New technologies

Power beam technology

TWI has long been known as experts in laser and electron beam processes, and has a proven track record of this expertise. In the field of electron beam welding TWI staff are actively involved in consultancy and project work for industry in the areas of welding, cutting and surface treatment, feasibility studies and process development, and the development, manufacture and supply of prototype equipment. The development of pulsed electron beam welding is a good example of where TWI is leading the way in process development. The facilities available include numerous electron beam installations with powers ranging from 5 to 150kW, and high vacuum, reduced pressure and non-vacuum processing facilities, with many specialist staff available to provide advice and assistance.

Laser welding

TWI's involvement with laser welding stretches over four decades, and still the frontiers of the technology are being broken. Services are provided to many industry sectors including shipbuilding, automotive and aerospace. Facilities include a large range of CO₂ and Nd:YAG lasers and work handling facilities with the back up of trained staff. A significant amount of work has been done on the development of laser welding procedures for C-Mn steels in shipbuilding, as well as the studying the efficacy of process gases and improving the quality of laser cut edges. TWI has also been involved in the application of lasers to sandwich panels for more than a decade.

Friction processes

Friction based processes have advantages that include low distortion and thermal disruption, and the ability to join dissimilar materials. A number of techniques, which are of interest to ship builders and owners, are part of TWI's core business.

Friction stir welding

Aluminium plate and sections can be welded without distortion by the friction stir welding technique invented and developed by TWI. The low associated distortion is attributed to the low heat input and aluminium section thicknesses range from 1 to 50mm for single pass welding. A number of international shipbuilding companies have adopted the FSW technique for the production of large pre-fabricated aluminium panels typically used for high-speed ferryboats. A portable FSW facility has been developed and successfully used for the welding of an ocean viewer vessel in Australia. Further recent developments include the manufacture of FSW honeycomb panels and seawater resistant panels.

Friction hydro pillar processing is used for the repair of cracks and other defects in thick sections using a consumable tool. This technique is available for a wide range of materials and consumable rods vary in diameter from 10 to 50mm.

Friction surfacing can be used to deposit corrosion resistant surfaces on materials for use in marine environments, and layers can be applied to new or worn components.

TWI's experience of friction welding is extensive and covers all ramifications of the technique - linear, rotary, radial and orbital. The techniques have been proved to produce high quality welds.

Adhesives

The UK's Centre for Adhesive Technology is based at TWI. Adhesives are playing an increasing role in an ever widening range of manufacturing industries including shipbuilding and marine. TWI advises companies on:

applications where adhesives can be used in place of traditional joining methods
selection of adhesives for specific materials
joint design for optimum quality and productivity
bonding procedures and quality assurance.

Innovation

TWI has performed a lot of work in the development of novel materials and joining technologies, and is actively involved in producing innovative ideas and developing these ideas into actual products. The products and processes that are of relevance to the ship industry are: