Mold finish standards
Published on Monday, 09. February 2015
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Content Guide：Select surface treatment processes based on mold material, application, and cost requirements
Mold Surface Treatment Standards (2025 Update)
Select surface treatment processes based on mold material, application, and cost requirements:
Process | Applicable Materials | Surface Hardness (HV) | Wear Resistance Improvement | Cost (CNY/cm²) | International Standards |
|---|---|---|---|---|---|
Nitriding | Tool Steel (H13, SKD61) | 800-1200 | 2-3x | 0.8-1.5 | ISO 2639:2025 |
Hard Chrome Plating | Carbon Steel, Stainless Steel | 900-1100 | 1.5-2x | 2-4 | ASTM B650-2025 |
PVD Coating | Mold Steel, Carbide | 2000-3500 | 4-8x | 5-12 | ISO 20523:2025 |
Laser Cladding | High-Wear Area Repair | 600-1500 | 3-5x | 15-30 | ASTM F3056-2025 |
Sandblasting + Passivation | Aluminum/Zinc Alloys | Ra ≤0.4 μm | Corrosion Resistance Enhanced | 0.3-0.8 | ISO 8503-2:2025 |
Nitriding:
Case Depth: 0.1-0.3 mm (Temperature: 500-550°C)
Limitation: Not suitable for mold steel with copper content >0.5%
PVD Coating (TiAlN/DLC):
Coating Thickness: 2-5 μm, Temperature Resistance ≤800°C
Pre-Polishing Required: Ra ≤0.2 μm
Hard Chrome Plating:
Plating Thickness: 10-50 μm, Hydrogen Embrittlement Risk (Post-Treatment: 200°C/4h Dehydrogenation)
Compliance: Meets EU RoHS 2025 hexavalent chromium limits
Avoid Failure-Prone Features:
Sharp Internal Corners: Fillet radius ≥0.3 mm (prevents coating delamination)
Deep Grooves/Fine Holes: Width/Diameter ≥1 mm (ensures coating uniformity)
Lifespan Enhancement Strategies:
High-Wear Areas: Local Laser Cladding + Nano-Composite Coating (lifespan increase 300%)
Cooling Channels: Electrolytic Polishing (Ra ≤0.8 μm, reduces scale buildup)
Smart Self-Healing Coating:
Microcapsule Slow-Release Technology: Repairs scratches ≤20 μm depth
Temperature Range: -30°C~250°C (compliant with ISO 21714:2025)
Cryogenic Plasma Sulfurizing:
Friction Coefficient Reduced to 0.02-0.05 (ideal for precision injection molds)
Processing Time: 30-60 mins, Cost: ¥6-10 CNY/cm²
Grade | Surface Roughness (Ra) | Hardness (HV) | Applications |
|---|---|---|---|
Precision Grade (Class A) | ≤0.1 μm | ≥2000 | Optical lens molds, microstructured molds |
General Grade (Class B) | ≤0.4 μm | ≥1000 | Automotive parts, connector molds |
Economy Grade (Class C) | ≤1.6 μm | ≥800 | Packaging molds, low-complexity molds |
Notes:
Custom solutions (e.g., acid-resistant or anti-stick coatings) require hybrid treatments (e.g., CrN+PTFE composite coatings);
All processes must comply with ISO 9001:2025 quality control certification.
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