Key Takeaways

• Start your PVD coating RFQ with precise details about the substrate and heat treatment.
• Document the incoming surface condition thoroughly to avoid RFQ mistakes.
• Define measurable acceptance criteria to ensure successful coating performance.
• Involve quality and regulatory functions early in the process for controlled uses.
• Provide clear drawings that mark critical, coated, and masked surfaces.

Physical vapour deposition is a process family

The Society of Vacuum Coaters describes vacuum coating as depositing films in a sub-atmospheric environment and identifies PVD as material originating from a vaporized solid or liquid surface. PVD includes different source and plasma approaches; the acronym alone does not specify one coating, chemistry or performance.

Coating choice interacts with substrate material, heat treatment, surface finish, geometry, temperature limits, loading and environment. A successful coating on one part does not prove the same result on a similar-looking part.

Sputtek publishes a PVD coating overview. It confirms a public topic and inquiry route, not acceptance of a particular substrate, geometry, regulated use, tolerance, process, certification, price, lead time or result.

Step 1 defines the required function and failure mode

Describe what the part does and what problem is being investigated. Is the concern adhesive wear, abrasion, galling, corrosion, material pickup, release, friction, appearance, electrical behaviour or another measurable issue? State where the problem occurs and under which operating stage.

Avoid vague goals such as “last longer.” Record the present baseline: material, process, service duration or cycle definition, inspection method and observed failure. If the baseline cannot be measured, a claimed improvement will also be difficult to verify.

Identify safety and regulatory consequences. A decorative component, forming tool, medical device and nuclear part require different evidence and controls. Stop and involve responsible quality and regulatory functions before the supplier proposes a coating for a controlled use.

Step 2 identifies the substrate and metallurgical state

Provide the exact material designation, grade, supplier certificate where applicable, heat treatment, hardness evidence if controlled, prior coatings, brazing or welding, and any case-hardened or nitrided layer. “Steel,” “carbide” or “aluminum” is not a complete substrate definition.

Note maximum temperature or distortion limits and how they were established. Do not ask a supplier to infer heat-treatment history from appearance. If the material is unknown, consider material verification before coating engineering begins.

SVC’s thin-film troubleshooting education notes that not every film can be deposited on every substrate and identifies substrate surfaces, contamination and preparation as important variables. That supports a stop gate when identity or condition is uncertain.

Step 3 documents the incoming surface condition

Record manufacturing steps such as machining, grinding, polishing, EDM, heat treatment and prior service. State the measured roughness method and location if surface finish is functional. Photograph representative surfaces and defects with scale and part identification.

Identify oils, coolants, residues, oxidation, corrosion, embedded media and temporary preservatives. Do not clean a regulated or precision component with an unapproved method merely to make it look ready. Ask the coating supplier what incoming state and packaging are required.

Separate pre-existing defects from coating acceptance. Nicks, pits, cracks, burrs and edge damage can affect fixturing, cleaning and the final surface; create an incoming inspection record and disposition rule.

Step 4 marks critical, coated and masked surfaces

Provide a controlled drawing or marked model. Use clear identifiers for surfaces that require coating, must remain uncoated, can tolerate overspray or transition, and may be used for fixturing or electrical contact. Avoid relying on an informal photograph alone.

State dimensional tolerances before and after coating, fits, threads, sealing surfaces, cutting edges, radii and areas where thickness affects assembly. The coating supplier must confirm what transition and coverage are achievable for the process and geometry.

Identify handling restrictions and cosmetic surfaces separately from functional ones. A visible colour variation may not establish thickness, chemistry or performance, and a consistent colour does not replace inspection.

Step 5 describes operating loads and environment

Record contact materials, lubrication, speed, pressure, temperature range, duty cycle, atmosphere, cleaning chemicals, sterilization, food or pharmaceutical contact, corrosion exposure and maintenance. Use measured or controlled values where available and label estimates.

Describe the complete system, not only the failed part. A counterface, misalignment, lubricant, debris or thermal condition can dominate performance. PVD is not a substitute for fixing an unresolved design or process cause.

Tell the supplier which environmental or material restrictions apply. Do not assume a generic coating name meets a customer specification, regulatory rule or prohibited-substance requirement.

Step 6 turns the need into measurable acceptance criteria

Choose tests that relate to the function and are practical for the part. For example, if the part is used in a high-wear application, consider wear resistance tests such as ASTM G65 or ASTM G77. If corrosion resistance is critical, refer to standards like ASTM B117 for salt spray testing. Establishing these criteria early on will help in assessing the coating’s performance post-application.

Document the acceptance criteria clearly, including acceptable ranges for each test, to ensure that both the coating supplier and the customer have a mutual understanding of the expectations.

Step 7 plans trials and samples

Coordinate with the coating supplier to determine the best approach for trials and samples. This may involve producing a small batch of parts to evaluate the coating’s performance before full-scale production. Ensure that the trial plan includes the same parameters as the final production run to yield relevant results.

Step 8 defines volume and logistics

Clearly specify the expected production volume and any logistics considerations. This includes lead times, shipping methods, and any special handling requirements for the coated parts. Providing this information upfront can help the coating supplier plan effectively and avoid delays.

Step 9 completes technical review

Before finalizing the RFQ, conduct a thorough technical review with all stakeholders involved. This ensures that everyone is aligned on the requirements and expectations, reducing the risk of miscommunication and errors during the coating process.

Avoid RFQ mistakes

Common mistakes in the RFQ process include vague descriptions, incomplete documentation, and failure to involve necessary stakeholders. By following the steps outlined above, you can minimize these risks and improve the chances of a successful coating application.

Frequently asked questions

For more information about PVD coating and the RFQ process, consider visiting the Society of Vacuum Coaters for additional resources and guidance.

Request a technical quote review

If you need assistance with preparing your RFQ or have specific questions about PVD coating, feel free to contact us for a technical quote review.

Sources & References

• Society of Vacuum Coaters – What is Vacuum Coating?
• SVC Thin-Film Troubleshooting Education
• ASTM G65 – Standard Test Method for Measuring Abrasion Using the Dry Sand/Rubber Wheel Apparatus
• ASTM G77 – Standard Test Method for Measuring the Wear Resistance of Materials to Sliding Abrasion
• ASTM B117 – Standard Practice for Operating Salt Spray (Fog) Apparatus