A mass flow controller and mass flow meter are disclosed. The mass flow controller and mass flow meter include a sensor tube configured to transport a fluid, and an upstream heater element and a downstream heater element which are formed of heating resistance wires provided in an outer periphery of the sensor tube. At least one weld terminal is electrically connected to an end of one or more of the heating resistance wires by spot welding material. A temperature difference between the melting point of the weld terminal and a melting point of the heating resistance wires does not exceed 100 degrees Celsius, and one or more coat layer(s) is provided on a surface of the weld terminal.

A welding assembly including a current generator, a first electrode electrically coupled to the current generator, the first electrode including a first engagement surface, a second electrode electrically coupled to the current generator, the second electrode including a second engagement surface, a width-determining fixture positioned between the first electrode and the second electrode to define a welding volume having a width, and an electrically nonconductive material positioned to electrically insulate at least one of the first electrode and the second electrode from an electrical conductor outside the width.

Aluminum-base alloy workpieces have surfaces with films of aluminum oxide which inhibit good contact with weld faces of resistance spot weld electrodes and the faying surfaces of, for example, sheet workpieces stacked for welding. Sometimes, the surfaces of the sheets also are coated with an adhesive or a sealer which further complicates welding. But in accordance with this invention, weld faces of opposing, round, copper welding electrodes are pressed against opposite outside surfaces of the sheets at a spot weld site and weld current is applied to the electrodes in accordance with a three-stage weld schedule to better form each weld. The weld schedule comprises a Conditioning stage (stage 1), a weld nugget Shaping stage (stage 2), and a weld nugget Sizing stage (stage 3).

It is an objective of the invention to provide a conductive joint article exhibiting electrical joinability comparable to that of solder joining of easy-to-solder joinable metals even when a joined member of the conductive joint article is made of a hard-to-solder joinable metal. There is provided a conductive joint article with conductive joined members electrically joined via a joining layer, at least one of the joined members being made of a hard-to-solder joinable metal. The joining layer comprises an oxide glass phase and a conductive metal phase. The oxide glass phase includes vanadium as a major constituent and at least one of phosphorus, barium and tungsten as an accessory constituent, and has a glass transition point of 390 C. or less. And, connection resistance between the joined members exhibits less than 110.sup.5 /mm.sup.2.

It is an objective of the invention to provide a conductive joint article exhibiting electrical joinability comparable to that of solder joining of easy-to-solder joinable metals even when a joined member of the conductive joint article is made of a hard-to-solder joinable metal. There is provided a conductive joint article with conductive joined members electrically joined via a joining layer, at least one of the joined members being made of a hard-to-solder joinable metal. The joining layer comprises an oxide glass phase and a conductive metal phase. The oxide glass phase includes vanadium as a major constituent and at least one of phosphorus, barium and tungsten as an accessory constituent, and has a glass transition point of 390 C. or less. And, connection resistance between the joined members exhibits less than 110.sup.5 /mm.sup.2.

A bonded body is provided that is formed by bonding a metal member formed from copper, nickel, or silver, and an aluminum alloy member formed from an aluminum alloy of which a solidus temperature is lower than a eutectic temperature of aluminum and a metal element that constitutes the metal member. The aluminum alloy member and the metal member are subjected to solid-phase diffusion bonding. A chill layer, in which a Si phase of which an aspect ratio of a crystal grain is 2.5 or less and a crystal grain diameter is 15 m or less is dispersed, is formed on a bonding interface side with the metal member in the aluminum alloy member. The thickness of the chill layer is set to 50 m or greater.

A welding assembly including a current generator, a first electrode electrically coupled to the current generator, the first electrode including a first engagement surface, a second electrode electrically coupled to the current generator, the second electrode including a second engagement surface, a width-determining fixture positioned between the first electrode and the second electrode to define a welding volume having a width, and an electrically nonconductive material positioned to electrically insulate at least one of the first electrode and the second electrode from an electrical conductor outside the width.

A method for welding a stack of sheets having a plurality of sheets of different materials is provided. In an aspect, the stack of sheets includes an aluminum sheet and a galvanneal steel sheet. In an aspect, the method includes resistively spot welding the galvanneal sheet to a hot-stamped steel sheet placed between the aluminum sheet and the galvanneal sheet, the sheet of hot-stamped steel including stress relief sections. The method further includes placing a metal foil on the aluminum sheet and vaporizing the metal foil to project portions of the aluminum sheet through the stress relief sections of the hot-stamped steel sheet to weld the portions of the aluminum sheet to the galvanized steel sheet. In another aspect, the method includes placing the metal foil on a raised portion of the aluminum sheet and projecting the raised portion of the aluminum onto the galvanneal steel sheet.

A welding process for the welding of aluminum includes a force sensor measuring a force between two welding electrodes on aluminum elements to be welded and transmitting its measured values to a welding control. Until the elapse of a set welding time, the welding control calculates and stores at least one absolute value and/or at least one increase in the measured force. The welding control compares the measured absolute value and/or the increase in the measured force with a reference value and/or a reference curve and calculates a control deviation from the comparison. After the elapse of the set welding time, the welding control subjects the welding electrodes to a constant current during a welding time extension that follows the set welding time, dependent on a magnitude of the control deviation that is measured at the point in time of the elapse and/or during the set welding time.

A self-piercing riveting system includes a localized melting system that locally melts a target location on a metal substrate and a driver that drives a rivet into to the metal substrate after the target location is locally melted. A method of forming a joint with a self-piercing riveting system includes locally melting a target location on the at least two metal substrates. The method also includes driving a rivet into the target location, optionally with a driver, after locally melting the target location such that the rivet pierces the at least two metal substrates at the target location.