Monoclinic Zirconia Powder — Unstabilized ZrO₂ for Refractories, Foundry & Thermal Processing
SEMITECH Monoclinic Zirconia is an unstabilized ZrO₂ powder (≥99.0% ZrO₂+HfO₂, mp 2715°C, thermal conductivity 2.0–2.5 W/m·K) for refractory linings, investment casting, thermal barrier bond coats, ceramic pigments, and abrasives. Available in fused (d50 10–45 μm) and precipitated (d50 ~1 μm) grades.
Technical Specifications — Fused Grade
| Parameter | Unit | Typical Value | Test Method |
|---|---|---|---|
| ZrO₂ + HfO₂ | wt% | ≥99.0 | XRF |
| HfO₂ | wt% | ≤2.0 | XRF |
| SiO₂ | wt% | ≤0.15 | ICP-OES |
| Fe₂O₃ | wt% | ≤0.05 | ICP-OES |
| TiO₂ | wt% | ≤0.10 | ICP-OES |
| Al₂O₃ | wt% | ≤0.10 | ICP-OES |
| Na₂O | wt% | ≤0.05 | ICP-OES |
| Crystal phase | — | Monoclinic ≥95% | XRD |
| Melting point | °C | 2715 | — |
| Density (theoretical) | g/cm³ | 5.68 | — |
| Particle size d50 | μm | 10–45 (adjustable) | Laser diffraction |
| Particle size d90 | μm | ≤100 | Laser diffraction |
| Color | — | White to off-white | Visual |
Technical Specifications — Precipitated Grade
| Parameter | Unit | Typical Value | Test Method |
|---|---|---|---|
| ZrO₂ + HfO₂ | wt% | ≥99.5 | XRF |
| HfO₂ | wt% | ≤2.0 | XRF |
| SiO₂ | wt% | ≤0.05 | ICP-OES |
| Fe₂O₃ | wt% | ≤0.02 | ICP-OES |
| Na₂O | wt% | ≤0.10 | ICP-OES |
| Cl⁻ | ppm | ≤500 | Ion chromatography |
| Loss on ignition (1000°C) | wt% | ≤1.5 | Gravimetric |
| BET surface area | m²/g | 5–25 | N₂ adsorption (ISO 9277) |
| Particle size d50 | μm | 0.5–5.0 (adjustable) | Laser diffraction |
| Crystal phase | — | Monoclinic ≥90% | XRD |
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Application Suggestions
Refractory Linings and Furnace Furniture
Zirconia crucibles, nozzles, and linings for glass melting and steel continuous casting. Fused grade with SiO₂ ≤0.15 wt% meets glass-contact purity requirements.
Investment Casting Shell Systems
Face-coat material for aerospace superalloy castings (turbine blades). Chemically inert to molten Ni-based superalloys at 1500–1600°C, superior to alumina and silica face coats. Meets AMS 2175.
Thermal Barrier Coating Bond Coats
Plasma-spray feedstock (d50 15–45 μm, spheroidized) for APS bond coat deposition in gas turbine TBC systems.
Ceramic Pigment Synthesis
Precipitated grade (d50 1–3 μm, BET 10–20 m²/g) serves as host lattice for zircon blue, coral, and praseodymium yellow pigments at 900–1200°C firing.
Abrasive and Polishing Applications
Fused monoclinic zirconia (Mohs 6.5) for coated abrasives and grinding wheels — superior grain integrity vs. alumina on heat-sensitive materials.
Technical Support & FAQ: Monoclinic Zirconia Powder
+Q1: What is the difference between fused and precipitated monoclinic zirconia?
Fused: electric-arc melted and crushed, dense angular particles, low surface area — for refractories, abrasives, thermal spray. Precipitated: chemical precipitation from ZrOCl₂, fine high-surface-area powder — for pigments, catalysts, reactive applications.
+Q2: Why not use stabilized zirconia for refractories?
Yttria-stabilized costs 3–5x more and is unnecessary for most refractories. The monoclinic-to-tetragonal volume change is managed through controlled heating rates and composite formulation.
+Q3: What purity is needed for glass-contact refractories?
SiO₂ ≤0.15 wt%, Fe₂O₃ ≤0.05 wt%. Low-impurity variant (SiO₂ ≤0.05%) available at MOQ 500 kg for specialty glass.
+Q4: What are pricing, MOQ, and lead times?
Fused: MOQ 500 kg, 7–14 days. Precipitated: MOQ 25 kg, 10–21 days. Free 1 kg samples with COA. Contact info@semitechnm.com.
Packing & Storage Information
Fused: 25 kg PP bags or 1000 kg FIBC. Precipitated: 25 kg kraft bags or 500 kg FIBC; vacuum-sealed for high-BET grades. Store dry; fused grade has unlimited shelf life; precipitated 18 months sealed at <60% RH.