When repairing metal makes it even better

(From left) ARTC technical director Nicholas Yeo, CEO David Low and strategic development and collaboration director David Butler at the centre which developed the laser metal deposition process.
(From left) ARTC technical director Nicholas Yeo, CEO David Low and strategic development and collaboration director David Butler at the centre which developed the laser metal deposition process. PHOTO: LIM YONG TECK FOR THE STRAITS TIMES

Nowadays, when your fridge or television set breaks down, you invariably hear the refrain: "Just buy a new one."

Imagine having to do that whenever some part of an aircraft engine, made of a special alloy and costing tens of thousands of dollars, sustains minor damage. Trashing a large chunk of high-grade metal because of a few dents does not seem the way to go.

Instead, fixing it is what the Advanced Remanufacturing and Technology Centre (ARTC), an institute of the Agency for Science, Technology and Research, is doing using new and advanced technology. Said Dr David Low, the centre's chief executive: "The repair process is an opportunity to make it even better."

The Straits Times met Dr Low and his colleagues at ARTC last week in the run-up to the Singapore Airshow, to catch a glimpse of heavy metal being rehabilitated.

The secret is in a process called laser metal deposition, which uses a powerful and highly precise laser to melt the damaged area on the engine component while injecting new metal powder into the mix, creating a very strong bond between old and new. Both damaged old components and new ones with manufacturing defects can potentially be treated in this way.

Dr Low said that using newer generations of wear-resistant material for the repair makes the component even stronger than before, yet it would probably cost no more than using the original material.

Instrumental in ARTC's ability to develop cutting-edge technology such as this is its operating model of private-public partnership, in this case with a broad consortium of 35 member companies including Rolls-Royce, Siemens, 3M and Zeiss, and a close partnership with Nanyang Technological University.

Although this model is used by several institutions in the United States and Britain, it is unique in Asia, said Dr Low.

"It's like a country club - you have to join and pay a membership fee," he added, explaining that those who sign up are committed for the long term and more open in sharing ideas.

It helps that Singapore is ranked top in Asia and fourth in the world for intellectual property protection in the World Economic Forum's Global Competitiveness Report 2015/2016. Dr Low said: "This is definitely one of the reasons companies are willing to conduct cutting-edge R&D in Singapore."

Mr Nicholas Yeo, technical director of ARTC, said: "We focus on technology that is maturing but needs a little more investment to reach the stage where Singapore can derive commercial value."

Remanufacturing technologies developed at ARTC go on to be used in aircraft engine overhaul and repair facilities in Singapore, such as the Singapore Aero Engine Services, a joint venture between three big industry players in the Asia-Pacific: SIA Engineering, Hong Kong Aero Engine Services and Rolls-Royce.

Engine companies such as Rolls-Royce "sell by the hour", said Dr Low.

Remanufacturing makes a lot of sense, especially for high-value aircraft parts. On average, remanufacturing a generic component saves energy, materials and water by 60 to 90 per cent, reduces pollution by more than 80 per cent, and is 50 to 70 per cent cheaper than getting a new component, said ARTC.

"When you remanufacture an aircraft component, you actually circulate it back into the economy," said Mr Yeo, bringing in the concept of the circular economy, an ideal scenario of zero waste and zero pollution.

Of course, there is a limit as to how many times a component can be remanufactured, and this is determined by mathematical modelling and mechanical tests, said Dr Low. "Then they put a safety factor on it," he added.

Asked about the future of ARTC, Dr Low conjured up a sophisticated network of interconnected, automated and self-correcting machines that make remanufacturing processes much more efficient and less error-prone. "We must continue to climb up the value chain, where we have smart processes and systems that can do difficult and complex repairs."

If this can be achieved for jet engines, maybe it can be done for fridges and television sets, too.

Lin Yangchen

A version of this article appeared in the print edition of The Straits Times on February 15, 2016, with the headline 'When repairing metal makes it even better'. Print Edition | Subscribe