3D printing is a set of additive manufacturing processes that creates physical objects from digital models one layer at a time. Unlike traditional manufacturing techniques (casting, drilling, machining, etc.), which tend to be subtractive in nature, 3D printing additively builds up an object instead of cutting it down from a larger block of material. While 3D printing dates back to the 1980s, the last decade has seen swift growth and excitement in the sector across the globe. As the various printing approaches improve and the materials palette grows, 3D printing is starting to move from just low volume, highly customized rapid prototyping applications to some final products and post-production customization.
Much of the excitement surrounding the additive manufacturing space is related to the potentially huge energy efficiency gains that this technology suite offers. The Department of Energy estimates that 3D printing can cut energy usage in manufacturing by 50% and reduce material usage by upwards of 90%! Additive manufacturing can eliminate numerous production steps, re-use manufacturing byproducts, and drastically simplify supply chains and transportation of goods.
Improved utilization of materials (significantly less waste generation) along with the removal of constraints associated with many traditional manufacturing techniques enables 3D printing to effectively create better, cleaner products that often are not possible otherwise. We are starting to see impacts in a variety of industries.
In the aerospace industry, where weight reduction is at a huge premium, 3D printed parts like porous metal foam cabin brackets save valuable kg’s. A 1 kg weight reduction in a commercial plane reduces fuel use, cuts CO2 emissions, and it has been estimated to save upwards of $3000/year. 3D printing is the only viable process to make and form these porous foam structures along with many engine components with complex internal structures. Even if a part can be made via traditional means, it often leads to excessive waste and higher costs. Some machined titanium components in aircrafts waste 90% of the solid billet they’re cut from and it can be difficult and energy intensive to reuse that wasted material.
In the medical field, 3D printing already is responsible for producing the majority of in-the-ear hearing aids. 3D printing is also being explored for patient-customized implants. Beyond the benefit of a hip or knee implant specifically designed to one’s unique body, 3D printing allows for the incorporation of porous surface features to improve implant biocompatibility and enhance bone growth.
Entirely new materials can also be fabricated with 3D printing. Some metals that cannot be traditionally alloyed due to their widely different chemical properties can be sintered together with a focused laser or electron beam. 3D printing can also assuage some thermal expansion mismatch concerns. While injection molding of multiple materials with substantially different thermal expansion properties is often infeasible, layers of these disparate materials can be built atop each other via 3D printing. Multifunctional materials are a final area where many are turning to 3D printing. Embedding additional functionality in structural elements – like embedded sensors or antennas in an airplane wing – could significantly reduce the total number of parts in a system.
While advances have been numerous over the last few years and the future looks bright, technical, economical, and regulatory hurdles remain. Improving printer throughput is a key factor in continued cost reduction. While it may never be economical to additively manufacture certain high volume products, cutting down the time to print a part opens up new doors. Also important here is lowering the currently large price premium between bulk material and its printing powder counterpart. Ethical quandaries like 3D printed guns and copyright violation will also have to be addressed moving forward. Hopefully, continued materials innovation in the 3D printing space will help usher in a manufacturing paradigm based on lowered energy consumption, less waste, and more customization for the end user – you!