Additive manufacturing is expected to revolutionize manufacturing across a wide range of industries. McKinsey & Co. calls the technique “a long-term game changer for manufacturers” and predicts the overall economic impact will reach $100 billion to $250 billion by 2025.
As additive manufacturing continues to develop, electron microscopy can help bring this methodology into the mainstream by offering manufacturers the quality control and materials characterization they need for their additive manufacturing processes. Today, metal represents the fastest-growing segment of the additive manufacturing industry, and electron microscopy is playing a key role.
So what exactly is additive manufacturing? Unlike traditional subtractive manufacturing, in which manufacturers gradually shave off pieces of a metal block to achieve a desired part, additive manufacturing involves joining together materials layer by layer. The process, also referred to as 3D printing, starts with computer-assisted design (CAD) software that creates a 3D model. Software is then used to break that model down into individual layers, and instructions for each layer are sent to a 3D printer. The 3D printer then builds the part by adding layers of metal powder, which are melted into a solid, integrated piece.
A new generation of manufacturing
Additive manufacturing allows manufacturers to build parts that are too complex using traditional methodologies. A great example is the inner channels of a fuel injector nozzle. The manufacturing method is also ideal when only a few parts are needed and it isn’t cost-effective to make a mold using traditional casting processes. In the case of medical implants, additive manufacturing is a true revolution as each implant can be exactly tailored to each patient’s specific body and needs.
As manufacturers turn to additive manufacturing to build metal objects, electron microscopy can help to improve their processes by making it possible to discover tiny defects that cause parts to corrode or break over time. Among the institutions that are using electron microscopy to advance additive manufacturing is the University of Connecticut, where they use electron microscopy to identify defects during the additive manufacturing process. By examining a test metal part using both a scanning electron microscope and a transmission electron microscope, for instance, researchers were able to trace the defect to impurities in the metal powder used in the 3D printer. This kind of multi-scale multi-modal imaging workflow is crucial to understand the fundamentals of how defects and microstructures form during printing.
Using a Thermo Fisher Explorer scanning electron microscope, researchers at the University of Connecticut were able to analyze the size and composition of metal powders.
With the help of electron microscopy, manufacturers can also develop heterogeneous metal objects with very precise characteristics. With traditional metallurgy, manufacturers typically start with a homogeneous block of metal, leading to a homogeneous final part. By contrast, additive manufacturing allows for the creation of heterogeneous parts using different metal powders to obtain the exact qualities desired, for example, a metal part that’s heat and corrosion-resistant near the edge, but highly durable in the middle. This innovative way of 3D printing is being developed, and it relies on electron microscopy to reveal the microstructures and interfaces between layers with different characteristics.
Electron microscopy also helps manufacturers optimize the microstructure of metal parts. Current metal processing standards such as heat treatments are based on traditional steel making. Parts built using additive manufacturing respond differently to these thermomechanical processes, and the microstructures and mechanical properties are different. Electron microscopy is crucial to understanding these microstructures and defining standards that are better adapted to 3D printing. Scanning electron microscopy with electron backscatter diffraction offers key insights into grain growth, while transmission electron microscopes reveal exactly how precipitations are formed in precipitation hardening 3D printed alloys..
Metal parts precisely tailored to specific needs
As additive manufacturing evolves, the technique is poised to change the manufacturing landscape. In the aerospace and automotive industries, for example, additive manufacturing is paving the way to more precise, lighter-weight parts that increase fuel efficiency and reduce carbon dioxide emissions. And in the medical device industry, the methodology is leading to surgical implants, dental crowns, and hearing aids that are more precisely tailored to the needs of individual patients.
A titanium 3D-printed limb designed by William Root
With the help of electron microscopy, researchers are rapidly improving additive manufacturing processes, leading to a new generation of metal parts that are safer, more durable, and more customizable than was previously possible.
To learn more about how Thermo Fisher and the University of Connecticut are partnering to advance additive manufacturing, watch the webinar.
Herman Lemmens, PhD, is a Business Development Manager, Industry at Thermo Fisher Scientific.