BLT launches high-strength aluminium and titanium alloys for Additive Manufacturing
July 18, 2024
Xi’an Bright Laser Technologies Co., Ltd (BLT), Xi’an, China, has introduced a new high-strength aluminium alloy for Laser Beam Powder Bed Fusion (PBF-LB) and a new titanium alloy for PBF-LB and Directed Energy Deposition (DED) Additive Manufacturing.
BLT-AlAM500 aluminium alloy
BLT’s new high-strength aluminium alloy, BLT-AlAM500, is specifically designed for aerospace applications. High-strength aluminium alloys are renowned for their strength, thermal stability, and superior processing performance, making them ideal for aircraft structural components and engine parts. Beyond aerospace, high-strength aluminium alloys are also essential in high-speed trains, lightweight automotive parts, and premium sports equipment.
At TCT Asia 2024, BLT showcased parts made from BLT-AlAM500, these included the bent tube, ventilation duct, and connecting pipe seen below.
These components, characterised by thin-walled, irregularly shaped tubular structures with internal cavities, demand high precision. Traditional manufacturing methods are complex, challenging, and costly. BLT optimised the design for Additive Manufacturing, and used its high-strength aluminium alloy and the company’s BLT-S400 metal PBF-LB machine, to produce the parts. Each component takes approximately thirty hours to form, and achieved an average weight reduction of around 20% compared to the original.
Post-heat treatment, the material achieves tensile strengths of 530-550 MPa, yield strengths of 480-500 MPa, and elongation rates of 11-17%. The material also boasts excellent fracture toughness and fatigue performance, with a room temperature fracture toughness of 30.8 MPa ·m1/2 and a high-cycle fatigue strength of 245 MPa (smooth sample) at room temperature. Compared to similar imported powders, the BLT-AlAM500 material is reported to offer a cost reduction of about 40-50%, significantly lowering manufacturing costs.
BLT-Ti65 titanium alloy
BLT’s new Ti65 is a multi-component, near-alpha high-temperature titanium alloy, said to maintain excellent strength, plasticity, creep resistance, and thermal stability at temperatures up to 650°C. This performance exceeds the limitations of traditional high-temperature titanium alloys, making Ti65 favoured in aerospace, chemical equipment, and marine engineering applications.
However, Additive Manufacturing Ti65 powder can result in defects such as unmelted or partially melted powder particles, inter-track and inter-layer porosity, and cracking, explains BLT. These can concentrate stress and increase the likelihood of material failure. These difficulties led BLT to develop and introduce its BLT-Ti65 powder.
The nominal chemical composition of BLT-Ti65 is Ti-5.9Al-4Sn-3.5Zr-0.3Mo-0.4Si-0.3Nb-2.0Ta-1.0W-0.05C, available in 15-53μm (for PBF-LB) and 75-180μm (for DED). Post-heat treatment, parts produced with 15-53μm BLT-Ti65 powder can achieve yield strengths of 483-503 MPa, tensile strengths of 604-624 MPa, and elongation rates of 16.5%-26.5% at 650°C. Parts produced with 75-180μm BLT-Ti65 powder can achieve yield strengths of 478-538 MPa, tensile strengths of 588-648 MPa, and elongation rates of 22%-32% at 650°C.
BLT’s material portfolio now includes over eighty types, including titanium alloys, high-temperature alloys, aluminium alloys, titanium-aluminium alloys, copper alloys, stainless steel, tool steel, high-strength steel, tantalum-tungsten alloys, silver, and hard alloys.
