Siemens has made a significant breakthrough in the 3D printing of gas turbine blades, paving the way for manufacturers of power-generation and other heavy equipment to use additive manufacturing (AM) not only to fabricate models or prototypes, but also actual parts for their products.
The Munich, Germany-based company has full-load tested for the first time gas turbine blades made entirely through an AM process, according to Siemens.
Willi Meixner, CEO of Siemens Power and Gas Division, said the successful test—which was conducted the Siemens test center for industrial gas turbines in Lincoln, U.K., over several months—is a big step forward for using AM to fabricate power-generation equipment, “one of the most demanding areas of application for this technology.”
“Additive manufacturing is a major pillar in our digitization strategy,” he said, adding that the project team comprised Siemens engineers from Finspong, Lincoln, and Berlin, as well as engineers from Materials Solutions, a Siemens business that specializes in AM.
Gas turbines are combustion engines that produce electric current in the heart of a power plant. They convert natural gas or other liquid fuels to mechanical energy, which drives a generator that produces electrical energy.
|Siemens has successfully full-load tested a gas turbine blade that was for the first time entirely fabricated using additive manufacturing. The blades had to endure 13,000 revolutions per minute and temperatures beyond 1,250 degrees Celsius in the tests, conducted by an international team of Siemens engineers over several months. (Source: Siemens)|
The team installed the turbine blades—produced in an AM process from a high-temperature-resistant, powdered polycrystalline nickel-based super alloy—in a 13-megawatt SGT-400-type industrial gas turbine. They then subjected them to the usual extreme circumstances they would face in an operational environment, such as high pressures, extreme temperatures, and centrifugal forces that occur.
At full power, blades rotate at 1,600 kilometer per hour and carry loads of 11 tons. They also must withstand intense heat because they’re surrounded by gas with a temperature of 1,250 degrees Celsius when the turbine is in full operation.
Historically the process for producing blades that could withstand these conditions was either through casting or forging, requiring time-consuming and expensive processes. However, if these blades can be produced using AM, they will be far simpler and considerably less expensive to produce.
In the AM process, a laser beam is directed at layers of metal powder, which are heated and melted and then left to cool. This process is repeated layer by layer until the blade model from a 3D printer is complete. Using this process, the Siemens team produced a gas turbine blade from its design in two months versus two years, which is the time it usually takes, Meixner said.
“Using this technology, we can develop prototypes up to 90 percent faster,” he said. “We’re speeding up the development of new gas turbines with higher efficiency levels and increased availability and can thus deliver these improvements to our customers faster. The new flexibility in production allows us to more precisely tailor development to our customers’ requirements and deliver individual spare parts on demand.”
Elizabeth Montalbano is a freelance writer who has written about technology and culture for more than 15 years. She currently resides in a village on the southwest coast of Portugal.