Dry and Compressed Air Cooling Comparative Study on 6061 Aluminium Alloy Drilling Using Coated Drill

Abstract

The use of aluminium alloy in the manufacturing industry has increased tremendously in the past decade mainly in the areas of aeronautics and automobiles. The ease of machinability of this material makes it a more desirable operand in manufacturing usage. Hence, in this research, a study was undertaken to perform a comparative analysis of dry and cold air drilling on 6061 aluminium alloy. The drill tool used in the drilling process was HSS Cobalt coated tool which has not featured in many research papers. Subsequently, the quality of each hole was identified based on the diameter accuracy of the hole and the surface roughness of the hole. A variation in the parameters was employed to identify the best feed rate and spindle speed that can accommodate a quality hole. In addition, during the drilling operations, force was measured to analyse the ensemble of parameters that present the highest and lowest force. Based on the data collected, an analysis was performed to identify the best quality hole. The force measured for cold air drilling was relatively lower than those measured in dry drilling primarily when high feed rate of 80 mm/min and high speed of 6000 rpm is used. The surface roughness and hole diameter does not differ much between cold air and dry drilling. Therefore, it is highly recommended that feed rate of 80 mm/min coupled with a spindle speed of 6000 rpm be used for drilling operations with a 5mm diameter tool.