TWI Industrial Member Report Summary 607/1997
Resistance surfacing is a novel process, which has been demonstrated for wear and corrosion resistant overlays. It displays the desirable benefits of a full metallurgical bond with minimal dilution, using conventional powder consumables - all of which cannot be achieved by existing technologies of arc welding and thermal spraying.
A number of advantages have been reported for surfacing using electrical resistance heating compared to conventional arc welding processes, including the ability to clad locally with low heat input and low dilution of the overlay. A consumable is applied to a substrate using a resistance welding electrode which provides current pulses and pressure. Resistance heating at the points of contact results in hot compaction and consolidation of the overlay. A number of resistance surfacing processes and applications have been described in literature of the former Soviet Union and Eastern Europe, principally for hardfacing and repair, however, no applications and very little research into the process has been reported elsewhere. In light of the advantages reported for resistance surfacing and the absence of process information from a wide range of sources, trials were undertaken to demonstrate the technology using conventional resistance welding equipment with various metal powders. These included cobalt and nickel.
- To demonstrate use of resistance heating to produce a range of claddings on low carbon steel using standard metallic thermal spraying powders and to evaluate the basic overlay characteristics.
- To demonstrate deposition of metal matrix composite overlays using metal/ceramic powder mixtures and strip cladding consumables by resistance heating.