What Is Powder Bed Fusion?
Dec 15th 2022
Powder bed fusion (PBF) is one of the most popular types of additive manufacturing today. This method involves creating a 3D digital model that is dissected into several different layers, each layer is then melted on the power bed with a heat source. Let’s have a look at what makes this such a common choice for manufacturers, and a few things that you should look out for if you’re considering powder bed fusion for your 3D printer.
Types of Powder Bed Fusion
Keep in mind that there are many different types of PBF. This process calls for applying a concentrated heat source to a powdered material in order to sinter it together. This heat source is usually a laser, but it can also be done with an electron beam. This process can be divided into:
- Selective Laser Sintering (SLS): Originally pioneered in the 1980s, this technique still enjoys enduring popularity due to its reliability. A laser is used to sinter powdered polymer materials in layers here. The final product generally requires light post processing with a brush, and some shrinkage can also occur.
- Direct Metal Laser Sintering (DMLS): Also known as selective laser melting, 3D printers use this form of powder bed fusion almost exclusively for metal powders. Powders are fully melted by a laser in a process that produces an immense amount of structural stress, and therefore can require additional support structures. DMLS is well known for its ability to produce highly resilient final products.
- Electron Beam Melting (EBM): Electrons are rapidly shot at the powder bed under controlled conditions to disperse the powder in layers. The bed is constantly heated from start to finish in this process, and some post processing such as a light finish might be required afterwards.
Other than these three, there are also other powder bed fusion methods used for specialized applications — usually just a slight variation on the same basic principle. Picking the best metal powder and PBF method in a given scenario is a question of knowing what your final product demands. DMLS tends to be the right call for durable prints that require some flexibility, while EBM is commonly used for its ability to produce thin metal sheets and other niche applications.
Why Should You Use Powder Bed Fusion For 3D Printing?
The reason it’s so easy to find powder bed fusion in nearly every industry is that it’s considered a jack of all trades. PBF is incredibly efficient in terms of both quality and value, particularly for manufacturers working with polymer materials. Since support structures are generally not needed for polymer and post-processing is light, products can be printed en masse and with minimal error.
Mass production aside, this process is also well-suited for prototyping and even creating industry-grade components used in other machinery. Increasingly affordable polymer and metal powders, such as aluminum alloys, have enabled businesses of all sizes to produce highly durable parts. DMLS, in particular, is widely used to create metal prototypes that boast a superior level of finish and detail.
The Cons of Powder Bed Fusion
Businesses choosing powder bed fusion for 3D printing will have to make a trade-off between speed and versatility. PBF might be great for a range of different materials, but post-processing can take time when working with, say, a complex fuel injection system printed with titanium powder. Other more expensive processes like vat polymerization are far faster than powder bed fusion.
Other cons depend entirely on the materials used in the print. Manufacturers working with polymer can experience a certain amount of thermal warping and will have to design around it. Producers working with metal powders should account for support structures that have to be cut out after the print. Support isn’t always necessary, but it can prevent distortion for metal products.
Surge Ahead With 3D Printing
Aerospace, healthcare, or high-volume industrial manufacturing, powder bed fusion is a great choice for 3D printing, no matter the market you’re operating in. KBM helps businesses make the shift to efficient additive manufacturing with a digital marketplace featuring high quality and authentic materials for a seamless experience. Get the metal powders your business needs today.