top of page

News & Support

Search

Selecting the Appropriate Thermal Spray Coating Process for Your Application

Choosing the right thermal-spray process is primarily about matching the performance you need to the capabilities and limits of each process. Below Thermach gives a practical, step-by-step decision checklist, a compact comparison of common processes, and actionable next steps you can use immediately.


Decision Checklist


  1. What is the primary function of the coating? (wear, corrosion, rebuild, thermal barrier, electrical, sealing, decorative, lubrication)

  2. What are your required material properties?

    • Hardness / wear resistance

    • Corrosion resistance / chemistry tolerance

    • Thermal barrier (low conductivity) or high thermal conductivity

    • Electrical insulation or conductivity

    • Porosity tolerance (some applications require dense, others porous)

  3. Substrate constraints

    • Heat sensitivity (can it tolerate high preheat or spray heat?)

    • Geometry and accessibility (internal bores, sharp edges, complex shapes)

    • Size and mass (can you move part to spray booth?)

  4. Coating performance targets

    • Required thickness range (microns → millimeters)

    • Bond strength / adhesion requirements

    • Surface roughness / dimensional tolerance (does it need later machining?)

  5. Production / cost factors

    • Volume (prototype vs. high throughput)

    • Process cost, consumables, capital equipment and skill level

  6. Secondary requirements

    • Regulatory / cleanliness constraints (e.g., food, medical)

    • Post-processing (grinding, sealing, heat treat)

  7. Test & qualification

    1. Which tests will prove success? (bond tests, wear tests, salt spray, porosity, microstructure)



Comparison of Thermal-Spray Processes


Plasma Spray

Equipment, Parts & Information for the Thermach Plasma Spray Thermal Spray Coating System

  • Good for: ceramic coatings, thermal barrier coatings (TBCs), insulating layers, dielectric coatings.

  • Strengths: wide material range (oxides, ceramics), moderate build rates.

  • Caveats: coatings usually more porous and brittle than HVOF/cold spray; may require sealing.






High Velocity Oxy-Fuel (HVOF)

Equipment, Parts & Information for the Thermach HVOF Thermal Spray Coating System

  • Good for: dense metallic/ cermet coatings for wear and corrosion (WC-Co, CrC, NiCr).

  • Strengths: very dense, high bond, excellent wear resistance.

  • Caveats: heavier equipment, higher gas/consumable costs.






Electric Arc Spray (Wire Flame / Twin Wire Arc (TWA))

Equipment, Parts & Information for the Thermach Electric Arc Thermal Spray Coating System

  • Good for: economical corrosion/wear coatings, large parts, build-up and repair (steel overlays).

  • Strengths: low cost, high deposition rates, mobile.

  • Caveats: typically rougher, more oxide content; may need machining.






Mapping: Function → Recommended Processes


  • Hard, abrasion-resistant surface (minimize wear): HVOF

  • Corrosion resistance (dense metal): HVOF, Electric Arc Spray TWA for cost-sensitive large parts

  • Dimensional rebuild (low heat): Cold spray (if substrate heat-sensitive) or Electric Arc Spray TWA/wire spray + machining

  • Electrical insulation / dielectric: Plasma Spray ceramic coatings

  • Electrical conductivity / EMI shielding: HVOF with conductive materials

  • Sealing/low friction (tribological): HVOF with cermets, or polymeric spray for bearings/low load



Practical Selection Flow


  1. Pick target materials (e.g., WC-Co for wear, alumina for electrical insulation, NiCr for corrosion).

  2. From materials, eliminate processes that can’t deposit them (cold spray can’t deposit many ceramics; Plasma Spray can’t make the dense metallic layer HVOF makes).

  3. Consider substrate heat sensitivity and geometry (if heat‐sensitive → prefer cold spray or Electric Arc Spray TWA with controlled preheat).

  4. Consider density/porosity requirement (low porosity → HVOF; porous OK → Plasma Spray).

  5. Factor cost/throughput (if large volume and low cost → Electric Arc Spray TWA/wire flame; if performance critical → HVOF/Plasma Spray).

  6. Plan tests (adhesion, wear/corrosion) and a prototype trial.



Surface Prep & Process Control


  • Surface prep: grit blasting to specified profile, clean/dry, remove contaminants.

  • Masking: protect areas not to be coated.

  • Process parameters: powder size, feed rate, stand-off distance, spray angle, substrate preheat. These drastically affect coating quality.

  • Inspection: measure thickness, porosity, bond strength and microstructure; do test coupons before committing.


 

Remember, Thermach is not your competitor; your other options are. We don’t coat; we only supply thermal spray equipment and parts. You can proceed with confidence, knowing that our team is dedicated to creating a custom system that meets your exact specifications.

Manufacturer of Equipment, Parts & Turnkey Solutions for the Thermal Spray Industry.

Manufacturer of Equipment & Parts for the Thermal Spray Industry. Backed by Reliable, Timely Service & Support.


Thermach manufactures thermal spray coating systems for the coating industry. We don't coat. We provide the equipment and parts necessary for you to run a successful coating operation. Our mission is to ensure your coating process is running smoothly with Thermach equipment.

bottom of page