In product design and manufacturing, speed and flexibility are key. But working with metal often means slow setups, high costs, and long lead times. Metal Binder Jetting offers a solution. It changes how engineers and manufacturers approach metal part production by making it faster, more flexible, and more affordable.
This method is gaining popularity in the aerospace, automotive, and medical industries. Let’s examine how it works and why more companies are using it.
What is Metal Binder Jetting?
O jato de ligante metálico é um processo de fabrico aditivo. Começa com uma fina camada de pó metálico espalhada por uma plataforma de construção. Uma cabeça de impressão move-se sobre a superfície e deposita um aglutinante líquido em áreas selecionadas. Este aglutinante mantém o pó unido. De seguida, é adicionada outra camada de pó e o processo repete-se.
The machine builds the part layer by layer. When finished, the part is called a “green part.” It’s soft and fragile. The part then goes through drying and sintering. Sintering involves heating the metal in a furnace until it fuses. The result is a dense, solid metal part.
This method doesn’t use lasers or melting. So, it’s faster and works at room temperature during printing. That reduces stress on the part and increases the machine’s speed.
How Does Metal Binder Jetting Work?
Metal binder jetting builds parts layer by layer using powdered metal and a binding agent. Here’s the step-by-step breakdown:
File Preparation and Slicing
The process begins with a 3D model created in CAD software. This model is exported as an STL file. The file is then sliced into thin layers using special software. Each slice represents one layer that the printer will build.
The software also sets essential printing parameters, including:
- Layer thickness: Commonly set between 50–100 microns, impacting the detail and surface finish.
- Binder saturation: Usually 50–70% saturation, controlling how much binder is used per layer.
- Build orientation: Selected carefully to minimize shrinkage and distortion after sintering.
These settings are crucial because metal binder jetting typically results in 15–20% shrinkage during sintering. Proper planning helps achieve high accuracy in the final product.
Once slicing is finished, the file is sent to the printer.
Layering and Binder Application
A thin layer of fine metal powder is spread evenly across the build platform inside the binder jetting printer. A recoater blade or roller carefully smooths this powder layer to ensure uniform thickness.
Next, an inkjet print head moves across the powder bed, spraying tiny droplets of liquid binder exactly where the part is designed. This binder slightly hardens as it dries, bonding the powder particles in that specific layer shape.
The build platform then lowers by one layer height, usually around 50–100 microns. A fresh layer of metal powder is spread, and the binder application repeats. This continues layer by layer until the entire part is formed.
Curing and Post-Processing
Immediately after printing, the resulting object, called a “green part,” is still delicate and porous. It may contain around 40–50% binder material by volume at this stage. Careful handling is critical to avoid damage.
The first step after printing is curing. The part is heated gently, usually around 150–200°C, for a few hours to fully evaporate any residual moisture and harden the binder.
Next is debinding, where most binder material is removed to prepare for sintering. Debinding typically involves heating the part to around 400–600°C, or using a chemical solvent to dissolve the binder.
Finally, the part undergoes sintering, a high-temperature step in which it is heated close to—but below—the metal’s melting point, often between 1100°C and 1400°C, depending on the metal alloy used. During sintering, metal particles fuse, significantly increasing density.
After sintering, the part gains strength similar to conventionally manufactured components, reaching ultimate tensile strengths from 600 MPa up to 1000 MPa for materials like stainless steel or nickel alloys.
Materials Used in Metal Binder Jetting
The choice of materials affects part strength, finish, and cost. Metal Binder Jetting works with several types of metal powders. The most common ones include:
- Aço inoxidável (such as 316L and 17-4 PH): Good for corrosion resistance and strength.
- Aços para ferramentas: Used for wear-resistant parts like cutting tools and molds.
- Inconel: A nickel alloy used in high-heat or harsh environments.
- Cobre: Chosen for its high electrical and thermal conductivity.
- Titânio: Lightweight and strong, used in aerospace and medical parts.
Design Guidelines for Metal Binder Jetting
Designing for Binder Jetting is different from traditional machining or casting. Parts need to account for shrinkage, powder flow, and post-processing.
Tolerances and Wall Thickness Recommendations
Printed parts often shrink during sintering. Shrinkage rates range from 15% to 20%. Designers must scale the CAD model to match the final part size after shrinkage.
- Minimum wall thickness: Around 1 mm for most metals. Thinner walls may break during debinding or sintering.
- Tolerance range: ±0.2 mm is typical after sintering. Higher accuracy may need secondary machining.
Features like small holes or threads may need post-processing to reach tight tolerances or smooth finishes.
Support Structures and Shrinkage Compensation
One significant advantage of Binder Jetting is that it doesn’t need support structures during printing. The surrounding powder acts as a natural support. This allows more design freedom compared to processes like SLM or DMLS.
However, parts may deform during sintering due to uneven shrinkage or gravity. So, sintering supports—different from printing supports—are sometimes needed. They are added during post-processing to help the part hold its shape in the furnace.
