Aerospace Hiwing develops high-temperature titanium alloy AM powder for China’s aerospace industry
December 10, 2020
Aerospace Hiwing (Harbin) Titanium Industrial Co., Ltd (AHTi), Harbin, Heilongjiang, China, a specialist in titanium material R&D and manufacturing, as well as the design, manufacturing and service of high-end titanium alloy products, has developed a high-temperature titanium alloy for use in Laser Beam Powder Bed Fusion (PBF-LB) Additive Manufacturing.
With the rapid expansion of the civil aerospace industry in China, the demand for specialised, high-temperature titanium alloys has become a critical challenge for key component development such as aerospace engines and spacecraft. In order to achieve optimised thrust–weight ratio, specialised titanium alloys are increasingly used in parts including engine compressor discs, blades, blisks, rotors, housing and intake pipes.
The need for weight reduction and high performance in these applications place higher demands on the operating temperatures of titanium alloys — other challenges in aerospace component development, including complex structures and faster development iterations, also challenge the established manufacturing process.
TA32 titanium alloy, with the composition Ti-5.5Al-3.5Sn-3Zr-1Mo-0.5Nb-0.7Ta-0.3Si, is a novel α-type high-temperature material developed in China. It offers high tolerance for operating temperatures of up to 550℃, and short-term tolerance up to 600℃, as well as good comprehensive mechanical properties such as tensile, fatigue and creep strength, making it an ideal alternative material for steel or nickel-base superalloy components.
AHTI, with its background in titanium material development and grounding in the aerospace industry, observed the emerging market for TA32 and the growth of metal AM as an ideal advanced manufacturing solution for high-temperature applications.
The company has been a customer of Farsoon Technologies, Changsha, Hunan, China, since 2018, when it invested in Farsoon’s PBF-LB machines at its facility for the engineering, process development and rapid prototyping of TA32 alloy components.
TA32 titanium alloy production uses an advanced cold crucible vacuum induction melting and air atomisation technology (VIGA-CC) to produce high-performance powders with high efficiency and a high yield of fine particles. After testing, the TA32 powder is said to offer excellent material properties such as high purity, high sphericity, high fluidity and high bulk density.
The physical properties of the material were also tested, revealing a 36 μm median particle size d50, a bulk density of 2.4 g/cm3 and a Hall flow rate of 45 s/50 g – all well suited for the PBF-LB process.
AHTi reportedly took advantage of the robust and open architecture of the Farsoon FS271M machine, including the ‘parameter-editor’ included in the company’s software, to accelerate its material processing development cycles with the development of customised TA32 processing parameters.
Using the parameter-editor, AHTi application engineers were also able to carry out a series of tests in which they controlled the laser energy density within the build chamber in order to determine the optimal processing parameters for producing TA32 parts.
Metallographic analysis of the TA32 parts produced in the Farsoon FS271M are said to show a fine crystal grain structure, without defects such as cracks or holes. The mechanical properties of the parts were further tested and shown to offer excellent tensile strength, flexibility and plasticity under high operation temperatures of 500℃, 550℃ and 600℃.