Processes - Additive Manufacturing
Metal Binder Jetting (MBJ)
Metal Binder Jetting (MBJ) was developed in the early 1990s at MIT and later commercialized by companies like ExOne and Digital Metal. These early innovators expanded the technology's capabilities from printing simple sand molds to functional metal components. Over time, MBJ has evolved into a widely used industrial process due to its scalability and compatibility with a variety of materials.
Metal Binder Jetting is a powder-based additive manufacturing method. It involves spreading thin layers of metal powder over a build platform and selectively depositing a liquid binding agent using inkjet printheads. This creates a "green" part that holds its shape but is not yet fully dense or strong. The green part is then cured, de-powdered, and typically sintered in a furnace to fuse the metal particles together. The process allows for the creation of complex geometries without the need for support structures, as the surrounding powder acts as a natural support during printing.
Unlike laser-based metal printing methods (such as SLM or DMLS), MBJ does not use heat during the printing phase. This eliminates thermal stresses and warping, enabling the production of large parts and batch production with high throughput. However, post-processing steps like sintering can result in shrinkage, which must be accounted for during design.
Advantages
Cost-Effectiveness
Binder Jetting is a highly economical additive manufacturing process, capable of producing metal parts and full-color prototypes at significantly lower costs. It is also more energy-efficient and affordable compared to laser-based methods such as Direct Metal Laser Sintering (DMLS) or Selective Laser Melting (SLM), as well as Material Jetting technologies.
Large Build Capacity
Binder Jetting enables the production of large and complex metal parts without being constrained by thermal stresses or warping, making it ideal for intricate geometries. Binder Jetting enables the production of large and complex metal parts without being constrained by thermal stresses or warping, making it ideal for intricate geometries.
Suitable for Low to Medium Volume Production
The process is well-suited for small to medium batch manufacturing due to the relatively low material costs and efficient powder usage. The process is well-suited for small to medium batch manufacturing due to the relatively low material costs and efficient powder usage.
Efficient Powder Utilization
The unbound powder naturally supports printed parts during fabrication, reducing the need for additional support structures. Furthermore, any unused powder can be recycled for future builds, minimizing material waste. The unbound powder naturally supports printed parts during fabrication, reducing the need for additional support structures. Furthermore, any unused powder can be recycled for future builds, minimizing material waste.
Disadvantages
Mechanical Properties
Metal Binder Jetting parts have lower mechanical properties than DMLS parts, due to their higher porosity. Metal Binder Jetting parts have lower mechanical properties than DMLS parts, due to their higher porosity.
Surface finishing and resolution
Only rough details can be printed with Binder Jetting, as the parts are very brittle in their green state and may fracture during post processing. Beyond that it Offers moderate resolution. It generally does not come close to the high detail achievable with technologies like material-jetting or stereolithography. Only rough details can be printed with Binder Jetting, as the parts are very brittle in their green state and may fracture during post processing. Beyond that it Offers moderate resolution. It generally does not come close to the high detail achievable with technologies like material-jetting or stereolithography.
Capabilities
Disclaimer: All process specifications reflect the approximate range of a process's capabilities and should be viewed only as a guide. Actual capabilities are dependent upon the manufacturer, equipment, material, and part requirements.