Metal Binder Jetting (MBJ)
Full-density metal additive manufacturing — complex geometries, no support structures, high-throughput batch production for functional metal parts.
What Is Metal Binder Jetting?
Metal Binder Jetting (MBJ) is an additive manufacturing process in which a liquid binder is selectively deposited onto a bed of metal powder, layer by layer, to build a three-dimensional "green part." The part is then debound and sintered to near-full density — similar to the MIM process, but without the need for tooling or molds.
Unlike laser-based metal 3D printing (SLM/DMLS), binder jetting does not require support structures. The unsintered powder bed acts as natural support, enabling complex internal channels, overhangs and lattices that are impossible with any other manufacturing method.
Process Overview
- Powder Spreading: A thin layer (50–100μm) of metal powder is spread across the build platform using a roller or blade.
- Binder Deposition: Piezoelectric print heads selectively jet a liquid binder onto the powder bed, binding powder particles together in the cross-section of the part.
- Layer Repetition: The build platform lowers, a new powder layer is spread, and binder deposition repeats — building the part layer by layer from bottom to top.
- Depowdering: The build chamber is opened and loose powder is removed using compressed air and vacuum. The "green parts" are fragile but handleable. Unsintered powder is recycled for the next build.
- Debinding: Binder is removed via thermal or solvent processes, creating "brown parts."
- Sintering: Brown parts are fired in a controlled-atmosphere furnace at near-melting temperature, achieving 96–99.5% density.
- Secondary Operations: CNC machining, heat treatment, surface finishing — as required.
MBJ vs. MIM vs. SLM
| Feature | MBJ (Binder Jetting) | MIM | SLM/DMLS |
|---|---|---|---|
| Tooling Required | No | Yes (steel mold) | No |
| Support Structures | No (powder bed supports) | N/A | Yes (required) |
| Batch Production | Yes (full build volume) | Yes (multi-cavity mold) | Limited (build volume) |
| Surface Finish | Ra 3–6μm as-sintered | Ra 1.6μm as-sintered | Ra 6–10μm as-built |
| Density | 96–99.5% | 95–99% | 99.5–99.9% |
| Lead Time (prototype) | 3–5 days | 4–8 weeks (tooling) | 1–3 days |
| Lead Time (production) | 2–4 weeks | 2–4 weeks (after tooling) | 2–6 weeks |
| Cost per Part (volume) | Low–Medium | Lowest | High |
| Best For | Complex prototypes, medium-volume production, internal channels | High-volume production, simpler geometries | Dense prototypes, lattice structures, tooling inserts |
Available Materials
- Stainless Steel 316L: Corrosion resistance, medical and marine applications. Density ≥97%.
- Stainless Steel 17-4PH: Precipitation-hardening, high strength (up to 1,100 MPa after heat treatment). Aerospace and industrial.
- Tool Steel H13: Hot-work tool steel for molds, dies and high-temperature tooling. Hardness up to 52 HRC.
- Tungsten (W-Ni-Fe): High density (17+ g/cm³), radiation shielding, counterweights, balance weights.
- Inconel 625 / 718: Nickel superalloys for aerospace and high-temperature applications.
- Copper (Cu): High thermal conductivity for heat exchangers and electrical components.
Advantages
- No tooling: Go from CAD to metal parts in days — no mold design or fabrication delays
- No support structures: Complex internal channels, lattices and overhangs print without supports — saves material and post-processing time
- High throughput: Entire build volume can be packed with parts — hundreds of components per print job
- Material efficiency: Unused powder is recycled — 95%+ powder utilization rate
- Scalable: Ideal for bridge production (100–10,000 parts) between prototyping and MIM mass production
- Design freedom: Topology-optimized parts, conformal cooling channels, internal lattices — all printable
Typical Applications
- Tooling: Conformal cooling mold inserts — reduce cycle time by 30–70% compared to straight-drilled cooling
- Aerospace: Lightweight brackets, fuel system components, heat exchangers with internal channels
- Medical: Surgical guides, custom implants, instrument components in 316L and titanium
- Automotive: Prototype engine components, turbocharger housings, custom brackets
- Industrial: Custom impellers, valves, nozzles, pump housings with internal flow paths
Explore MBJ for Your Project
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