3.4.1 Chemistry and Types of Metallic Bonds
Single layer metallic bonds have a layer height of only the average grit size and a high grit protrusion of 20-70 % of the grit diameter. Because of the high grit
performance, single layered wheels are limited to superabrasives. The metallic single-layer bonds are produced by electroplating, brazing, or electroless plating processes:
• Electroplated wheels—The production takes place at room temperature. The most common bond type for single layer bonds is nickel bonding deposited in an electroplating process. Electroplated CBN wheels were important for the successful development of high efficiency deep grinding (HEDG) [ROWE09].
• Brazed wheels—The production happens at temperatures of up to 1000 °C [MARI04, p. 415]. Strongly wetting solders like titanium containing material, Ni-Cr-Bo-Si-alloys or others are used.
• Electroless plating process—Nickel/phosphor-alloys can be chemically depo — sitioned [KLOC09, p. 61]. Chemically precipitated bonds are of higher strength than electroplated bonds and can have a more even coating thickness, but the equipment is more expensive, processing temperatures are higher and the bond is more brittle [KLOC09, p. 61].