FRICTION STIR WELDING RESEARCH SERVICES FROM PTG

Posted by on 26 Oct 2016

Only 12 months after the successful launch of its UK-based Friction Stir Welding (FSW) sub-contract welding facility, PTG Heavy Industries is to offer research services to organisations looking to investigate new opportunities for the FSW process.

“Our new sub-contract welding division has proved a considerable success, attracting projects from a number of sectors,” comments Applications Manager, Peter Jowett. “With that in mind, we decided the time was right to extend our offering to include research into welding techniques – particularly when involving small-scale components or the jointing of exotic and particularly difficult to weld alloys. Accordingly, we have installed one of our Crawford Swift Powerstir FSW ‘laboratory’ machines at the facility expressly for that purpose.”

Recognised as a global leader in FSW
Ever since PTG Heavy Industries introduced its range of Crawford Swift Powerstir machines, the company has been recognised as a global leader in Friction Stir Welding. Its new research service uses a ‘latest generation’ Powerstir FSW machine that is capable of welding both flat and cylindrical surfaces.

The choice of research institutes
Research bodies that have invested in Powerstir FSW laboratory machines from PTG Heavy Industries include the globally renowned ISF Welding and Joining Institute at RWTH Aachen University in North Rhine-Westphalia, and The University of Manchester’s Institute of Science and Technology (UMIST).
Vital feedback of performance data

RWTH Aachen University’s research programme includes investigating the potential to accelerate the speed of the Friction Stir Welding process. RWTH Aachen selected the PTG machine for its uncompromising build quality and stability, as well as for its ability to provide real-time data logging – vital feedback of precise performance data, such as production monitoring, force control, weld temperature monitoring and joint tracking. UMIST was one of the very first academic institutions to acquire a Powerstir laboratory machine.

Helping advance FSW technology
“Research departments from across the global aerospace and transport sectors have made Powerstir machines central to their studies into creating stronger, lighter and more aesthetically pleasing welds,” adds Peter Jowett. “It is also worth noting that here in the UK, The Welding Institute uses a Powerstir machine for its ongoing work into FSW processes, joint strength and tool development.”

Excellent results with exotic alloys
As part of its FSW research activities, PTG Heavy Industries has successfully welded aerospace-grade steel alloy and aerospace-grade titanium in thicknesses of 3mm and 8mm, using its fixed pin tooling techniques. PTG Heavy Industries has also achieved excellent results when working with various exotic aluminium alloys, ranging from 2mm to 35mm in thickness, in a number of challenging configurations. These include:

• Longitudinal welding of flat plates, using PTG fixed pin, retracting pin and bobbin ‘floating’ pin tooling technologies
• PTG bobbin tool welding of aluminium aerospace-grade alloys
• Rotary (C axis) welding of flat plates using PTG fixed pin and retracting pin technologies
• Longitudinal seam welding of large diameter cylinders using PTG fixed pin and retracting pin technologies
• Rotary (C axis) radial welding of large diameter cylinders using PTG retracting pin FSW technology
• Rotary (C axis) welding of dome-shaped spheres using PTG retracting pin tool technology
• PTG welding fixtures designed and supplied for all the above welding technologies and component structures / configurations

“As a result of our successes, we especially look forward to applying our findings, approach and technologies to robust testing on other bespoke alloys that are used across the avionics sector,” adds Peter Jowett. “Our new research capability provides considerable opportunities for design engineers looking to balance weight and structural rigidity in order to achieve performance, capability and efficiency in fuselage and component design.”

Superior high-strength joints
Since their launch, Powerstir FSW machines have attracted considerable interest from organisations seeking an innovative way of creating superior high-strength welded joints. Used primarily for jointing aluminium, magnesium, copper, titanium, steel, lead and zinc, the Powerstir FSW process provides a clean, highly aesthetic alternative to traditional welding. It delivers proven weld quality, excellent mechanical properties, virtually no porosity and the opportunity for reduced wall thickness in many applications.

Over recent years, Powerstir models have found particular favour with companies from across the avionics and high-speed rail sectors. In a joint venture with its technology partners, for example, PTG Heavy Industries developed a Powerstir model for use in the manufacture of railway car bodies similar to those used with China’s record-breaking ‘Harmony’ high-speed train. This required the design and build of a Powerstir machine with a 30m x 4m gantry – a machine not only able to produce the longest single FSW railway panel welds in China at over 15 metres in length, but also proof of PTG Heavy Industries’ commitment to meeting each customer’s most exacting requirements.

PTG’s smaller Powerstir laboratory models are typically used for educational and research purposes or for the manufacture of small components. They are particularly suited to welding thin wall sections, such as: hydraulic cylinders, suspension dampers and heat exchanger components.

About Crawford Swift Powerstir Friction Stir Welding
Patented by TWI (The Welding Institute), Friction Stir Welding is a unique and innovative means of jointing metals. The process combines frictional heat with precisely controlled forging pressure to produce extremely high-strength joints that are virtually defect free. Friction Stir Welding transforms the parent metal from a solid to a plasticised state. This occurs during a process that involves mechanically stirring the materials together to form a high-integrity, full-penetration welded joint.

Typical Powerstir FSW applications
• Locomotive train and carriage panels (aluminium)
• Aircraft fuselage and avionics development
• Truck bodies, caravans and space frames
• Heat sinks and electronics enclosures
• Boat and ship panel sections
• Flat and cylindrical fuel tanks and bulk liquid containers
• Aluminium bridge sections, architectural structures and frames
• Pipelines and heat exchangers
• Electrical motor housings

PTG. The first name in precision
Incorporating the brands of Binns & Berry, Crawford Swift, Holroyd and Holroyd Precision Rotors, Precision Technologies Group (PTG) has established itself at the forefront of high precision machine tool design, build and supply. The PTG range includes heavy duty lathes, deep hole drilling machines, Friction Stir Welding (FSW) machines, ultra precision grinding machines for rotor, thread and gear operations; rotor milling machines and special purpose machine tools for the manufacture of precision components. Industrial sectors served range from aerospace, medical and mould tool & die to marine, power generation, mining, oil & gas, steel, high end and heavy automotive. PTG Heavy Industries works closely with The Welding Institute (TWI).
www.holroyd.com