Fluxless soldering

Abstract

Soldering without the use of liquid fluxes is frequently demanded for assembly of electronic, optical and mechanical components because these chemicals and their residues can adversely affect performance. Chemical fluxes operate by removing oxide films from metal surfaces, which otherwise impede the spreading and wetting that is so essential for successful soldering and joint formation. Fluxless soldering processes employ alternative strategies to achieve the same end. Typically the oxide films are removed by reduction, displacement or dissolution; alternatively they are simply prevented from forming in the first place by suitably modifying the surfaces of the joints. The range of conditions required for successful fluxless soldering and how these are being achieved are reviewed with reference to specific case studies described in the scientific and technical literature.

Modelling of specific grinding energy for Inconel 718 superalloy

“…Titanium (Ti)-based braze alloy is more suitable which has an excellent wetting property even to the ceramic surface due to the formation of titanium oxide (TiO) which has exquisite wettability nature. 34 Typically around 900 °C, Ti reacts with non-metal and forms oxide which has excellent wetting nature. In the present work, Ticusil has been used as ABA for brazing alumina grits over the steel shanks.…”

Focussed arc tungsten inert gas brazing of zinc-coated steels

“…The filler material acts as a wetting agent for the mating surfaces of the joint that leads to formation of a metallurgical bond between filler and the mating surfaces of the parent material. 2 The main goal of using this method is to join the structural steel panels to form the BIW while maintaining the corrosion resistance offered by the zinc coating. 3 The welding plasma, brazing speed and filler wire speed need to be closely controlled to ensure optimum filler wire melting while minimising damage to the zinc coating.…”