How Carbide Coatings Extend Tool Life

Introduction

Coatings are applied to carbide tools and dies to reduce friction, resist heat, and prevent material pickup. A properly selected coating can double or triple tool life compared to uncoated carbide.

Common Coating Types

TiN is a gold-colored coating that reduces friction and resists built-up edge. TiC provides high hardness and wear resistance. TiCN offers higher temperature resistance. Al2O3 coatings act as thermal barriers.

PVD vs CVD Coatings

PVD coatings are applied at lower temperatures, preserving carbide substrate properties. They are thinner and provide smoother surfaces. CVD coatings are thicker and offer better heat resistance but involve higher temperatures.

How Coatings Work

Coatings create a barrier between the carbide substrate and the workpiece. They reduce friction, dissipate heat, and prevent chemical adhesion. This means tools run cooler, cut cleaner, and last longer.

Coating Selection

Select coatings based on workpiece material and operation. TiN is general purpose. TiCN suits steel machining. Al2O3 is for high-speed cutting. For stamping, DLC or TiN coatings reduce galling on non-ferrous metals.

Limitations

Coatings add a small amount of thickness that may affect tight clearances. They can also chip if the tool experiences severe impact. For heavy stamping, uncoated or thinner coatings may be more appropriate.

Conclusion

Carbide coatings are a cost-effective way to dramatically extend tool and die life. Understanding coating types and applications helps select the right solution for each cutting or forming operation.

References

GB/T 7714: GUPTA R, SONG J. Powder metallurgy processing and mechanical properties of cemented tungsten carbide composites[J]. International Journal of Refractory Metals and Hard Materials, 2020, 91: 105246.

APA 7th: Gupta, R., & Song, J. (2020). Powder metallurgy processing and mechanical properties of cemented tungsten carbide composites.

MLA 9th: Gupta, R., and J. Song. "Powder Metallurgy Processing and Mechanical Properties of Cemented Tungsten Carbide Composites."