Silicon Carbide Powder Exporter | High-Purity SiC Microgrits from China

Quick Answer

A dependable silicon carbide powder exporter delivers stable purity (typically 97–99.9% for black/green SiC), tight particle-size distributions aligned to FEPA/JIS/ANSI or micron ranges, and complete documents (TDS, SDS, COA, REACH/RoHS if applicable). When issuing an RFQ, specify grade (Black/Green), target PSD (e.g., D10/D50/D90 or mesh), standard (FEPA/JIS/ANSI or micron), application (lapping/polishing/refractory/ceramic), chemistry limits (SiC, free Si, SiO₂, Fe₂O₃), physical indices (bulk density, magnetic content, moisture/LOI), packaging (25 kg bags, 1 t jumbo), and Incoterms (FOB/CIF/DDP). Choose exporters with in-house screening/classification, PSA laser sizing, magnetic separation, acid wash capability, and proven export logistics to your port.

Table of Contents

• 1. What Is Silicon Carbide Powder?
• 2. Black vs. Green Grades & Typical Purity Windows
• 3. Standards & Sizing: FEPA / JIS / ANSI and Micron Series
• 4. Quality Control Checklist Exporters Should Meet
• 5. From Furnace to Container: Export Preparation Workflow
• 6. Application Mapping: How to Match Grade & PSD to Use Case
• 7. RFQ Template & Technical Data You Should Request
• 8. Price Drivers & Cost Optimization Tips
• 9. Logistics: Packaging, Pallets, Labels, Incoterms
• 10. Common Pitfalls & How to Avoid Supply Risk
• 11. Mini Case Study: Upgrading to Tight-PSD Microgrits
• 12. FAQ

1. What Is Silicon Carbide Powder?

Silicon carbide (SiC) is a covalent compound of silicon and carbon with outstanding hardness (≈9.3 Mohs), high thermal conductivity, chemical inertness, and strong abrasion resistance. When processed into powder (microgrits and microns), it becomes a precision material for lapping, polishing, advanced ceramics, ceramic coatings, and high-performance refractories. Exporter-grade SiC powder is produced by fusing high-quality raw materials in electric resistance furnaces, then crushing, shaping, magnetic cleaning, classification, and final packing under international grit or micron standards.

Two broad commercial families exist:

• Black SiC – Typically 97–99% SiC, tougher edges, widely used for grinding wheels, blasting, anti-wear refractories, and general lapping where removal rate matters.
• Green SiC – Usually 99–99.9% SiC with sharper, friable edges; preferred for fine lapping, precision polishing, and applications that value high purity and narrow PSD.

Because powder performance is governed as much by shape and distribution as by chemistry, serious buyers evaluate D10/D50/D90, particle shape factor, fines content, and magnetic residue—not just nominal “mesh”. A professional exporter will supply laser diffraction curves, sieve traces for macrogrits, and microscopy snapshots upon request.

2. Black vs. Green Grades & Typical Purity Windows

Choosing between black and green SiC depends on the target process window (cutting vs. finishing) and contamination tolerance. Below is a pragmatic view used by many exporters.

• Black SiC (Abrasive/Refractory Grades): SiC ~97–99%; common by-spec limits include Fe₂O₃ ≤ 0.2–0.4%, free Si ≤ 0.5–1.0%, free C per supplier spec. It offers higher toughness and economical cost for removal-oriented steps.
• Green SiC (High-Purity Microgrits): SiC 99–99.9%; stricter trace limits such as Fe₂O₃ ≤ 0.1–0.2%, free Si typically lower than black, and tighter control of ionic contamination. Selected where surface quality and contamination risk dominate.

Exporters typically hold multiple sub-grades by application: lapping/polishing (narrow PSD), refractory (optimized bulk density and reactivity), metallurgical (coarser, targeted chemistry), and coatings/ceramics (micro- and sub-micron fractions). Ask for a grade map that links supplier codes to your process needs.

3. Standards & Sizing: FEPA / JIS / ANSI and Micron Series

International buyers often specify grit by FEPA (Europe), JIS (Japan), or ANSI (US) conventions; for microgrits, micron ratings (e.g., 0.5–1 μm, 1–3 μm, 3–6 μm) are prevalent. A credible exporter can ship all three systems and provide cross-references. Important notes:

• FEPA F-grits – Common for bonded abrasives; e.g., F220, F400, F800, F1200. Each grade defines sieve/PSD envelopes.
• JIS – Popular for Japan-bound orders; be explicit whether you need JIS R 6001 mapping and how you accept tolerances.
• ANSI/CAMI – Used in some markets; exporters can usually cross-walk from FEPA with a tolerance disclosure.
• Micron Series – Define by D50 target and D90 cap. For example, 3–6 μm might be specified as D50=4.0±0.5 μm, D90 ≤ 7.5 μm, and fines (≤1 μm) ≤ 5%.

