Tungsten Carbide Coating - Basic Information Required

A. There are three commonly methods to deposit tungsten carbide (WC) over ferrous substrates. Two involving extreme heat are: a) Welding with steel or alloy rods loaded with WC powder (low percentage of WC, heat distortion and surface irregularities as any weldment). b) Thermospray and fuse with WC+Alloy powder (medium content of WC, heat distortion and a slight better surface). c) HVOF. This involves the use of high tech equipment that sprays at supersonic velocities a mixture of high content of WC+Cobalt (88%+12%). This high impact produces a very good bond when the surface is properly prepared and is considered to be low-temperature. Surface like a fine emery paper. After grinding is considered a substitute for chrome in certain applications.

A. Tungsten carbide is also deposited by PVD and electro-spark deposition. The PVD-deposited WC is not a good substitute for hard chrome -- it's used more as a solid lubricant, having a high C content. Electro-spark deposition is a welding process carried out at room temperature. While the coatings are quite good -- better than hard chrome -- and the coating equipment quite affordable, the process is not well-suited for coating large objects.

A. John,

In answer to your question regarding tungsten carbide coating hss slitting blades for your packaging equipment.

Depending on the type of equipment being used to deposit the carbide, via spark generation, heat is a factor.

The use of a unit which uses 3 phase power and has a series of internal transformers and rectifier is your best choice. The Carbumatic machine is one of the best available to do the job for you. I have been using this equipment for the past 40 years with excellent results,

You can keep the edges sharp without sharpening afterward and you will not anneal the tool.