Shrinkage compensation is built into the software. Still, complex shapes may shrink unevenly. Designers should avoid sharp internal corners or unsupported long spans.
Tips for Design Optimization
- Keep wall thickness consistent to reduce warping.
- Use fillets instead of sharp edges to avoid stress points.
- Avoid large flat surfaces, which may warp or curl during sintering.
- Hollow out thick areas to lower weight and speed up sintering.
- Add escape holes for trapped powder in enclosed cavities.
Advantages of Metal Binder Jetting
Metal binder jetting brings several benefits to production. It saves time, reduces waste, and works well for complex designs.
High-Speed Production for Complex Parts
Binder jetting prints faster than most impressão 3D em metal methods. It spreads powder and binds each layer in seconds, and there is no need to melt the metal, making the process much quicker than laser-based printing.
The speed helps shorten lead times. It’s ideal for making multiple parts at once. You can fill the entire build area with parts and print them together. This is helpful when you need small to medium batches of metal parts.
Lower Material Waste Compared to Subtractive Methods
Traditional machining cuts metal from a solid block, creating a lot of scrap. Binder jetting builds parts layer by layer, using only the powder needed for the part.
Unused powder stays in the build box. You can collect and reuse it, lowering material costs and waste. It also reduces the need for recycling or disposal steps.
No Need for Support Structures During Printing
Most 3D metal printing processes need supports. These are extra structures that hold the part while it prints. Removing them takes additional time and can damage the part.
Binder jetting prints without supports. The loose powder around each part provides enough backing, making the process smoother. You can design freely without worrying about how to support overhangs.
Desafios e Limitações
While binder jetting offers speed and flexibility, it comes with some trade-offs. These challenges affect strength, accuracy, and safety.
Part Strength and Density Issues
Parts made with binder jetting are not as dense as those produced by machining or metal injection molding. After sintering, some small gaps may remain inside the part. These gaps reduce strength.
This can limit the use of binder jetting in structural or high-load applications. Post-processing or using a denser method may be preferred for parts that require high durability.
Dimensional Accuracy and Shrinkage Control
Binder jetting parts shrink during sintering. The shrinkage happens because the binder burns off and the metal fuses.
Controlling this shrinkage is tricky. If the settings are off, the final part can end up slightly smaller or misshapen. You need to account for shrinkage during the design and printing stages.
Binder Safety and Handling Requirements
The binder contains chemicals. Some can be flammable or hazardous if not handled properly. Proper ventilation is needed during printing and curing.
Operators must wear protective gear and follow storage and waste handling rules to avoid fire or health hazards.
Aplicações em todos os sectores
Metal binder jetting is used in many industries. It helps make complex metal parts quickly and at lower costs.
Aerospace Components and Lightweight Structures
Weight reduction is a top priority in aerospace. Binder jetting can create hollow or lattice-filled parts that reduce weight without losing strength.
It also supports fast prototyping of colchetes, caixas, and mounts. This helps engineers test designs before full production. The ability to print several parts in one build speeds up development cycles.
Automotive Prototyping and Customization
During the design phase, car makers use binder jetting to build engine parts, brackets, and heat shields. It allows for testing shapes and fits without waiting for tooling.
It also supports custom parts for limited-run or luxury vehicles. You can change the design quickly and print on demand. This flexibility saves cost and time compared to machining.
Medical Tools and Implants
Binder jetting supports small-batch production of custom implants and surgical tools. Since each patient is different, custom-fit parts are valuable.
Doctors and engineers can create shapes that match patient anatomy. The process handles complex geometries, such as internal channels for fluid flow or lightweight mesh structures.
Industrial Jigs, Fixtures, and End-Use Parts
In factories, binder jetting helps produce tools, jigs, and fixtures. These parts help guide, hold, or position components during manufacturing.
Binder jetting is a fast option when you need a strong part with a special shape. It also works well for spare parts and low-volume metal components.
Conclusão
Metal binder jetting is a fast and flexible way to make complex metal parts. It prints with metal powder and binder and uses sintering to finish the part. This process helps reduce waste, speed up production, and avoid support structures. It works well for custom parts, small batches, and detailed designs.
Are you interested in exploring metal binder jetting for your next project? Our team can help you choose the proper process and turn your design into a high-quality metal part. Contacte-nos hoje to discuss your requirements and get a fast quote.
Olá, chamo-me Kevin Lee
Nos últimos 10 anos, tenho estado imerso em várias formas de fabrico de chapas metálicas, partilhando aqui ideias interessantes a partir das minhas experiências em diversas oficinas.
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Kevin Lee
Tenho mais de dez anos de experiência profissional no fabrico de chapas metálicas, especializando-me em corte a laser, dobragem, soldadura e técnicas de tratamento de superfícies. Como Diretor Técnico da Shengen, estou empenhado em resolver desafios complexos de fabrico e em promover a inovação e a qualidade em cada projeto.
