It is important for cutting blades, including but not limited to rotary cutting blades, to maintain a sharp and durable cutting edge throughout the life of the blade. One technique that has been used to increase the wear resistance of the cutting edge is to apply a layer of a harder material to the surface of the cutting blade that will resist wear. Often referred to as hard-facing, a number of different techniques exist for performing such an operation.
Some hard-facing methods involve mixing a powdered metal alloy with certain solvents to form a slurry, which is then applied to the metal surface of the cutting blade. The blade is then heated to cause the metal alloy to adhere to the metal of the cutting blade. Other hard-facing techniques include high velocity oxygen formation (HVOF). HVOF typically includes injecting the hard-facing metal alloy in powder or solid form into a high temperature high velocity flame. The flame accelerates the metal particles toward the metal blade and melts the hard-facing onto the surface of the base metal.
Though these hard-facing processes result in cutting blades having extended wear surfaces, they have several deficiencies, including, but not limited to, an unreliable bond created between the hard-facing material and the cutting blade base metal such that the hard-facing is prone to delaminating, chipping, or flaking during operation; the processes involved can impact the overall heat treatment of the cutting blade and therefore negatively impact the blade characteristics, such as making the blade more brittle and prone to cracking or shattering; and these processes are often expensive, laborious and can generate a substantial amount of waste material, which may be hazardous in nature.