This production line is designed for semiconductor and high-temperature applications: graphite boats, graphite plates, trays and electronic-ceramic firing boards protected with a plasma-sprayed zirconia ceramic coating for vacuum and sintering furnaces. Using SX-80 plasma spraying equipment, Guangzhou Sanxin deposits yttria (Y₂O₃) and zirconia (ZrO₂) layers that raise heat and oxidation resistance and extend boat life substantially.
The Rough-Coating Problem and Our Fix
An overly coarse zirconia surface makes sintered products stick to the boat, deforming them and ruining sintering quality. Our process improvements:
- Raise yttria content in the zirconia powder for better phase stability at temperature.
- Finer powder cut – smaller ZrO₂ particle size deposits a denser, smoother lamella structure.
- Parameter tuning – higher plasma voltage with reduced current, lower powder feed rate and lower carrier-gas pressure let particles melt and atomise fully, raising surface finish.
- Finer blasting media – a finer silica grit before spraying gives a smoother base layer, and the coating that grows on it is smoother too.
Coating Properties
| Property | Value |
|---|---|
| Coating | Y₂O₃-stabilised ZrO₂, plasma sprayed |
| Service temperature | Up to 2000 °C |
| Thickness | 0.3–1.0 mm |
| Effect | No product sticking, longer boat campaigns |
The equipment is detailed on our SX-80 plasma spraying system page, and the coating-only option on graphite boat zirconia/yttria coating service.
Frequently Asked Questions
What changed in your process to keep the coating surface smooth?
Four measures: raising yttria content in the ZrO2 powder, switching to a finer powder cut, lowering feed rate and current while raising voltage so particles melt fully, and using a finer grit for pre-spray blasting so the base texture is smoother.
Can you develop the parameters for our own boat design?
Yes. Send us sample boats and material specifications; we run spray trials in our workshop and return a qualified parameter set with coating reports.
