Life cycle assessment of cubic boron nitride grinding wheels

• Investigation of the environmental impact and trade-offs when comparing different grinding wheel abrasive and hub materials.
• Uncovering the inventory data for the production processes of a cBN grinding wheel based on a patent and literature study.
• Environmental impact assessment for a cradle-to-gate tool production and cradle-to-grave of an external grinding process.
• Using life cycle assessment method to identify their environmental hotspots and the influencing factors.
• Contribution to increase transparency to support manufacturers and users in improving the environmental sustainability.

To reduce the environmental impacts caused by manufacturing processes science, and industry want to identify hotspots and to derive improvement measures. One of those contributing manufacturing processes is grinding using synthetically produced cubic boron nitride (cBN). CBN grains are broadly applied for super abrasive materials in the production of high-precision grinding wheels. The shape, size and volume concentration of the cBN grains have a major impact on the technological results (workpiece roughness, tool wear, temperature, etc.) of the grinding process and on the economic value of the grinding wheel. Despite the technological results and the economic value, the contribution of cBN grinding wheels to the overall environmental impact has not been fully investigated and understood. A key method to calculate the environmental impact is life cycle assessment. However, an essential requirement is the availability of the used material and energy data during the life cycle stages of grinding wheel material, production, application and disposal. This paper gives an overview regarding the needed materials and energy during the different life phases of a cBN grinding wheel. On this basis, the detailed environmental impact of the grinding process is presented in a case study.