Ecological grinding with chilled air as coolant

Abstract

Compared with other machining processes, grinding consumes the highest specific energy. Therefore, the use of a water-based coolant is often necessary to overcome thermal damage, to impart better surface integrity and to achieve higher tool life. However, the presence of hazardous chemical additives in the coolant causes environmental problems. As a result, stringent government legislation is being imposed for coolant use and disposal, which could represent up to 7–17 per cent of the total machining cost. This paper reports the development of an ecologically friendly grinding technology that uses chilled air with a biodegradable oil and air mist to replace the conventional water-based coolant. A thermal energy equilibrium model that relates to the grinding energy, heat transfer and internal energy rise was used to discuss the grinding results. This model predicted the maximum material removal for chilled air grinding, which was in agreement with the experiments.