Titanium, celebrated for its exceptional strength-to-weight ratio and resistance to corrosion, has long been a material of choice for demanding applications, particularly in aerospace. Traditionally, its high cost and complex processing limited its broader use. However, the advent of metal 3D printing, also known as additive manufacturing, is changing the landscape. This innovative technology is making titanium more accessible and economically viable across diverse sectors, including medical, automotive, and motorsports.
This article explores the unique attributes that make titanium an ideal material for 3D printing, the advanced technologies that facilitate its use, and the transformative applications that are emerging across industries.
The Indisputable Advantages of Titanium
| Sector | Properties | Applications |
|---|---|---|
| Aerospace | Corrosion resistance, High strength-to-weight ratio, High temperature resistance | Airframe and wing structures, Compressor blades, Rotors, Turbine engine components |
| Medical | Excellent strength, Biocompatibility (non-toxic, non-allergenic) | Orthopaedic devices: Spine, Hip, and Knee implants |
| Automotive & Motorsports | Corrosion resistance, High strength-to-weight ratio, High temperature resistance | Brake calipers, Brackets, Wheel rims, Uprights |
Titanium stands out due to its remarkable combination of properties. It possesses strength comparable to steel but at only 60% of its density. This exceptional strength-to-density ratio, coupled with excellent corrosion and chemical resistance, renders titanium highly desirable for high-performance sectors like aerospace and defense. In these fields, titanium alloys are crucial for creating lightweight components that maintain structural integrity even at elevated temperatures.
Furthermore, titanium’s biocompatibility is a key asset, making it perfectly suited for medical implants. Its non-toxic and non-allergenic nature ensures compatibility with the human body, critical for long-term implant success.
Despite these advantages, titanium has historically remained a costly material. This is primarily due to its relatively scarce abundance in the Earth’s crust and the energy-intensive and complex processes required to extract and refine it from its ores.
Why 3D Printing and Titanium are a Perfect Match
Titanium presents significant machining challenges due to its low thermal conductivity. During conventional machining processes like CNC milling, heat tends to concentrate on the cutting tool rather than dissipating into the material. This localized heat build-up can lead to rapid tool wear and reduced efficiency.
Moreover, subtractive manufacturing methods like machining inherently generate substantial material waste. Given titanium’s high cost, this waste becomes a significant economic concern.
Metal 3D printing emerges as an efficient alternative. It minimizes material waste by precisely building parts layer by layer, using only the necessary material. The most prevalent titanium alloy for 3D printing is Ti6Al4V (Titanium 6Aluminium 4Vanadium), renowned for its excellent mechanical properties and printability. Pure titanium is also used in specific applications within 3D printing.
The Compelling Benefits of 3D Printing with Titanium
Metal 3D printing offers significant advantages in material efficiency and design flexibility, particularly for titanium components.
3D printing titanium unlocks a range of benefits, especially in industries striving for efficiency and performance. In aerospace, the concept of the “buy-to-fly ratio” is crucial. It signifies the ratio of raw material purchased to the weight of the final part. Traditional manufacturing of titanium aerospace components can result in buy-to-fly ratios as high as 25:1, implying that for every kilogram of finished part, up to 25 kilograms of raw material are needed, with the excess being machined away.
Titanium 3D printing drastically reduces this ratio to between 3:1 and 12:1. This is because additive manufacturing processes deposit material precisely where needed, minimizing waste to primarily support structures. For a costly material like titanium, this reduction in material waste translates directly into substantial cost savings.
Furthermore, 3D printing facilitates the creation of topologically optimized designs. Topology optimization is a design technique that uses algorithms to remove material from areas of a part that are not structurally critical, based on specified loads and constraints. This results in lightweight components without compromising strength or stiffness. These complex, optimized geometries are often only achievable through additive manufacturing. The aerospace sector particularly benefits from this, as lighter components lead to improved fuel efficiency and performance in aircraft.
Technologies Powering Titanium 3D Printing
Three primary metal 3D printing technologies are employed for titanium: Direct Energy Deposition (DED), Electron Beam Melting (EBM), and Selective Laser Melting (SLM).
Direct Energy Deposition (DED)
DED technology, pioneered for titanium 3D printing in 1997 by Aeromet Corporation for aerospace applications, uses a focused energy source, such as a laser or electron beam, to melt titanium powder or wire as it is deposited layer by layer. DED’s key advantage is its ability to produce large-scale parts with high deposition rates, reaching up to 320 cubic centimeters per hour. Variations of DED include Sciaky’s Electron Beam Additive Manufacturing (EBAM) and Wire Arc Additive Manufacturing (WAAM).
Electron Beam Melting (EBM)
Developed by the Swedish company Arcam (now part of GE Additive), EBM technology utilizes an electron beam in a vacuum environment to melt and fuse titanium powder layers. EBM is known for its higher accuracy compared to DED and is well-suited for intricate, smaller parts. The vacuum environment and high process temperature in EBM minimize residual stresses in printed parts, often eliminating the need for post-print heat treatment. Arcam’s Q10 and Q20 machines, and the advanced Spectra H, are specifically designed for titanium 3D printing, targeting medical implants and aerospace components, including those made from challenging titanium aluminide alloys.
Selective Laser Melting (SLM)
Similar to EBM, Selective Laser Melting (SLM) is a powder bed fusion technology. However, SLM uses a laser beam instead of an electron beam to melt and fuse titanium powder. SLM offers the highest precision among these three technologies, with layer thicknesses as fine as 20 microns. This accuracy makes SLM ideal for parts requiring fine details and complex geometries.
