3D printing titanium in aerospace

3d_printing_titanium_in_aerospace
Airbus's first A330neo (new engine option), an A330-900, starts its final assembly process on the final assembly line at Toulouse (27 September 2016).

Most activity in the titanium metal industry is being driven by increased demand from the aerospace industry. As jet engines burn at ever higher temperatures to improve speed and efficiency, titanium use will increase. Its use in airframes will be driven largely by increased use of CFCs.

By James Chater

A transition is taking place in which older aircraft are being phased out in favour of lighter, more fuel-efficient planes. Demand from Asia, particularly China, is expected to remain especially strong.

Airbus versus Boeing

Rivalry is intense and sometimes bitter between Airbus and Boeing, which continue to be the two dominant producers of commercial aircraft. Fierce arguments rage as to the relative merits of each of their aircraft, with regard to such features as efficiency, mileage and seat capacity.

Among single-aisle planes, Airbus received EASA and FAA certification for its A321neo, the largest of its popular A320neo family. They are equipped with a choice of CFM’s LEAP-1A or Pratt & Whitney’s PurePower PW1100G-JM engines. Ducommun received a multi-year contract to supply titanium parts for the engine support and engine frames.

Competing with the Airbus A321neo is the Boeing 737 Max 10X, images of which were unveiled on 7 March 2017. Boeing states that the 737 Max 10 will offer the same capacity as the slightly longer Airbus A321neo, but with lower fuel consumption and slightly greater range. On the same day its 737 MAX 9, which expands seat capacity to 220 passengers and range to 3,515 nautical miles, completed its maiden flight. It is scheduled to enter service in 2018.

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Boeing begins final assembly on the first 787-10 Dreamliner at its facility in South Carolina, December 2016.

With regard to wide-body planes, the A330-800neo and A330-900neo reached final assembly stage in September 2016. Both feature Sharklet wingtip devices that improve aerodynamics and incorporate Rolls-Royce 7000 jet engines. The Airbus A350-1000, the largest of the A350 family, completed its first flight on 24 November 2016 and is scheduled to enter service in the second half of 2017. It is powered by Rolls-Royce’s new Trent XWB-97 engines.

Meanwhile, Boeing continues work on the third of its 787 Dreamliner range. Final assembly on the first 787-10 began in December 2016. This plane offers 14% more seats and 15% more cargo compared to the Boeing 787-9. First flight is expected in 2017 and first delivery in 2018.

Building on the success of its 777 and 787 ranges is Boeing’s newest offering, the 777X twin-aisle aircraft, which will compete with the Airbus A350. Its composite wings and advanced GE9X engines promise greater fuel efficiency. It will be offered in two variants, the 777-8 and 777-9, with a possible addition of a larger variant, the 777-10, which will compete with the Airbus A380 (super-jumbo). Manufacture will soon begin at a facility in St. Louis opened on 13 October 2016. First delivery is expected in 2020. Repair facilities for the GE9X are planned for Cardiff in Wales and Legnica in Poland.

Other aircraft

With aerospace demand rising in China, the country is keen to develop its own models to compete with Airbus and Boeing. To this end Comac is planning a family of 158- to 174-seat narrow-body jet airliners, the C919. It is similar to the Airbus A320. Design and assembly will be carried out in Shanghai using foreign-made jet engines (a version of CFC’s LEAP) and avionics, but China wishes eventually to produce a domestically made engine.

“Titanium alloys have often be used to cold-form the tubes of exhaust systems in racing cars and racing bikes. However, the high cost of Ti alloys has so far inhibited their use. All this is changing, as scientists find ways to improve the strength of already existing Ti alloys.”

The C919 will have two variants: a standard one with a range of 2,200 mlies and an extended-range version able to fly 2,999 miles. Similar is Embraer’s E-Jet E2 family, consisting of three narrow-body medium-range jet airliners. They will use Pratt & Whitney PW1000G geared turbofans in two sizes. The E195-E2 was rolled out on 7 March 2017, the same day as the Boeing 737 MAX 9. The changes compared to previous of the E-Jet E2 family include an increase in the aircraft’s maximum take-off weight and an extension of its wing span.

In Canada, Bombardier’s C Series narrow-body planes entered service on 15 July 2016 with Swiss Global Air Lines. These aircraft are unusual in catering for the 100-150 seat range. They are fitted with Pratt & Whitney PurePower® PW1500G engines that reduce emissions, noise and fuel burn. In a bid to build on this success, Canada announced it is providing repayable investments to Bombardier over a period of four years.

Conclusion

Titanium will continue to be in demand in a number of industries, including marine applications, nuclear, desalination, auto, medical, architecture and sculpture; also in musical instrument fabrication and leisure activities such as sports and camping. We may single out the auto industry because its priorities are similar to those of aerospace: lightness and fuel heat resistance as means towards greater fuel efficiency.

Titanium alloys have often be used to cold-form the tubes of exhaust systems in racing cars and racing bikes. However, the high cost of Ti alloys has so far inhibited their use. All this is changing, as scientists find ways to improve the strength of already existing Ti alloys. Researchers at Pacific Northwest National Laboratory went to work on a low-cost β-titanium alloy, Ti–1Al–8V–5Fe (Ti185), rearranging the alloy’s nano-structure by heat-treating and quenching it several times.

The result is an alloy that is 10-15% stronger than any Ti alloy currently on the market. We can expect other breakthroughs to occur, thanks to partnerships between Ti manufacturers and makers of autos or auto parts. Audi is already in partnership with German 3D printing company EOS, and a 3D printing centre is taking shape in the southern city of Ingolstadt. EOS is also partnering the British firm of GKN, which already has a partnership with Arcam.

This post is part of an article that was fully published in 3D fab+print magazine May/June. Read part 1 here and part 2 here. Don’t want to miss a thing? Subscribe to the 3D fab+print newsletter and receive new articles in your inbox weekly.