This invention relates to a lead-free solder alloy composition and a method of preparing a lead-free solder alloy, wherein the lead-free solder alloy composition includes a ceramic powder added to a lead-free solder of Sn-(0.1 to 2) wt % Cu, Sn-(0.5 to 5) wt % Ag, or Sn-(0.1 to 2) wt % Cu-(0.5 to 5) wt % Ag. According to this invention, a novel lead-free solder alloy, which functions as a replacement for a conventional lead-free solder, is provided, thus exhibiting superior spreadability, wettability, and mechanical properties than a conventional lead-free solder.

A solder-reinforced bonding system comprises a first substrate (110), a second substrate (120) at least partially in contact with a heating element (400), an adhesive (200) in contact with a first contact surface (115) of the first substrate (110) and a second contact surface (125) of the second substrate (120), and a plurality of solder balls (300) positioned in the adhesive (200) in contact with the first contact surface (115) in a location to receive thermal energy from the heating element (400). A method of producing a solder-reinforced adhesive bond between a first substrate (110) and second substrate (120), comprises (i) applying an adhesive composite (250) including an adhesive (200) and a plurality of solder balls (300) on a first contact surface (115) of the first substrate (110), (ii) connecting a second contact surface (125) of the second substrate (120) to a portion of the adhesive composite (250) opposite the first contact surface (115), and (iii) applying thermal energy from a heating element (400).

A system and method of braze resistance spot welding of an aluminum component to a galvanized steel component involve providing an aluminum-side electrode having a first tip defining a rounded shape, providing a galvanized steel-side electrode having a second tip defining a flat shape, depositing a braze filler material between the aluminum and galvanized steel components at a desired location for a spot weld, performing a pre-heat including providing a first current across the electrodes for a first period such that the braze filler melts and removes a portion of a zinc coating from the galvanized steel component, and after performing the pre-heat, performing a spot weld between the aluminum and galvanized steel components by providing a second current across the electrodes for a second period such that the aluminum melts and the galvanized steel does not melt, wherein the second current is greater than the first current.

[Object] There is provided a flux-cored wire capable of obtaining a weld metal having excellent low temperature toughness and improving welding efficiency, in which preheating performed for preventing cold cracking can be omitted or simplified. [Means for Solving Problems] The flux-cored wire includes one or more of CaF.sub.2, BaF.sub.2, SrF.sub.2, MgF.sub.2, and LiF and, when a total amount thereof is defined as α, the α is 2.0% to 7.0%, by mass %, with respect to a total mass of the flux-cored wire, one or more of a Ti oxide, a Si oxide, a Mg oxide, an Al oxide, a Zr oxide, and a Ca oxide are included in the flux-cored wire, and when a total amount thereof is defined as β, the β is 0.2% to 0.9%, by mass %, with respect to the total mass of the flux-cored wire, a ratio of an amount of the CaF.sub.2 with respect to the α is 0.90 or more, and a ratio of the α with respect to the β is 3.0 or more and 15.0 or less.

The present invention is directed to flux compositions and uses thereof. One composition comprises an activator and a solvent being a glycerol ethoxylate with a molecular weight of 200-500. Another composition comprises an activator, a solvent being a glycerol ethoxylate with a molecular weight of 200-500 and an amine. A soldering method for joining objects is also provided, comprising the steps of applying a flux composition to at least a portion of one or more of the objects, and joining the objects.

The invention provides an ignition flux for arc stud welding, including at least 30 wt % of an active agent, with the active agent selected from a group consisting of SiO.sub.2 and TiO.sub.2. As such, the electric arc can be easily created and smoothly formed. The invention further provides an arc stud welding method utilizing such ignition flux. As such, the fastener and the metal workpiece can be tightly connected together without the need of inserting an ignition tip into the welding portion of a fastener.

Methods for welding a particle-matrix composite body to another body and repairing particle-matrix composite bodies are disclosed. Additionally, earth-boring tools having a joint that includes an overlapping root portion and a weld groove having a face portion with a first bevel portion and a second bevel portion are disclosed. In some embodiments, a particle-matrix bit body of an earth-boring tool may be repaired by removing a damaged portion, heating the particle-matrix composite bit body, and forming a built-up metallic structure thereon. In other embodiments, a particle-matrix composite body may be welded to a metallic body by forming a joint, heating the particle-matrix composite body, melting a metallic filler material forming a weld bead and cooling the welded particle-matrix composite body, metallic filler material and metallic body at a controlled rate.

A flux containing 1 to 10 wt % of an organic sulfonic acid activator, 10 to 40 wt % of a high-molecular-weight nonionic surfactant that is a nonionic surfactant having a mass-average molecular weight Mw of more than 1200 and 5 to 75 wt % of a low-molecular-weight nonionic surfactant that is a nonionic surfactant having a mass-average molecular weight Mw of 1200 or less, in which the content of the low-molecular-weight nonionic surfactant is equal to or larger than the content of the organic sulfonic acid activator. This flux contains no cationic surfactant or contains more than 0 wt % and 5 wt % or less of the cationic surfactant. A solder paste containing this flux and a Sn-based solder metal.

A solder includes a Sn alloy phase and a particle. The particle has a higher Young's modulus than the Sn alloy phase. The particle has a lower linear expansion coefficient than the Sn alloy phase. An electronic component includes a metal terminal joined thereto with the solder.

A method for manufacturing a soldered product by soldering a solder object portion, including: a solder supplying step that causes a cylindrical soldering iron having a through hole to contact with the solder object portion to supply a thread solder piece to the solder object portion from the through hole; a heating step that heats the thread solder piece with the cylindrical soldering iron and causes to melt the thread solder piece at the solder object portion; and a curing step that cures a melting object of the thread solder piece to solder the solder object portion. The thread solder piece is composed of a core containing a flux and a coating member containing a solder alloy that covers the core. The flux has a rosin having an acid value which is substantially as a main component thereof.