Electricity + Control

The ACTOM group’s mechanical repair business unit Metalplus and the CSIR’s National Laser Centre (NLC) have agreed to collaborate in marketing and providing a laser-welding service to industry as an extension to the repair services Metalplus already provides.

The two-year collaboration agreement signed in January this year is aimed at further fostering use of fibre laser welding technology as developed by the CSIR NLC to perform specialised mechanical repairs on components that can’t be repaired using conventional welding methods.

Boosting laser welding repair technology2A CSIR NLC technician performs a weld on a shaft, demonstrating some of the special capabilities and advantages offered by laser welding technology.

The well-proven fibre laser welding system performs weld overlays at low input energies and also has low dilution compared with other welding systems.

“It is used for repair of components that have suffered surface damage or wear and to improve the performance of components by changing their surface properties,” explained Hardus Greyling, CSIR NLC Manager, Commercialisation & National Programmes.

“Due to its low heat input and low dilution it is also suitable for performing small-scale repairs and depositing fine layers of metal as weld overlays, which is beyond the scope of the traditional welding systems,” he pointed out, adding that it is also able to weld a variety of alloys.

While occupying a niche market among industrial equipment repair applications, laser welding promises substantial savings to owners and users of high-value equipment.

Boosting laser welding repair technology1From left) Jose Gomes, Metalplus’ General Manager; Corney van Rooyen, CSIR NLC Welding Engineer; and Hardus Greyling, CSIR NLC Manager, Commercialisation & National Programmes.

“Typical examples of components best suited for rebuilding and repair by laser are rebuilding of worn tenons on Stage three power generation turbine blades, providing coil retaining ring landings on generator stator bodies and repairing worn labyrinth seals on compressor screws. This technology is especially well suited to repair of rotational equipment, where components may be at risk of suffering heat-distortion when conventional welding is applied,” Greyling stated.

Laser-welding has about a tenth of the heat input of conventional welding, while its dilution is around five percent, compared with up to 50% in other welding processes.

Metalplus and the CSIR NLC have been collaborating for several years on an ad hoc basis in combining their respective capabilities in serving the mechanical repair market. In some instances operating equipment deployed by clients of Metalplus have required repairs to be done by CSIR NLC welding engineers and technicians using laser-welding technology, while Metalplus has assisted the CSIR NLC with machining services – both for pre-preparation of components in need of repair and for final finishing of components upon completion of laser-welding repair work.

“The collaboration agreement formalises these arrangements, while also providing for close cooperation between us in marketing our respective services in a unified way, mainly to spread the word more widely in the marketplace about the special applications and benefits of laser-welding, including promoting its use where applicable among Metalplus’ existing customers,” said Jose Gomes, Metalplus’ General Manager. 

For further information contact Jose Gomes. Tel +27 (0) 11 433 1880 or email joseg@metal-plus.co.za