Membership voice, July - August 2010
TWI's aerospace portfolio has grown rapidly in recent years. A host of technology developments have emanated from its Great Abington HQ as well as projects from its regional offices in Yorkshire, Middlesbrough, and South Wales. Hopefully this brief Membership Voice review will keep you, the Industrial Membership of TWI, up to date on new and emerging technologies related to TWI's aerospace activities.
For example, a novel friction stir welding monitoring system has recently been developed at Abington, from work initiated within the Core Research Programme. The Advanced Rotating Tool Environment Monitoring System (ARTEMIS) offers the possibility of real time FSW flaw detection.
The system is potentially useful for detecting volumetric flaws (voids) in production friction stir welds, and further work will be carried out with customers via a Group Sponsored Project and confidential Single Client Projects.
TWI has also been very active in the linear friction welding area, with the production of blisks for customers. It is also conducting a large programme to join simple titanium parts with the aim of reducing the buy-to-fly ratio.
The development of ultrasonic phased array inspection techniques at TWI Wales, has also proved to be a major step forward.
In the non-fusion joining area TWI will be taking delivery of a production linear friction welding machine in 2011 that will considerably increase its capability in this technology.
Recent work in the fibre laser welding of titanium alloys, looking specifically at the use of a directed side gas jet, has led to much interest in the aerospace industry. High speed observation of the welding process, with and without an optimised directed gas jet, has revealed that it disperses the formation of the vapour plume above the keyhole.
This prevents fluctuations in the keyhole's vaporisation pressure and consequently increases keyhole stability which in turn reduces weld metal porosity.
The development of laser additive manufacture at TWI's Yorkshire facility is continuing with two blown powder, and two powder bed systems in operation to support collaborative and confidential customer projects.
In the arc related processes recent developments in higher productivity welding of titanium and nickel alloys include reduced spatter MIG welding with a novel filler wire, and high frequency pulsed TIG welding, by introducing filler wire directly into the arc rather than the weld pool.
The use of coating technology for depositing metallic coatings on carbon fibre composites for lightning strike and infra-red protection is being reviewed by several aerospace companies. TWI is also pushing forward with the novel microwave curing system which it houses at its Middlesbrough facility to develop curing of composites for the aerospace market.
The Aerospace Industry Panel meetings continue to grow, with the 35th assembly scheduled for 15 September 2010, to coincide with aerospace related Group Sponsored Project meetings.
There is much to look forward to for our aerospace customers, and we remain focused on providing a value added service for them.
Richard Freeman is Aerospace Industry Sector Manager and can be contacted at richard.freeman@twi.co.uk