For dispute avoidance, request the exporter’s PSD certificate template and ensure it lists the instrument (e.g., Malvern or Sympatec), dispersant, ultrasonic setting, and refractive index used during measurement—these strongly influence results.

4. Quality Control Checklist Exporters Should Meet

Professional SiC powder exporters operate integrated lines and record batch-level data. Your technical audit should cover:

1. Chemistry – SiC %, Fe₂O₃, SiO₂, free Si, free C by XRF/ICP or supplier-recognized methods.
2. Particle Size Distribution – Sieve for macrogrits; PSA laser with multi-modal fitting for microgrits. Report D10, D50, D90, span, and fines.
3. Magnetic Content – Post-magnetic separation residue (ppm); important for precision polishing and ceramics.
4. Bulk & Tap Density – Determines flowability, packing, and slurry rheology; ensure spec windows per use case.
5. Moisture & LOI – Affects storage, slurry formulation, and shipping stability; define ≤0.2–0.5% per grade.
6. Cleanliness – Acid wash capability and post-wash neutralization; check ionic residue if relevant.
7. Visual/Shape Control – Optical/SEM snapshots for shape factor consistency.
8. Traceability – Unique lot IDs, retain samples, and COA linkage to shipment documents.
9. Compliance – SDS (GHS), REACH/RoHS if required, HS code accuracy, country of origin statements.

Exporters with ISO9001/14001 and documented SOPs tend to deliver lower batch-to-batch variation. Ask for their non-conformance procedure and typical response time for corrective actions.

5. From Furnace to Container: Export Preparation Workflow

Understanding how your powder is prepared helps you evaluate risk and lead time:

1. Fusion & Crystallization – Electric resistance furnace smelting; cooling into blocks/ingots.
2. Primary Crushing & Shaping – Jaw/roller mills to targeted bands, with controlled over-grind prevention.
3. Magnetic Separation & Cleaning – Multi-stage magnets; optional acid wash; rinse and dry to moisture spec.
4. Classification – Air classification and sieving (for macrogrits); micronization for microgrits; iterative tuning to hit D10/D50/D90.
5. QC Release – Chemistry + PSD + cleanliness; COA/analysis report is generated.
6. Packing – 25 kg paper/PE composite bags, or 500–1000 kg FIBCs (jumbo). Inner liner sealed; nitrogen purge optional for critical lines.
7. Palletizing – Heat-treated pallets (ISPM-15), stretch-wrap, corner boards, and top sheet; label with lot/batch, net weight, and handling icons.
8. Documentation – Commercial invoice, packing list, COA, SDS, HS code, certificate of origin (if needed), and booking with forwarder.

Lead time typically runs 7–15 days ex-works for standard microgrits, longer for custom PSD or washed grades. Plan buffer for port congestion and holidays.

6. Application Mapping: How to Match Grade & PSD to Use Case

Below is a practical mapping to speed up supplier discussions (guidelines—always pilot in your own process):

• Lapping & Polishing – Prefer Green SiC microgrits with narrow PSD (e.g., 0.5–1 μm, 1–3 μm, 3–6 μm). Specify D50 target, D90 cap, fines limit, magnetic residue, and ionic cleanliness if sensitive.
• Advanced Ceramics/Coatings – Black or green grades depending on purity threshold. Control moisture and agglomerates; consider silane or dispersant recommendations from exporter.
• Refractory Mixes – Black SiC powders blended with coarser fractions to boost thermal conductivity and erosion resistance. Focus on bulk density window and chemistry (SiC%, SiO₂, Fe₂O₃).
• Anti-Wear & Composite Fillers – Balance D50 for dispersion vs. surface finish; ensure low magnetic residue to protect tooling.

7. RFQ Template & Technical Data You Should Request

Sending a precise RFQ saves weeks. Copy/paste and fill in:

Subject: RFQ – Silicon Carbide Powder (Micron/FEPA), [Your Company]

1) Grade: [Black / Green]
2) Standard: [FEPA Fxxx / JIS #xxx / Micron 1–3 μm etc.]
3) Target PSD: [D10=?, D50=?, D90=?; fines ≤ ?%]
4) Chemistry: [SiC ≥ ?%; Fe2O3 ≤ ?%; SiO2 ≤ ?%; free Si ≤ ?%]
5) Physical: [Moisture ≤ ?%; Bulk Density ?–? g/cm³; Magnetic ≤ ? ppm]
6) Application: [Lapping/Polishing/Refractory/Ceramic/Coating; brief process]
7) Packaging: [25 kg bags / 1 t jumbo; pallets yes/no; inner liner yes/no]
8) Quantity & Delivery: [e.g., trial 1 t → monthly 10 t; target port + Incoterm]
9) Compliance & Docs: [SDS, COA each lot; REACH/RoHS? COO?]
10) Samples: [500 g / 1 kg with COA & PSD curve]

Please quote [FOB Qingdao] and [CIF (Your Port)] with lead time.

