Mitsubishi Materials Creates 'Step Change' for Aerospace Industry

The global aerospace industry is an ever more important sector for manufacturing and is dominated by the USA and Europe. At the very cutting edge of this industry sector is the Advanced Manufacturing Research Centre (AMRC) with Boeing, a cluster of world class centres for research into advanced manufacturing technologies used in the aerospace industry. For this first issue of the Mitsubishi Materials in-house magazine, our editorial team visited the AMRC to understand how the relationship between Mitsubishi Materials and the AMRC benefits the aerospace sector.

What is the AMRC?

The AMRC in Rotherham near Sheffield, UK, was initially founded in 2001 as a collaboration between the University of Sheffield and Boeing with support from Yorkshire Forward and the European Regional Development Fund. The AMRC cluster has specialist expertise in machining, casting, welding, additive manufacturing, composites and training. It now has over 80 industrial partners that include Boeing, Rolls Royce, BAE Systems, Airbus and of course Mitsubishi Materials. The centre acts as a support mechanism for the aerospace industry, driving technology brands such as Mitsubishi, DMG Mori, Nikken, NCMT, Renishaw, Starrag and many others to develop innovations that enable the aerospace OEMs to hit their targets. Targets that will primarily be to manufacture components and assemblies faster and more efficiently without increasing the shop floor plant list.
To put this philosophy into perspective, by 2032 it is estimated the global industry will demand 29,000 new large civil airliners, 24,000 business jets and 5,800 regional aircraft valued at over US$5 trillion. As a result innovation centres such as the AMRC is driving innovation together with industry to ensure the global airline industry is able to meet these demands. During our visit to the AMRC, we spoke with AMRC Commercial Director and Co-Founder, Mr Adrian Allen OBE who highlighted the initial ambition behind founding the technology centre over ten years ago. As Mr Allen told us: “When Professor Keith Ridgway CBE and I founded the AMRC, one of our key ambitions was to create sustainable wealth for everybody involved. We didn't define wealth purely in monetary terms but in terms of creating highly skilled jobs, value and profit for our partners.
"In the early days we set tangible targets against a timeline, but, after we built our first centre in 2004, we rapidly exceeded our targets and doubled in size within four years. In 2014 we opened our training centre and that has rapidly grown from a first intake of 160 apprentices to the current level of more than 400. One of our initial aims was to generate highly skilled engineering jobs and with this centre, we are realising our ambitions and creating the next generation of UK engineers."
The AMRC now has seven buildings with the latest expansion being the ‚Factory 2050'project. Earmarked to be opened later in 2015, it will be the first fully reconfigurable digital factory in the UK and will take the overall floor area of the AMRC to 38925sq/m.

Adrian Allen OBE AMRC Commercial Director and Co-Founder

What Happens On The AMRC Shop-Floor?

Tom Jones General Manager, MMC Hardmetal U.K. Ltd.

The shop floor at the AMRC is regarded as the industry test bed for the next generation of production technology. The machine tools at the AMRC are provided by either the machine tool manufacturers or the aerospace OEMs. New technological developments for cutting fluids, cutting tools, workholding and toolholding, CAM software and machining strategies as well as new material compositions are all tested to the limit on the machines.
To ensure smooth up-scaling from research to full production, the AMRC uses industry standard machine platforms.
The benefit for the aircraft OEMs is that existing machine tools are optimised by introducing new techniques and strategies without disrupting existing production. For the equipment suppliers, their technology is rigorously tested under conditions that are dictated by the leading names in the aerospace industry. The comprehensive testing of the Mitsubishi Coolstar end mill range is one example.
In 2013 Mitsubishi Materials approached the AMRC regarding membership and shortly after a Tier 2 membership was agreed. Mitsubishi Materials supplies its latest cutting tool innovations and provides technical support to the AMRC engineers. In turn, Mitsubishi is given full results and feedback from the cutting tool trials. Recommendations based on the trials at the AMRC are also part of the process.

What Does Mitsubishi Materials Bring to the AMRC?

Highlighting the importance of Mitsubishi's contribution at the AMRC, Mr Adrian Allen OBE continues: „We are proud and honoured to be working with Mitsubishi Materials. Japanese manufacturers have changed the industrial landscape and the AMRC wouldn't be the facility it is today without our Japanese associations."

"As a commercial entity, we want to be associated with the biggest brands in manufacturing, as that raises our profile and drives the technology enhancements for industry. Mitsubishi is a name that is very well known and highly regarded in Europe. It's a name that brings kudos to the AMRC and helps to build the AMRC brand. We strive for recognition, which leads to respect and eventually earns rewards for all our partners. Behind this, we take a holistic view of the industry and we want the leading global companies involved, so we can utilise the best technologies, products and expertise available. Mitsubishi Materials is one of the key drivers in the progression of cutting tool technology and we would welcome closer collaboration."


What Are The Benefits for Mitsubishi Materials?

With the AMRC providing a unique platform for trialling the latest developments under industry test conditions that are dictated by global aerospace OEMs, the lead engineers at the AMRC deliver results that encompass the complete OEM configuration. These unique test conditions factor in the machine tool, material type and tool path strategies that are often beyond the realms of cutting tool manufacturers'inhouse testing facilities.

For example, the 5-axis Starrag STC1250 at the AMRC is the industry standard for this type of machining and has dynamic capabilities for testing the Coolstar end mill to its maximum.


