August 29, 2024 by SME Communications The additive manufacturing (AM) landscape is rapidly evolving, thanks largely to the significant advancements in materials research and development. Our latest Additive Manufacturing Coffee Chat was facilitated by Christie Hasbrouck, a Research and Development Engineer at Penn State University. We were joined by colleagues in the field, including: Dr. Jennifer Fielding, SME Fellow and Chief of Ceramics Branch at the Air Force Research Laboratory Amy Alexander, Mechanical Development & Applied Computational Engineering Unit Head at the Mayo Clinic Their discussion, expertly guided by Christie, highlighted some of the most groundbreaking innovations that are shaping the future of AM, making it more versatile and impactful across various sectors. Exploring the Potential of Metal in AM Amy highlighted the transformative impact of powder bed fusion technologies, including both laser-based and electron beam methods, on the capabilities of different metals in AM. This technology has broadened the horizon for medical applications, with titanium (specifically TI64) being a popular choice for implants due to its strength and biocompatibility. However, the exploration doesn’t stop at titanium. There is a growing interest in using other metals, like cobalt chrome and stainless steel for surgical tools and instrumentation. The advancements in metal AM in medicine are not just limited to creating implants. They extend to pre-surgical planning and the production of accurate anatomical models. These models allow surgeons to practice procedures and create surgical guides, effectively bridging the gap between virtual planning and real-world execution. Companies are leveraging metal AM to produce exact replicas of anatomical structures, enhancing surgical precision and outcomes. Pioneering New Frontiers in Polymers and Composites Jennifer discussed her team’s efforts with thermosets, particularly polyimide materials capable of frontal polymerization. This innovative approach involves triggering a chemical reaction during printing, which rapidly propagates and locks in the material’s cross-links, enhancing the final product’s properties. Continuous carbon fiber printing has also seen significant developments in recent years. This technology is now capable of producing large structures such as small aircrafts and satellites. The ability to achieve properties comparable to conventional polymer matrix composites while adding geometric complexity and agility to large-scale structures is a game-changer for the aerospace and defense industries. The advancements in ceramics are equally promising. With an increasing number of ceramic printers available, there is potential for larger and more complex builds, The goal is to fine-tune the material properties, such as reducing porosity, to achieve better quality prints straight from the printer. Scalability and Cost-Effectiveness of Advanced AM Materials When it comes to scaling these advanced materials for mass production, there are unique challenges and opportunities. Amy emphasized that her institution focuses on producing tools and devices for surgical applications and patient specific cases, rather than mass production. Their prints are typically limited to 20-25 parts, highlighting the importance of consistency, reliability, and reproducibility. For example, in proton beam therapy for cancer treatment, precision in printed bolus helmets is crucial. Amy and her team must ensure that these helmets meet stringent specifications, such as material characteristics and layer adhesion, to ensure effective treatment with minimal exposure to non-target tissues. Jennifer discussed the challenges of scaling materials for Department of Defense (DoD) applications, which hinge on rigorous qualification processes. A case in point is the thermoplastic material Ultem 9085, which required extensive statistical analysis and collaboration with research institutes and OEM’s to develop a qualification framework. This framework ensured that materials produced on different machines exhibited consistent properties, reducing variability and enhancing reliability. A primary obstacle to scalability in AM is the need for continuous human monitoring, especially with larger robotic additive machines. The reliance on human oversight limits the ability to fully embrace the benefits of AM. The path forward involves accumulating more data and understanding the variability to reach a point where the process and be trusted and automated. Conclusion The advancements in materials research and development are propelling additive manufacturing into new realms of possibility. From groundbreaking applications in medicine to innovative approaches in polymers, composites, and ceramics, the future of AM is bright. While scalability and cost-effectiveness pose challenges, ongoing research and collaboration continue to push the boundaries, making AM a versatile and indispensable tool across various industries.
