A number of companies cooperate to conduct titanium blade propeller testing

Recently, the University of Notre Dame Turbomachinery Laboratory (NDTL), Norwegian Titanium (Norsk Titanium), Pratt & Whitney (Pratt & Whitney) and TURBOCAM International Corporation announced the use of additive manufacturing technology for the production of integral titanium blade propellers Conduct further testing. The first test was completed in 2018, this test will detect the dynamic performance of the propeller. The product is produced using Norwegian Titanium Rapid Plasma DepositionTM (RPDTM) technology and will be certified in accordance with Pratt & Whitney ’s current quality certification standards for turbomachinery components. After the completion of this test, it can be proved that additive manufacturing can be applied to the field of turbomachinery, and it also paves the way for the completion of the entire product certification work.

The test will be conducted at the NDTL Turbo Machinery Test Center in Indiana, USA, which has the world's most advanced technology. After the first test, the product meets all design, speed and pressure ratio test points. This test focuses on observing the high and low cycle fatigue characteristics of the product. The test will include various acceleration and deceleration tests to observe the impact of real-time vibration on the blade.

Before the test, TURBOCAM International made a manufacturing quality assessment. No residual stress concentration was found in the evaluation. Stress concentration can cause deformation. In addition, TURBOCAM International also determined that the materials used in Norwegian Titanium's Rapid Plasma Deposition TM technology are also very suitable for use in traditional rolling mills, and its performance is comparable to Ti-6Al-4V forgings.

The final plan for the entire project is to establish specifications for the manufacture of complex, overloaded components for turbomachinery. At the same time, to achieve the goal of reducing manufacturing costs and production time. This goal has been achieved in the manufacture of Ti6Al4V fuselage components.

Pratt & Whitney will oversee the entire manufacturing and testing process to provide data support for further engine development in the future. A company spokesperson said that it was a pleasure to participate in this test. Using additive manufacturing technologies, such as Norwegian Titanium's Rapid Plasma Deposition TM technology, can shorten manufacturing steps and development time when manufacturing key turbomachinery components.

Compared with our common powder bed-based molten metal 3D printing technology, Norwegian Titanium's rapid plasma deposition TM technology is another metal 3D printing technology. According to the classification of ASTM, the rapid plasma deposition TM technology belongs to the directional energy deposition (DED) 3D printing technology. Allegedly, Bolite has many years of experience in 3D printing the entire leaf disk through its self-developed DED directional energy deposition technology (LENS coaxial powder feeding laser cladding 3D printing technology).

Additively manufactured components have been installed on aircraft for many years, but their role is mainly limited to non-critical components, such as piping systems and interior components. Even for engine components (such as the famous GE Leap engine fuel nozzle), the performance requirements for parts are mainly heat conduction rather than mechanical performance. For the overall blade disk, the challenge comes from both thermal conductivity and mechanical performance. It can be said that if the 3D printed overall blade disk can pass the layered aviation performance requirements test, this is indeed a milestone for the additive manufacturing industry.

However, for aircraft applications, how to obtain certification is an important challenge. Because the aircraft industry tends to certify the part design and insist on using the design throughout the aircraft's production life cycle. Pratt & Whitney's full participation has played a key role in promoting the certification of 3D printing.

In addition, in February 2019, SAE and Norwegian Titanium introduced standards for the application of directional energy deposition (DED) 3D printing technology. The two standards developed in collaboration are AMS7004 (a titanium alloy preform for Ti-6Al-4V stress relief plasma arc directed energy deposition additive manufacturing) and AMS7005 (wire feed plasma arc directed energy deposition additive manufacturing process). The new standard determines the minimum requirements for users of the aerospace industry to purchase Norwegian titanium rapid plasma deposition preforms. This has once again laid the foundation for the development of Norwegian Titanium in the aerospace field.

Norwegian Titanium obtained the first FAA airworthiness certification of 3D printed titanium alloy structural parts in February 2017. Its rapid plasma deposition technology has been applied to Boeing 787 Dreamliner series aircraft. It is said that the cost of parts can be reduced by 30%, and energy consumption, material waste and production cycle can be reduced.