SHAFT RESTORATION METHOD
HARD COATING SOLUTION FOR FINISHED MACHINED PARTS
Finished machined parts, which have reached final dimensions and assembly tolerances, are often high-precision components. Applying a hard coating to enhance wear resistance and extend service life is necessary, but the process must not alter the original shape.
WELDING METHODS (LASER, TIG, MIG) ARE NOT SUITABLE
| Technology | Advantages | Serious Drawbacks for Finished Machined Parts |
|---|---|---|
| Laser Welding | Concentrated energy, high precision | Still causes localized thermal stress, which can lead to deformation, cracking, warping. High cost. |
| TIG Welding | Good weld quality, easy arc control | High heat input causes significant distortion, cannot maintain tolerances. |
| MIG Welding | High productivity, easy to operate | Strong thermal impact causes major deformation, unsuitable for precision parts. |
Risks of Welding:
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Residual stresses after welding may cause warping or shrinkage.
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Heat-Affected Zone (HAZ) can degrade base material hardness and cause cracking near the weld.
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Thin or unevenly shaped parts are at high risk of complete failure.
OPTIMAL SOLUTION: TWIN-WIRE ARC SPRAY COATING
1. Twin-Wire Arc Spray
– An ideal industrial solution
This is the most efficient and cost-effective solution for hard coating:
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Does not melt the base surface, only melts the spray wire → no deformation.
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Extremely low substrate heat input (~150°C) → preserves geometry and dimensions.
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Various wire alloys can be used depending on requirements: wear-resistant, heat-resistant, corrosion-resistant.
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Reasonable investment cost, easily integrated into production lines.
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Precise control of coating thickness, no need to re-machine the finished surface.
⇒ Conclusion:
Arc Spray is currently the optimal solution for hard coating finished machined parts, especially those requiring high precision.
SUMMARY CONCLUSION
Finished machined parts require a coating method that does not cause deformation or thermal impact, and maintains assembly tolerances.
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Welding technologies (Laser, TIG, MIG) are unsuitable due to heat input and deformation.
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Twin-Wire Arc Spray is the best solution: safe, effective, cost-efficient, and easy to implement.
