Custom Coating provides hexavalent chromium-free conversion coating and surface treatment services for applicable aluminum components requiring specification-focused surface preparation and production support.
Hexavalent chromium-free conversion coatings are used where customer, industry, environmental, or specification requirements call for alternatives to conversion coating processes containing hexavalent chromium.
Depending on the applicable process and specification, these conversion coatings can help support corrosion resistance, coating adhesion, and surface preparation for subsequent finishing operations.
Custom Coating reviews component material, applicable specifications, customer requirements, and production needs before processing begins to help determine the appropriate surface treatment approach.
Why Use Hexavalent Chromium-Free Conversion Coatings?
Hexavalent chromium-free conversion coatings may be specified when a component requires surface treatment without the use of conversion coating compositions containing hexavalent chromium.
Depending on the applicable process and requirements, these coatings may support corrosion protection and provide a suitable surface for subsequent paint, powder coat, adhesive, or other finishing operations. ASTM B921 specifically describes non-hexavalent chromium conversion coatings for aluminum as being used for corrosion protection and as a base for organic films, including paints, plastics, and adhesives.
Hexavalent chromium-free conversion coating requirements may involve:
- Customer specifications
- Environmental requirements
- Applicable industry standards
- Corrosion protection requirements
- Paint and coating adhesion
- Surface preparation needs
- Component material considerations
- Production requirements
- Testing and documentation needs
The appropriate conversion coating process depends on the component material, applicable specification, intended application, and subsequent finishing requirements.
Understanding Hexavalent Chromium-Free Conversion Coatings
Non-Hexavalent Chemistry
Hexavalent chromium-free conversion coatings are formulated without hexavalent chromium and may be used where applicable specifications or requirements call for alternative surface treatment approaches.
Surface Preparation
Conversion coatings create a chemically treated surface that can support subsequent finishing operations, including paint, powder coating, adhesives, and other specified coatings.
Application Requirements
The appropriate process depends on the aluminum substrate, component condition, performance requirements, applicable specifications, and intended use.
Trivalent and Other Non-Hexavalent Conversion Coating Options
Not all hexavalent chromium-free conversion coatings use the same chemistry. Depending on the applicable specification and approved process, alternatives may include trivalent chromium-based conversion coatings or other non-hexavalent surface treatment technologies.
For example, MIL-DTL-5541 identifies Type II conversion coatings as compositions containing no hexavalent chromium, while ASTM B921 addresses non-hexavalent chromium conversion coatings for aluminum and aluminum alloys.
Processing considerations may include:
- Applicable specification requirements
- Approved process chemistry
- Aluminum substrate material
- Corrosion resistance requirements
- Subsequent coating or bonding requirements
- Electrical performance requirements where applicable
- Customer-specific requirements
- Production processing needs
- Testing and documentation requirements
Custom Coating reviews applicable specifications and customer requirements to help determine the appropriate conversion coating approach for each project.
Understanding Hexavalent Chromium-Free Requirements
Hexavalent chromium-free conversion coating requirements can vary depending on component material, applicable specification, intended application, and subsequent finishing requirements.
Before production begins, Custom Coating reviews available customer and production information to help determine the appropriate processing approach.
Requirements may include:
- Customer drawings and specifications
- Applicable material requirements
- Component material review
- Surface condition considerations
- Conversion coating requirements
- Subsequent finishing needs
- Testing and inspection requirements
- Documentation and traceability needs
- Production processing requirements
By reviewing requirements before production, our team can help support consistent processing for applicable aluminum components.
Where Hexavalent Chromium-Free Conversion Coatings Are Used
Hexavalent chromium-free conversion coatings are commonly used on aluminum and aluminum alloy components where corrosion protection, paint adhesion, and customer or OEM requirements must be addressed without the use of hexavalent chromium.
These coatings may be used for:
- Aluminum components requiring corrosion protection
- Components that will receive subsequent painting or powder coating
- Applications with customer or OEM requirements for hexavalent chromium-free processing
- Components manufactured to applicable military, automotive, or industry specifications
- Applications where surface preparation and conversion coating are part of a larger finishing system
Applications for Hexavalent Chromium-Free Conversion Coatings
Hexavalent chromium-free conversion coatings may be used on applicable aluminum components requiring corrosion protection, surface preparation, or a suitable base for subsequent coatings and finishing operations.
- Aluminum housings
- Panels and enclosures
- Fabricated aluminum parts
- Machined aluminum components
- Cast aluminum components
- Industrial equipment parts
- Components prepared for paint
- Components prepared for powder coat
- Other customer-specified aluminum parts
Surface Treatment Without Hexavalent Chromium
Hexavalent chromium-free conversion coatings provide an alternative surface treatment approach for applicable aluminum components.
Depending on the specified process and application, conversion coatings can support corrosion resistance and provide a suitable surface for subsequent paint, powder coating, adhesive bonding, or other finishing operations.
Processing considerations may include:
- Applicable specifications
- Aluminum substrate material
- Corrosion protection requirements
- Subsequent finishing operations
- Customer and environmental requirements
Custom Coating reviews component and production requirements to help determine the appropriate surface treatment approach.
Need Chrome-Free Conversion Coating for Aluminum?
Custom Coating provides chrome-free conversion coating services for aluminum and aluminum alloy components, supporting applicable customer, OEM, and military specifications. Our team can review your component requirements, drawings, specifications, and production needs to help determine the appropriate processing approach.
Related Conversion Coating Services
Hexavalent Chromium-Free Conversion Coating FAQs
A hexavalent chromium-free conversion coating is a surface treatment process that does not use conversion coating compositions containing hexavalent chromium. Depending on the applicable chemistry and specification, these processes may support corrosion protection and subsequent finishing operations.
Trivalent chromium conversion coatings do not use hexavalent chromium. However, “hexavalent chromium-free” is a broader category, and not every hexavalent chromium-free conversion coating necessarily uses trivalent chromium.
MIL-DTL-5541 identifies Type I conversion coatings as compositions containing hexavalent chromium and Type II conversion coatings as compositions containing no hexavalent chromium.
Depending on the applicable process and requirements, conversion coatings may provide a suitable surface for subsequent paint and other organic coatings. The appropriate process should be selected based on the component material, coating system, and applicable specifications.
Yes, applicable conversion coating processes may be used to prepare aluminum surfaces before powder coating. The appropriate pretreatment depends on the aluminum material, component condition, powder coating system, and applicable requirements.
Depending on the applicable conversion coating process and specification, these treatments may support corrosion protection requirements. The required performance should always be reviewed against the applicable specification and intended use.
Providing the following information helps Custom Coating review your project:
- Component drawings
- Aluminum material
- Applicable specifications
- Required quantities
- Subsequent finishing requirements
- Production requirements
Need Hexavalent Chromium-Free Conversion Coating?
Contact Custom Coating to discuss your aluminum components, applicable specifications, surface treatment requirements, and production needs. Our team can review your project and help determine the appropriate processing approach.