Aluminum Chromate Conversion (Chem Film / Alodine) Services
One-stop multi-axis CNC chromate conversion coating complying with MIL-DTL-5541, retaining conductivity & boosting paint adhesion for aerospace and electronic aluminum components
ISO 14001:2015 ISO 9001:2015 IATF 16949:2016
Aluminum Chromate Conversion Product Overview
CustomParts-MFG provides full-spec aluminum chromate conversion coating (widely known as Alodine or Chem Film), compliant with MIL-DTL-5541 (Type I/II, Class1A/3), AMS2473 & ASTM B449 standards, certified ISO9001, IATF16949, ISO14001. Our chemical conversion process grows ultra-thin protective film on aluminum substrate without cutting electrical conductivity, different from insulating anodizing finish. Available in RoHS-compliant trivalent Type II clear finish and military-grade hexavalent Type I golden coating, ideal as anti-corrosion barrier & pre-paint primer for aerospace, automotive, electronics and medical precision aluminum components.
The aluminum chromate conversion coating from your team provides exceptional corrosion resistance and consistent adhesion, which is critical for our precision assemblies. It has significantly improved both the durability and performance reliability of our products.
Core Functional Advantages of Chromate Conversion Coating
- Outstanding Anti-Corrosion Performance: Effectively block white rust & aluminum oxidation; Class1A finish passes up to 336hrs ASTM B117 neutral salt spray test.
- Preserve Electrical Conductivity: Keep low surface resistance＜5000μΩ/sq, perfect for EMI shielding, grounding and electronic contact components.
- Superior Paint/Powder Adhesion: Micro-porous crystal surface improves coating bonding, pass ASTM D3359 cross-hatch tape test without peeling.
- Negligible Dimensional Shift: Ultra-thin coating (0.00002 .0002 inch / 0.55μm), coating weight 10–50mg/ft², fully retain original tight machining tolerances.
- Dual Cosmetic Options: Uniform golden(Type I) or clear transparent(Type II) finish for part visual identification and classification.
Two Main Aluminum Chromate Conversion Types Standard
Type I Hexavalent Chromate (Golden/Yellow Finish)
High anti-corrosion Class1A spec, classic golden appearance, mainly specified for legacy aerospace & defense military projects requiring maximum rust protection.
Type II Trivalent Chromate (Clear Finish, RoHS/REACH Compliant)
Hex-free eco-friendly clear coating, meets global environmental regulations, mainstream choice for automotive, consumer electronics and general industrial parts.
Two Functional Classes for Both Types
- Class 1A: Max corrosion resistance & premium paint base for unpainted or top-coated parts
- Class3: Balanced anti-rust + low electrical resistance exclusively for conductive electronic assemblies
Aluminum Chromate Conversion Process
- Pre-Production DFM & Machining: Optimize design and masking, finish CNC machining per requirements.
- Surface Preparation: Degrease, rinse and deoxidize to eliminate oxides and contaminants.
- Chromate Treatment: Regulate bath parameters for uniform film and consistent color.
- Rinse & Drying: Clean with deionized water, then dry thoroughly.
- Quality Inspection: Test salt spray, coating weight, adhesion and conductivity in-house.
Aluminum Chromate Conversion Industry Application Segments
- Aerospace & Defense: Aircraft structural fittings, avionics chassis, satellite & missile MIL-spec hardware.
- Automotive & Motorsport: Engine brackets, transmission housings and aluminum castings for paint pretreatment.
- Electronics & Telecom: Heat sinks, chassis enclosures, waveguide components requiring stable conductivity & shielding.
- Medical Equipment: Sterilizable device housings & internal precision mechanical assemblies.
- General Industrial Machinery: Aluminum gears, valve bodies and pump fixtures against ambient corrosion.
One-Stop Chromate Conversion Integrated Service Superiority
- Full in-house chain: CNC machining → selective masking → chromate coating → post-treatment → final packaging; single PO unified management to eliminate cross-supplier delay.
- Flexible lead time: Standard order 2–5 working days; expedited rush processing available for urgent prototype projects.
- Optional auxiliary post-process: MoS2 dry film lubricant or custom topcoat directly after chromate treatment.
- Complete certification documents: Material & process COA, batch inspection report delivered per shipment.
Chromate Conversion Key Properties & Technical Specifications
- Corrosion Resistance: Salt spray resistance up to 336 hours (depending on type and alloy).
- Electrical Conductivity: Less than 5,000 micro-ohms per square inch (Maintains grounding/bonding).
- Coating Weight: 10–50 mg/ft² (Lightweight, does not affect tolerances).
- Heat Resistance: Withstands 200°F continuous service.
- Paint Adhesion: Meets ASTM D3359 (Cross-cut tape test) – Excellent base for powder coating or wet paint.
Request Free Custom Alodine Chromate Quotation
Upload STEP/IGES CAD drawings, aluminum grade & MIL/class specs via quote page, our surface engineering team provides free DFM analysis and detailed quotation within 24 working hours.
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FAQs About Aluminum Chromate Conversion
What is aluminum chromate conversion coating (Alodine/Chem Film)?
expand_less expand_moreA: Non-electrolytic chemical conversion treatment forming ultra-thin protective film on aluminum for anti-corrosion, paint primer and retained electrical conductivity.
Can chromate be processed for all aluminum alloy grades?
expand_less expand_moreA: Suitable for most common aluminum series; we conduct pre-sample testing for special alloy to confirm coating uniformity.
What is regular processing turnaround time?
expand_less expand_moreA: Standard batches take 2–5 business days after prep work; expedited service for urgent orders upon request.
What is the typical lead time for Chromate Conversion processing?
expand_less expand_moreA: Lead times vary based on part volume and complexity. For standard batches, processing typically takes 2–5 business days after surface preparation. We offer expedited services for urgent projects—contact us for a customized timeline.
Storage requirement for finished chromate parts?
expand_less expand_moreA: Store inside dry clean warehouse, avoid bare hand contact; VCI anti-rust packaging recommended for long-term inventory.
How long is salt spray service life of qualified coating?
expand_less expand_moreA: Class1A Type I up to 336hrs ASTM B117; Type II clear coating reaches minimum 96~168hrs salt spray resistance.
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