The application relates to a low-silver solder for welding an electric vacuum device and a preparation method thereof, The low-silver solder for welding the electric vacuum device is characterized by consisting of Ag, Cu, Ni and a trace element R, wherein the low-silver solder comprises the following components in percentage by mass: 65-71% of Ag, 0-0.1% of Ni, 0-0.1% of trace element R and the balance of Cu; the trace element R consists of one or more of P, Sc, Be, Zr and La. A method of producing the low silver solder, characterized by the steps of: Ag, Cu except from copper foil and Ni are evenly preset in a smelting crucible, the trace elements wrapped by the copper foil are placed above main raw materials consisting of the Ag,Cu except from copper foil and Ni, then smelting and casting are carried out by adopting a vacuum induction smelting furnace, the vacuum degree of a furnace body reaches 10.sup.−1 Pa during smelting and casting, and finally a strip material or a wire materialis prepared by a post treatment process, which has the advantages of good processing performance, good fluidity, low air content in a welding line and excellent thermal stability.

Some implementations of the disclosure are directed to a thermal interface material. In some implementations, a method comprises: applying a solder paste between a surface of a heat generating device and a surface of a heat transferring device to form an assembly; and reflow soldering the assembly to form a solder composite, wherein the solder composite provides a thermal interface between the heat generating device and the heat transferring device, wherein the solder paste comprises: a solder powder; particles having a higher melting temperature than a soldering temperature of the solder paste, wherein the solder paste has a volume ratio of solder powder to high melting temperature particles between 5:1 and 1:1.5; and flux.

Disclosed herein is an electroslag welding wire containing, by mass % based on total mass of the wire: C: more than 0% and 0.07% or less; Si: more than 0% and 0.50% or less; Mn: more than 0% and 1.0% or less; Ni: 6.0 to 15.0%; and Fe: 79% or more. The electroslag welding wire satisfies the following relationship (1): 0.150≤C+Si/30+Mn/20+Ni/60≤0.300 (1).

Disclosed herein is an electroslag welding wire containing, by mass % based on total mass of the wire: C: more than 0% and 0.07% or less; Si: more than 0% and 0.50% or less; Mn: more than 0% and 1.0% or less; Ni: 6.0 to 15.0%; and Fe: 79% or more. The electroslag welding wire satisfies the following relationship (1): 0.150≤C+Si/30+Mn/20+Ni/60≤0.300 (1).

A method of connecting two CMC substrates that includes providing two substrates; placing one substrate approximate to the other substrate, such that at least a portion of the two substrates overlap and define a brazing area; placing a brazing material approximate the brazing area; defining a primary raster pattern that encompasses the brazing area and a portion of the two substrates outside the brazing area; defining a secondary raster pattern that encompasses the brazing area; allowing a laser to scan the primary raster pattern to preheat the brazing area to a temperature below the brazing material's melting point; allowing the laser to scan the secondary raster pattern to heat the brazing area to a temperature that is above the brazing material's melting point; melting and allowing the brazing material to flow within the brazing area; and cooling the brazing area to form a brazed joint connecting the two substrates.

A method of connecting two CMC substrates that includes providing two substrates; placing one substrate approximate to the other substrate, such that at least a portion of the two substrates overlap and define a brazing area; placing a brazing material approximate the brazing area; defining a primary raster pattern that encompasses the brazing area and a portion of the two substrates outside the brazing area; defining a secondary raster pattern that encompasses the brazing area; allowing a laser to scan the primary raster pattern to preheat the brazing area to a temperature below the brazing material's melting point; allowing the laser to scan the secondary raster pattern to heat the brazing area to a temperature that is above the brazing material's melting point; melting and allowing the brazing material to flow within the brazing area; and cooling the brazing area to form a brazed joint connecting the two substrates.

Systems and methods for low-manganese welding alloys are disclosed. An example arc welding consumable may comprise: less than 0.4 wt % manganese; strengthening agents selected from the group consisting of nickel, cobalt, copper, carbon, molybdenum, chromium, vanadium, silicon, and boron; and grain control agents selected from the group consisting of niobium, tantalum, titanium, zirconium, and boron. The grain control agents may comprise greater than 0.06 wt % and less than 0.6 wt % of the welding consumable. The resulting weld deposit may comprise a tensile strength greater than or equal to 70 ksi, a yield strength greater than or equal to 58 ksi, a ductility (as measured by percent elongation) of at least 22%, and a Charpy V-notch toughness greater than or equal to 20 ft-lbs at −20° F. The welding consumable may provide a manganese fume generation rate less than 0.01 grams per minute during the arc welding operation.

A nickel-based brazing foil with a composition consisting essentially of 11 atom %<Cr≤16 atom %, 0 atom %≤Mo≤3.5 atom %, 4 atom %≤B≤5.5 atom %, 11 atom %≤Si≤16 atom %, 0 atom %≤P≤0.5 atom %, 0 atom %≤C≤0.85 atom %, 0 atom %≤Fe≤5 atom %, 0 atom %≤Co≤5 atom %, 0 atom %≤Cu≤2 atom %, 0 atom %≤V≤2 atom %, 0 atom %≤Nb≤2 atom %, incidental impurities of ≤1.0 wt. % and the rest Ni, is provided.

The present disclosure belongs to the field of materials with metal structures, and specifically relates to a preparation method for a nano-oxide dispersion strengthened steel. The method includes mixing a ferrochromium alloy, a ferrotungsten alloy, a ferroalloy containing a rare earth element, an oxygen source and a reduced iron powder to obtain a mixture; wrapping the mixture in a steel strip, and conducting drawing reducing to obtain a flux-cored wire; and conducting arc additive manufacturing on the flux-cored wire on a substrate, and then conducting heat treatment to obtain the nano-oxide particle dispersion strengthened steel.

A semiconductor device includes a semiconductor chip made of a SiC substrate and having main electrodes on one surface and a rear surface, first and second heat sinks, respectively, disposed adjacent to the one surface and the rear surface, a terminal member interposed between the second heat sink and the semiconductor chip, and a plurality of bonding members disposed between the main electrodes, the first and second heat sinks, and the terminal member. The terminal member includes plural types of metal layers symmetrically layered in the plate thickness direction. The terminal member as a whole has a coefficient of linear expansion at least in a direction orthogonal to the plate thickness direction in a range larger than that of the semiconductor chip and smaller than that of the second heat sink.