The Trials

The AMRC has a number of internal research divisions that include the Process Technology Group - covering Structures and Landing Gear, Casings, Shafts and Disks and Blades – and a Composites Centre. At the time of joining the AMRC, Mitsubishi began working with the Structures group on a titanium pocketing project. As the lead engineer involved with the AMRC, Mitsubishi UK‘s Advanced Materials Application Manager, Mr Adrian Barnacle, says: "The AMRC tends to focus upon projects that OEM partners have planned for the future. With aero structural titanium parts, OEMs and the industry in general has focused upon using heavy duty ripper cutters at full machining depth and width parameters with slow feed rates. However, MMC has identified that by machining with smaller cuts at significantly higher speeds/ feeds; in combination with new tool path strategies, cycle times and costs can be significantly reduced. In essence, Mitsubishi Materials is changing this industry perception."

Compiling the data at the AMRC, Mr Daniel Smith trialled Mitsubishi's variable helix multi-flute Coolstar range which was developed around the recent innovations in through flute coolant delivery and increased blank size geometries. Immediate feedback from the AMRC was that the 20mm maximum diameter of the Coolstar was below the industry norm of 25mm, so Mitsubishi developed a 25mm Coolstar for trial purposes.

The AMRC initially trialled a variable helix multi-flute VF6MHVCH Coolstar end mill and set a flank wear of 0.3 as the limit, but this value was never reached. Instead, the selected tool failed due to chipping at the chamfer edge. At this point, it was predicted that with a 3mm corner radius applied it could run for much longer periods and the increased radius would reduce the chances of brittle fracture. It was also apparent that a surface speed of 90m/min was far too low because the flank wear was measured at only 0.1mm after more than 30 minutes of cutting. It was felt that surface speeds of up to 200 m/min could be achievable, and still give acceptable tool life.

From these findings the decision was made to take the straight fluted Mitsubishi tool forward for specific customer funded work where a 3mm corner radius was used.

It was put forward that this type of tool could both rough and finish aero structure parts (pockets specifically) at cut depths of up to 80mm in high speed operations. If successful a potential metal removal rate of 133cm3/min could be achieved.

By optimising the effective radial depth of cut in a process the thermal and mechanical cycles imparted on the tool are controlled, allowing for the ideal parameters to be applied at all times. Observations made during trials showed that a speed of 130m/min and a chip thickness (Hex) of 0.08mm gave the most stable process for the setup used; these provided an estimated initial demo tool life of around 60 minutes at metal removal rates of 133cm3/min.

Daniel Smith | AMRC Structures Platform Group Engineer - Process Technology Group (right) Adrian Barnacle | Advanced Materials Applications Manager, MMC Hardmetal U.K. Ltd. (left)

Mitsubishi Materials Creates a ‚Step Change' In Machining Philosophy

Adam Brown Structures Platform Group Technical Lead - Process Technology Group

Mr Daniel Smith, the AMRC lead engineer on the project stated in his report: "The 25mm development tool has a proven ability to run at elevated surface speeds with little effect on tool life when radial engagement and other temperature generation factors are controlled. Furthermore, speeds of up to 130m/min have been successfully trialled for roughing at ae = 10% of the tool diameter whilst finishing speeds of 160m/min yield an excellent surface finish and could potentially be increased to further reduce cycle times."

Mitsubishi believe the impact this machining strategy and the Coolstar range could have on titanium pocketing applications is considerable.

Adrian Barnacle states: "For pocket machining the Mitsubishi Coolstar is considerably outperforming other tools when using these machining parameters."

AMRC’s Structures Group Technical Lead Mr Adam Brown said: "The support that Mitsubishi has given the AMRC in the short time they have been partners has been extremely useful in terms of tooling development focusing on the needs of the industries we support. We particularly appreciated the engagement with Mitsubishi R&D in producing custom and development tools for testing. In all cases this has led to extremely successful outcomes for both research and application projects."

Adrian Barnacle added: "The aerospace industry has predominantly been the benchmark for heavy machining of difficult materials, however customers now want to reduce on-machine times and stock removal by obtaining components and structures as close to the near net shape as possible. With this mindset, the light and fast machining strategy for the Coolstar is already putting us at the forefront of the industry."

The Results

In tangible terms, this project has benefitted both the AMRC and Mitsubishi Materials. Firstly, it has driven Mitsubishi to extend the Coolstar range with larger diameters and corner radii to meet the industry standards. Additionally, it has given Mitsubishi an insight into the very latest strategies and this information can be used to support the development of future products. The benefit to the AMRC is that it has a better understanding of the characteristics of Mitsubishi’s high performance carbides and geometries which opens the way to new collaboration on industrial projects. It also helps Mitsubishi and the AMRC when they are called upon to give advice on best practice strategies to OEMs.
Adrian Barnacle states, "the benefit to OEM partners as a result of the project will be reduced cycle times, improved surface finishes and reduced tooling costs." All this rounds nicely back to Mr Allen's initial comment about the philosophy of the AMRC generating wealth for all parties involved.

What Does the Future Hold?

The next step is to look at additional AMRC projects, as Mr Adrian Barnacle concludes: "We have only scratched the surface with our potential at the AMRC. This project was with the aero structures division and we are now also turning our attention to the casing and engine division and the composite division. At present, we are very pleased with the Coolstar implementation, which is primarily for small pocket production in titanium. We are now looking at trialling our high feed indexable AJX line of face mill cutters for rough machining larger titanium pockets and also our iMX line of indexable end mills with a screw type head for finish machining of pockets."

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