Dongguan Xintai Metal Surface Treatment Co., Ltd. · Electrocoating (CED/AED) specialist Sales: +86 181 2376 0267 | Request a quote

Case Studies

The cases below are grouped by industry and process type. Customer names and part numbers are anonymised under NDA; only the process approach and the reasoning behind it are shown.

OUR CLIENTS

Industries we serve

Our customers come from consumer electronics, automotive electronics, drones, AI hardware and cross-border hardware programmes, including several industry leaders and their tier-1 and tier-2 suppliers (names withheld under NDA).

Consumer electronics

Black e-coat for MIM precision parts, stainless steel stampings and CNC-machined aluminum: typically folding-screen hinges, SIM trays, camera brackets and EMI shields.

MIM partsStainless steelMatte black

Automotive electronics

Motor cores, sensor housings and connector shells where salt spray resistance and electrical insulation are explicit requirements.

Silicon steelSST≥48hInsulation ≥ 10 MΩ

Drones and smart devices

Gimbal brackets, airframe structures and folding hinges — lightweight metal parts where appearance consistency and weather resistance both matter.

Die-cast aluminumGloss blackComplex cavities

AI hardware and servers

Heat sinks, chassis brackets and shielding parts that must stay insulating, corrosion resistant and dimensionally stable.

Aluminum alloyFunctional e-coatInsulation

Cross-border hardware OEMs

Black e-coating that meets export environmental requirements (RoHS, REACH) for brands selling across borders.

Export complianceRoHSREACH

Supporting supply chain

We also coat for the tier-1 and tier-2 metalworking shops behind these customers — stamping, die casting, CNC machining and MIM sintering plants.

StampingsDie castingsMIM sintered parts

Note: customer names are cited only to describe capability. Specific programmes, part numbers and volume data are bound by NDA; we can go into detail once one is signed.

CASE DETAILS

Case studies in detail

Each case covers the application, the process difficulty, our solution and the result actually achieved.

Case 01 · Consumer electronics, MIM

Matte black e-coat on MIM hinges and SIM trays

ApplicationMIM precision parts for folding phones and TWS earbuds need a matte black finish that matches the adjacent plastic parts.
Process challenge① MIM sintered surfaces are porous and prone to pinholes. ② Hinges are moving parts, so coating thickness affects assembly tolerance. ③ Multiple parts in one batch must match in color.
Our solutionAdded ultrasonic cleaning and sealing to pretreatment; held coating thickness at 18–22 μm and validated assembly at sample stage; built a master color plaque with a spectrophotometer and compared every batch against it.
Result achieved18–22 μm coating; batch ΔE ≤ 1.0; matte gloss matched to the master plaque; assembly tolerance validated by the customer.
Case 02 · Automotive electronics

High-corrosion black e-coat for automotive motor cores

ApplicationMotor cores and sensor housings that work long term in humid, salt-laden conditions and must also insulate electrically.
Process challenge① The gaps between laminations must be covered. ② Salt spray requirements are strict. ③ Insulation resistance must pass.
Our solutionReworked the phosphating pretreatment for a denser conversion coating; selected a high-corrosion-resistant paint; used throwing power to reach the lamination gaps; tested insulation resistance batch by batch.
Result achievedNSS ≥ 48 h on laminated silicon-steel cores; insulation resistance ≥ 10 MΩ at 500 V DC; adhesion class 0.
Case 03 · Drones

Gloss black e-coat on drone aluminum structures

ApplicationGimbal brackets and airframe aluminum parts are visible components: they need a gloss black look while keeping added weight low.
Process challenge① Gas porosity in die-cast aluminum causes pinholes during baking. ② Complex cavities and deep holes must be covered. ③ No sags or orange peel allowed on visible surfaces.
Our solutionStrengthened degreasing to remove mold release residue; tuned the bake ramp so gas escapes slowly; used throwing power to reach the cavities; matched gloss to a gloss black master plaque with a gloss meter.
Result achievedFull coverage in complex cavities with no misses; uniform coating with no sags; gloss black matched to the master plaque.
Case 04 · Magnetic materials

Anti-corrosion black e-coat for NdFeB magnets

ApplicationSintered NdFeB magnets used in motors and acoustic devices oxidize easily and need a protective coating.
Process challenge① Porous magnet surfaces trap cleaning liquids. ② Too thick a coating closes the assembly air gap. ③ Bake temperature must not demagnetize the parts.
Our solutionDedicated pretreatment and sealing; kept coating thickness in a workable window; confirmed the temperature limit for each magnet grade and adjusted the curing curve accordingly.
Result achievedContinuous coating with no porosity; no loss of magnetic performance.
Case 05 · AI hardware and servers

Insulating e-coat for server shielding and brackets

ApplicationMetal EMI shields and rail brackets inside AI servers must insulate and resist corrosion without interfering with insertion or assembly.
Process challenge① Insulation must pass consistently. ② Coating thickness must not affect rail and insertion tolerances. ③ Coating must not flake off and contaminate the airflow path.
Our solutionApplied a functional e-coat formulation; capped coating thickness tightly; verified adhesion to prevent flaking; sampled insulation resistance batch by batch.
Result achievedInsulation resistance ≥ 10 MΩ at 500 V DC; adhesion class 0; dimensional tolerances met for assembly.
Case 06 · Smart wearables

Fine matte black e-coat on titanium wearable parts

ApplicationMetal structures for smartwatches and smart glasses sit against the skin, so surface feel and sweat resistance both matter.
Process challenge① Titanium's stable oxide film makes adhesion hard to guarantee. ② The finish must be a fine matte. ③ It must resist sweat corrosion.
Our solutionUsed a titanium-specific activation in pretreatment; a matte black formulation that hides fingerprints and fine scratches; matched gloss to the master plaque.
Result achievedAdhesion class 0; consistent matte black gloss; passed sweat corrosion testing.
HOW WE WORK

How we work together

Six steps from first conversation to volume delivery, each with a defined deliverable.

1
Requirement review
Substrate, dimensions, performance requirements and volume
2
Process assessment
Feasibility judgement and a preliminary process proposal
3
Free sample coating
Samples delivered in 3–5 working days for standard parts
4
Data confirmation
Measured coating thickness, ΔE and other data for sign-off
5
Quotation and volume
Quotation after approval, then production scheduling
6
Delivery and support
On-time delivery, batch records archived and traceable
FAQ

Common questions about working with us

Why don't the cases show full customer names?

Most of our customers are under NDA, so we do not disclose programmes, part numbers or volume data without authorisation. Cases are presented by industry + process type in anonymised form, purely to describe process capability and how we solve problems. If you need more background on the customers we work with, we are glad to talk once an NDA is in place.

Can we sign a non-disclosure agreement?

Yes. Drawings, processes and customer information at a metalworking company are trade secrets. We are willing to sign an NDA at the very first meeting and to keep incoming samples and drawings confidential.

Is sample coating charged for new customers?

For standard parts we offer free sample coating. Special substrates, dedicated formulation development or custom racking may incur a charge, which we confirm with you before any work starts.

Want the full process behind a similar part?

Tell us your part type and performance requirements and we will come back with process advice and a sample run.

Request a quote
Call us +86 181 2376 0267