%0 Journal Article
%T Observation of Drilling Burr and Finding out the Condition for Minimum Burr Formation
%A Nripen Mondal
%A Biswajit Sing Sardar
%A Ranendra Nath Halder
%A Santanu Das
%J International Journal of Manufacturing Engineering
%D 2014
%R 10.1155/2014/208293
%X Suppression or elimination of burr formation at the exit edge of the workpiece during drilling is essential to make quality products. In this work, low alloy steel specimens have been drilled to observe burr height under different machining conditions. Taper shank, uncoated 14£¿mm diameter HSS twist drills are used in these experiments. Dry environment is maintained in experiment set I. Water is applied as cutting fluid in experiment set II. In the next four sets of experiments, the effect of providing back-up support material and exit edge bevel is observed on formation of burr at the exit edge of specimens under dry and wet conditions. It is revealed that an exit edge bevel of 31 degrees with water as the cutting fluid gives negligible burr at the exit edge of the drilled hole at certain machining conditions. Use of a back-up support can also reduce drill burr to a large extent. In this paper, artificial neural networks (ANN) are developed for modeling experimental results, and modeled values show close matching with the experimental results with small deviations. 1. Introduction Drilling is a common hole-making operation, and the majority of workpieces are subject to hole-drilling before they leave a machine shop. However, presence of burr on the drilled workpieces creates problems not only in handling, but also in the assembly line. Burrs are undesired projections attached to the edge of drilled holes. These are found to be substantially greater at exit side than entry side. Hence, elimination, or large-scale reduction, of exit burr is the necessary requirement of an industry [1¨C5]. Many researchers worked on burr-related problems associated with drilling and other processes and also investigated the mechanism behind burr formation. Control charts were applied by Min [6] and Kim et al. [7] for control and prediction of burr height during drilling different steels. The same technique was also employed by Lee and Dornfeld [8] for estimating burr size during microdrilling to some success. Finite element method (FEM) was used by some others [9¨C11] to observe stress and deformation patterns analytically to understand the reason behind burr formation. Guo and Dornfeld [9] made finite element analysis to assess the substantial reduction of drilling burr with back-up support. They also successfully did [10] this analysis to understand burr formation in stainless steels. FEM was also used by Park and Dornfeld [11] to find out the influence of exit edge angle of a specimen, tool rake angle, and back-up support on burr formation. The estimates made showed
%U http://www.hindawi.com/journals/ijme/2014/208293/