From the exporter, request: TDS, SDS, COA, PSD curve, sieve trace (if FEPA macrogrit), lot traceability statement, and packing photos. For recurring orders, ask for a control plan and annual review to discuss drift and improvements.

8. Price Drivers & Cost Optimization Tips

SiC powder pricing reflects furnace power cost, raw materials, yield, finishing steps, and logistics. Key levers:

• Grade & Purity – Green & washed microgrits cost more than black macrogrits. Only buy the purity you actually need.
• PSD Tightness – Narrower distributions imply higher classification time/yield loss—align your spec with process tolerance.
• Volume & Schedule – Consolidate shipments and set quarterly call-offs to lock better furnace allocation and freight.
• Incoterms & Route – Compare FOB + your own freight vs. CIF; sometimes exporter’s lane is cheaper due to contract rates.
• Packing Options – Jumbo bags reduce unit packing cost and handling, but ensure you can manage humidity and partial usage.

9. Logistics: Packaging, Pallets, Labels, Incoterms

Good exporters treat packaging as a quality attribute:

• Bags – 25 kg multi-wall paper/PE with inner liner; heat-sealed. Jumbo 500–1000 kg with food-grade liner for moisture-sensitive grades.
• Pallets – ISPM-15 heat-treated; typical 40 bags/pallet (1 t). Stretch-wrap + corner protectors + top sheet.
• Labels – Product name, grade/PSD, lot ID, net weight, handling icons, exporter info, and QR for COA download (if available).
• Incoterms – FOB (you control freight/insurance), CIF (exporter books to your port), DDP (rare but possible with agent networks).

For humid routes or long dwell times, request desiccant packs, moisture indicators, and pallet hoods. On receipt, log tare/gross weights and photograph seals before opening for traceability.

10. Common Pitfalls & How to Avoid Supply Risk

1. “Mesh-only” Specs – Always add PSD metrics (D10/D50/D90) and fines to avoid variability between lots/instruments.
2. Hidden Magnetic Residues – Insist on ppm reporting and a post-mag pass; tiny ferromagnetics can scratch critical surfaces.
3. Moisture Drift – Set limits and storage rules; define acceptance method (oven at 105 °C or Karl Fischer) to avoid disputes.
4. Document Gaps – Require SDS/COA/PSD with each lot; without them, customs and QA re-tests delay your line.
5. Over-specification – Tight specs raise cost; run DOE trials to learn the minimal viable PSD/purity for your yield.

11. Mini Case Study: Upgrading to Tight-PSD Microgrits

A polishing plant used a black SiC micron grade specified only as “3–6 μm.” Removal rate was good, but scratch rate and pad life varied. After switching to a green SiC grade with D50=4.0±0.4 μm, D90 ≤ 7.0 μm, ≤1 μm fines ≤ 5%, and magnetic ≤100 ppm, the client achieved a 22% defect reduction and 15% pad life increase. The exporter’s COA + PSD curve per lot made incoming QC fast and audit-proof. The unit price rose by 6%, but the total cost of ownership decreased by double digits due to yield and consumable savings.

12. FAQ

Q1: What purity should I choose for silicon carbide powder?

For lapping/polishing or high-spec ceramics, green SiC 99–99.9% is common. For refractory or general wear-resistant fillers, black SiC 97–99% typically suffices. Decide based on contamination sensitivity and surface finish targets.

Q2: Is FEPA grit the same as micron?

No. FEPA/JIS/ANSI define sieve and PSD envelopes for abrasive grits. Micron grades specify particle size directly in micrometers with D-value statistics. Ask your exporter for a cross-reference and the exact PSD curves.

Q3: Which documents are mandatory for importing SiC powder?

At minimum: Commercial Invoice, Packing List, SDS, COA/analysis, HS code, and if required a Certificate of Origin. Projects with environmental or electronics exposure may also ask for REACH/RoHS declarations.

Q4: How do I evaluate an exporter’s consistency?

Compare three consecutive COAs/PSD curves from different lots; check standard deviation of D50 and chemistry. Review their corrective-action records and whether they retain reference samples for 12 months.

Q5: What packaging is best for moisture-sensitive grades?

Use inner-lined 25 kg bags or FIBCs with sealed liners, desiccants, and pallet hoods. Define moisture limits and acceptance test methods in the PO.

Q6: Can exporters customize particle shapes?

Yes—within limits. Process choices (milling/classification) influence angularity and shape factor. Provide microscopy targets or surface finish outcomes so the exporter can tune classification.

Q7: What Incoterms should I choose?

FOB gives you freight control if you have negotiated rates; CIF is simpler when you prefer the exporter to handle sea booking and insurance. For urgent samples, EXW + courier is typical.

Q8: How much sample is needed to qualify a new grade?

For micron SiC, 500 g–2 kg is typical to run laboratory slurries and pilot cycles. Request the same COA/PSD package that accompanies bulk lots to ensure continuity.