Additive Manufacturing of cBN-Copper Grinding Wheel Coatings via High Pressure Cold Gas Spraying

Additive manufacturing of grinding wheel coatings using cubic boron nitride (cBN) as the abrasive and copper as the matrix material offers significant advantages in grinding applications, particularly for processing hard-to-grind materials such as hardened steels and superalloys. cBN, compared to diamond, exhibits superior thermal stability and chemical resistance when grinding ferrous materials. Copper, as a matrix material, provides excellent thermal conductivity and ductility, helping to dissipate heat generated during grinding and enhancing tool life and performance. This study investigates the cold gas spraying (CGS) process as an innovative approach for fabricating cBN-copper composite coatings. CGS, a low-temperature thermal spray and additive manufacturing process, prevents thermal degradation of sensitive materials such as cBN and ensures a dense coating with a high bond strength. This research focuses on key parameters such as primary gas temperature and pressure as well as the ratio of cBN to copper, analyzing their effects on coating performance. Preliminary experiments show promising results regarding hardness, bond strength and cBN content and suggest that optimizing the spraying parameters could provide coatings suitable to be prepared for a grinding application. The cold gas spraying process thus promises a flexible alternative to conventional methods for producing high-quality grinding wheel coatings.