Diverse Applications of Titanium 3D Printing Across Industries
While aerospace remains the dominant sector for titanium 3D printing, industries like medical, motorsports, chemical, and marine are increasingly adopting this technology to manufacture high-performance titanium components.
Aerospace
A 3D-printed and machined titanium part showcases the capabilities of additive manufacturing in creating complex aerospace components.
In aerospace, titanium 3D printing is instrumental in reducing the weight of critical structural components, especially in jet engines, gas turbines, and airframe structures. Leading aerospace manufacturers are integrating 3D-printed titanium parts into their aircraft.
Liebherr-Aerospace & Transportation SAS, a major aerospace supplier, has begun serial production of 3D-printed titanium nose landing gear brackets for the Airbus A350 XWB. These are the first Airbus parts made from 3D-printed titanium, demonstrating the technology’s maturity for critical applications. The use of titanium 3D printing reduced the weight of these brackets by 29% while increasing their stiffness.
Boeing, in partnership with Norsk Titanium, is utilizing titanium 3D printing to produce large structural titanium components for the 787 Dreamliner. Norsk Titanium’s proprietary Rapid Plasma Deposition (RPD) technology, a DED-based process using titanium wire and plasma torches, is FAA-qualified for producing these parts. RPD is reported to be significantly faster and more material-efficient than powder-based systems and traditional forging, potentially saving Boeing millions of dollars per aircraft.
Currently, titanium 3D printing in aerospace is primarily focused on smaller components. However, its use is expected to expand to larger structural parts as the technology advances and cost efficiencies are further realized.
Medical
Titanium’s biocompatibility, strength, and corrosion resistance make it highly attractive for medical implants, particularly orthopaedic and dental devices. 3D printing enables the creation of implants with intricate, porous structures that mimic natural bone. These porous scaffolds encourage bone cell ingrowth and promote faster, more effective osseointegration (bone fusion).
Osseus Fusion Systems is a pioneering company in this field. Their Aries-L Interbody Fusion Devices, 3D-printed titanium spinal implants, feature a proprietary multi-axis mesh and optimized micro-surface topology to enhance bone fusion rates. Osseus manufactures these complex devices on FDA-validated SLM 3D printers.
The medical applications of 3D-printed titanium are rapidly growing. By 2020, it was estimated that medical uses would account for approximately 274,000 kg of titanium, indicating a strong positive trajectory for titanium 3D printing in the medical industry.
Automotive & Motorsports
Bugatti’s 3D-printed titanium brake caliper demonstrates the potential of titanium 3D printing in high-performance automotive applications.
While the broader automotive industry is more cost-sensitive, high-performance sectors like racing and luxury vehicles are embracing titanium 3D printing for its performance advantages.
Bugatti famously developed a 3D-printed titanium brake caliper for its Chiron supercar. This critical component, measuring 41 x 21 x 13.6 cm, was 3D printed in 45 hours using SLM technology. The resulting caliper is about 40% lighter than an equivalent aluminum part and meets stringent strength, stiffness, and temperature requirements. Bugatti also utilizes titanium 3D printing for active spoiler brackets, achieving significant weight reductions and rigidity improvements.
HRE Wheels, a US-based wheel rim manufacturer, is leveraging EBM technology to 3D print complex-shaped titanium wheel rims. This approach significantly reduces material waste compared to traditional manufacturing methods, achieving a weight reduction of 19% and decreasing material waste from up to 80% to just 5%.
In motorsports, titanium 3D printing plays a “critical strategic role” in producing lighter, high-performance vehicles. The Oxford Brookes Formula Student team, in collaboration with the UK’s Manufacturing Technology Centre (MTC), redesigned and 3D-printed titanium uprights for their race car using EBM, achieving a remarkable 50% weight saving.
Addressing the Challenges of Titanium 3D Printing
Despite its numerous benefits, titanium 3D printing faces ongoing challenges. Standardization is a key area. The industry needs robust standards to ensure the quality and reliability of titanium parts produced by additive manufacturing. Boeing and Oerlikon entered a five-year partnership in 2018 to focus on standardizing titanium 3D printing processes and ensuring printed components meet stringent FAA and DoD requirements.
The high cost of titanium powder is another significant hurdle. Titanium powder optimized for 3D printing can range from $300 to $600 per kilogram. Innovative powder production methods are being developed to reduce costs. PyroGenesis, a Canadian company, utilizes its NexGen™ Plasma Atomization System to produce titanium powder at higher rates (over 25 kg/h), aiming to lower prices through increased production efficiency. Metalysis, a UK-based company, has developed an electrolysis-based method to transform titanium oxide into titanium powder, offering a potentially more eco-friendly and cost-effective alternative to traditional methods. Metalysis began commercial production of titanium powders in 2018 and is scaling up to deliver significant quantities annually.
SmarTech Analysis predicts that advancements in titanium powder manufacturing could reduce the average price of titanium by 17% by 2024, further enhancing the economic viability of titanium 3D printing.
Titanium 3D Printing: A Powerful Manufacturing Solution
Titanium 3D printing has firmly established itself as a valuable manufacturing technology in aerospace, medical, and automotive industries. The combination of titanium’s superior material properties and 3D printing’s capabilities for design complexity, lightweighting, and waste reduction creates a compelling value proposition.
As titanium powder costs decrease and application knowledge expands, titanium 3D printing is poised to become an even more widespread and transformative manufacturing alternative across an expanding array of industries.
