weight to 16% by weight particles of cobalt to form the valve seat ring. The method may also include sintering the powder mixture after compacting the powder mixture. Before compacting the powder mixture, 80% of the particles of cobalt may have a particle diameter of approximately 4.4 μm to 17.5 μm.

A method for joining a first metal part with a second metal part, the metal parts having a solidus temperature above 1100° C., includes applying a melting depressant composition on a surface of the first metal part, the melting depressant composition including a melting depressant component that includes at least 25 wt % boron and silicon for decreasing a melting temperature of the first metal part; bringing the second metal part into contact with the melting depressant composition at a contact point on said surface; heating the first and second metal parts to a temperature above 1100° C.; and allowing a melted metal layer of the first metal component to solidify, such that a joint is obtained at the contact point. The boron at least partly originates from a boron compound selected from any of the following compounds: boric acid, borax, titanium diboride and boron nitride. The melting depressant composition and related products are also described.

A solder joint which is used in power devices and the like and which can withstand a high current density without developing electromigration is formed of a Sn—Ag—Bi—In based alloy. The solder joint is formed of a solder alloy consisting essentially of 2-4 mass % of Ag, 2-4 mass % of Bi, 2-5 mass % of In, and a remainder of Sn. The solder alloy may further contain at least one of Ni, Co, and Fe.

A lead-free solder alloy may comprise tin, silver, copper, bismuth, cobalt, titanium, and antimony. The alloy may further comprise antimony, nickel, or both. The silver may be present in an amount from about 3.1% to 3.8% by weight of the solder. The copper may be present in an amount from about 0.5% to 0.8% by weight of the solder. The bismuth may be present in an amount from about 0.0% (or 1.5%) to about 3.2% by weight of the solder. The cobalt may be present in an amount from about 0.03% to about 1.0% (or 0.05%) by weight of the solder. The titanium may be present in an amount from about 0.005% to about 0.02% by weight of the solder. The antimony may be present in an amount between about 1.0% to about 3.0% by weight of the solder. The balance of the solder is tin.

A method may include removing a portion of a base component adjacent to a damaged portion of the base component to define a repair portion of the base component. The base component may include a cobalt- or nickel-based superalloy, and the repair portion of the base component may include a through-hole extending from a first surface of the base component to a second surface of the base component. The method also may include forming a braze sintered preform to substantially reproduce a shape of the through-hole. The braze sintered preform may include a Ni- or Co-based alloy. The method additionally may include placing the braze sintered preform in the through-hole and heating at least the braze sintered preform to cause the braze sintered preform to join to the repair portion of the base component and change a microstructure of the braze sintered preform to a brazed and diffused microstructure.

The present invention relates to an Ni-based alloy which is excellent in terms of wear resistance and high-temperature corrosion resistance and which includes 0.3≤C≤1.0 mass %, 36.0≤Cr≤50.0 mass %, and 3.0≤Al≤7.0 mass %, with the balance being Ni and unavoidable impurities, and relates to an Ni-based alloy product made of the Ni-based alloy according to the present invention, and methods for producing the Ni-based alloy product.

A bond coating material providing unexpectedly high thermal cyclic fatigue resistance and sulfidation resistance, and unexpectedly prolonged thermal cycle life in high temperature environments of gas turbine engine components with and without the presence of sulfur contains: a) 10% to 30% by weight chromium, b) at least one of tantalum and molybdenum in a total amount of 3% to 15% by weight, c) 5% to 13% by weight aluminum, d) 0.1% to 1.4% by weight silicon, e) 0.1% to 0.8% by weight yttrium, f) 0% to 1.2% by weight carbon, g) 0% to 1% by weight dysprosium, h) 0% to 1% by weight cerium, i) the balance being nickel, and the percentages of a) to i) adding up to 100% by weight. The total amount of tantalum and molybdenum, and the amounts of aluminum and silicon are each critical for avoiding delamination of a top coat from a bond coat.

A bonding and sealing material includes, as the essential ingredients, a solder powder, silver nanoparticles coated with a coating material and a solvent, and additionally includes at least one ingredient selected from the group consisting of selenium metal, oxide film inhibitors and oxide film removers. This bonding and sealing material can easily form under mild conditions a metallic adhesive layer having good hermetic sealability and UV resistance of the sort desired when sealing a short-wavelength light-emitting device such as a UV-LED, and can be stably used over a long period of time.

A micro/nanoparticle-reinforced composite solder for low-temperature soldering and a preparation method thereof belong to the manufacturing field of lead-free low-temperature soldering solders. Micro/nanoparticle-reinforced tin-based alloy solder powder is formed by diffusely mixing micro/nano-sized Cu, Ag and Sb particles with a molten metal tin and atomizing the mixture, and then blended with low-melting-point SnBi-based alloy solder powder and a conventional flux to prepare a micro/nanoparticle-reinforced composite solder. In soldering at a temperature below 200° C., tin atoms in the molten micro/nanoparticle-reinforced tin-based alloy form an intermetallic compound on a soldering pan in preference to the low-melting-point SnBi-based alloy, and the micro/nanoparticles are dispersed in soldered joints to form a “separator effect”, which blocks atoms in the SnBi-based alloy from being precipitated and bonded with the soldering pan, thereby inhibiting the growth of a Bi-rich layer, and solving the problem of brittle and unreliable soldered joints in lead-free low-temperature soldering.

A lead-free silver-free solder alloy may comprise tin, copper, bismuth, cobalt, and antimony. Alternatively, the alloy may comprise gallium in lieu of cobalt. The alloy may further comprise nickel, germanium, or both. The copper may be present in an amount from about 0.5% to 0.9% by weight of the solder. The bismuth may be present in an amount from about 1.0% to about 3.5% by weight of the solder. The cobalt may be present in an amount from about 0.02% to about 0.08% by weight of the solder. Where gallium is used in lieu of cobalt, the gallium may be present in an amount from about 0.2% to about 0.8% by weight of the solder. The antimony may be present in an amount between about 0.0% to about 0.09% by weight of the solder. The balance of the solder is tin.