Ceramic nozzles meter, direct or atomise a fluid, a gas or an abrasive stream. The orifice is the whole point of the part.
Zirconia nozzles suit applications where the tip takes knocks or is thermally cycled in use. The toughness protects an orifice edge that would chip on a more brittle material, which matters most on fine orifices.
Yttria-stabilised zirconia is the toughest of the engineering oxides, with 8-10 MPa·m½ fracture toughness and flexural strength to 1200 MPa. It absorbs the impact and side loads that would crack alumina, and it carries the lowest thermal conductivity of the structural ceramics here.
Two limits apply. Continuous service above roughly 800-1000°C destabilises the metastable tetragonal phase, and moisture between 200 and 300°C can trigger low-temperature degradation, so stabiliser grade is matched to the duty.
Specifications
| Orifice diameter | 0.1-10 mm |
| Orifice tolerance | ±0.005 mm |
| Outer diameter | 5-60 mm |
| Length | up to 150 mm |
| Orifice concentricity | 0.01 mm |
| Bore finish | Ra 0.4 µm |
| Entry | radiused, conical or sharp edge |
Zirconia Properties
| Composition | Yttria-stabilised zirconia (Y-TZP) |
| Density | 6.00-6.05 g/cm³ |
| Vickers hardness | 1200-1350 HV |
| Flexural strength | 900-1200 MPa |
| Fracture toughness | 8-10 MPa·m½ |
| Max. service temperature | 800-1000°C |
| Thermal conductivity | 2-3 W/m·K |
| Thermal expansion (20-1000°C) | 10.0 ×10⁻⁶/K |
Machining and Tolerances
Nozzles are turned and ground from solid stock rather than cast, because bore and outside have to be concentric. Orifices below about 0.5 mm are produced by precision drilling or laser, and the entry is radiused rather than sharp so the flow does not separate.
Where It Is Used
- Abrasive blasting and slurry spray nozzles
- Burner and plasma torch nozzles
- Atomising nozzles for coating and humidification
- Precision dispensing tips in fluid handling
- High-wear spray tips in scrubber and desulphurisation systems
Frequently Asked Questions
How small an orifice can you produce?
Down to about 0.1 mm depending on material and length. Small deep holes are the hardest features to hold, so we normally discuss the length-to-diameter ratio before quoting.
Which material wears longest in abrasive service?
Boron carbide then silicon carbide for pure abrasion, and silicon nitride where impact and thermal shock are present too. We match the material to the abrasive, the velocity and the fluid rather than defaulting to the hardest option.