Why Do We Passivate Carbide Cutting Tools?

Why Do We Passivate Carbide Cutting Tools?

During CNC machining, the workpieces are expected to achieve superior quality and work for many years without losing performance. However, cutting tools that need grinding wheels for sharpening tend to have microscopic gaps

with varying degrees. As the tool cuts, the gap may expand, leaving room for accelerated tool wearing and damage.

What is Tool Passivation?

Tool passivation is the process of enhancing the life of a tool through polishing, leveling, and deburring. This single process after a grinding cycle before a coating is not generalized. However, it is primarily applied for finishing stainless steel to prevent corrosion. Carbide tool manufacturers use nitric and citric acid to eliminate the free iron on the surface. Such chemical treatment processes provide a protective oxide layer that will not react chemically with air to cause corrosion.

Why is Tool Passivation Necessary?

When using ordinary or diamond grinding wheels, there are various micro notches from chipping to saw edge on the tool being ground. As the tool cuts, the micro notch can easily expand, increasing tool damage and wearing.

Main Effects of Tool Passivation By rounding the cutting edge, it removes the burr of the cutting edge to achieve precise and consistent reverse circle processing. However, the cutting-edge burr leads to wearing the tool and roughening the workpiece surface.

 Polishing Treatment of Tool Grooves All-round polishing of the tool grove can enhance the surface quality and effectiveness of row cutting. A cutting groove with a smooth surface ensures better chip removal and higher cutting speeds.

 Polishing the Coating After removing the tool coating, the small droplets can significantly impact the surface finish and maximize the adsorption of oils during lubrication. In addition, after the coating process, the surface tool loses its smaller protruding droplets. As a result, it improves the roughness of the surface, making the tool easy to produce high-friction heat to reduce cutting speeds.

Contact Company Name: PDQ Workholding and Tooling Contact No: 260-244-2919 Website: https://www.pdqwh.com/

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