Heat-flow determination through inverse identification in drilling of aluminium workpieces with MQL

Abstract

One of the current trends in machining is the reduction or elimination of the use of cutting fluids to reduce economic and ecological costs. As a consequence, heating of the workpieces is increased, leading to greater thermal distortion. This distortion can be predicted using the finite-element method (FEM), provided heat input to the workpiece for the machining operation is known. The aim of this research is to determine the quantity and ratio of heat generated in drilling operations and to quantify the heat transferred to the workpiece based on cutting speed and feed rate. Thus, a detailed study of workpiece heating during the drilling process with minimum quantity of lubricant was conducted, and a combination of experimental and numerical data was used to obtain these parameters. The experiments were carried out on aluminium (Al2017) samples. Drilling torque and temperature of the workpiece were measured. The cutting procedure involved drilling a O10 × 15 mm blind hole using uncoated cemented carbide tools. Temperature was measured by infrared methods, and cutting torque was obtained using a piezoelectric dynamometer. The FEM model was developed using the general-purpose software ABAQUS/Standard© v6.5 and the inverse simulation technique was used to calculate heat input to the workpiece for each machining condition. As a general conclusion, an increase in cutting speed and feed rate leads to a decrease in heat input and temperature in the workpiece and thus, thermal distortion of the part.