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ORIGINAL ARTICLE
Case-based reasoning (CBR) model for hard machining process Anthony M. Xavior & Margret S. Anouncia
Received: 6 September 2011 / Accepted: 7 February 2012 / Published online: 18 April 2012 # Springer-Verlag London Limited 2012
Abstract In this research paper, hard machining of two materials viz. AISI 52100 (bearing steel) and AISI D2 (tool steel) at a hardness of 55 HRC is addressed. Taguchi’s technique is used for the design of experiments. Eight different parameters are considered for the experimentation in order to perform comprehensive investigations on hard machining process. Case-based reasoning (CBR) model is developed for predicting the machining performance and its capability is evaluated by conducting validation experiments. The root mean squared error, mean absolute percentage error, and the correlation coefficient between the actual and the model-predicted values of surface roughness and tool life are evaluated to confirm the validity of the CBR model. Keywords Hard machining . Surface roughness . Tool life . Case-based reasoning
1 Introduction Hard machining is the process of finish machining heattreated steel (in the range of 45–65 HRC) shafts, gears, pinions, and various automotive components using cBN, PcBN, cermet, ceramic, and multicoated carbide inserts. Many researchers had addressed about hard machining of AISI D2, AISI 52100, H13, 16MnCr5E, 17CrNiMo6E, and A. M. Xavior (*) School of Mechanical and Building Sciences, VIT University, Vellore 632 014 Tamil Nadu, India e-mail: [email protected] M. S. Anouncia School of Computing Sciences, VIT University, Vellore 632 014 Tamil Nadu, India
31CrMo12 for different applications. Coated carbides are basically a cemented carbide insert coated with one or more thin layers of wear-resistant material, such as titanium carbide (TiC), titanium nitride (TiN), titanium carbide nitride (TiCN), and aluminum oxide. It is well known that thin, hard coatings can reduce tool wear and improve tool life and productivity. Therefore, most of the carbide tools used in the metal cutting industry is coated [1]. Since tool wear has significant influence on the dimensional accuracy of products and the surface roughness of the parts machined attempts were made to prevent this effect. In order to improve wear resistance and prevent oxidation of tool materials during machining, tools with multicoated layers are now commonly used in researches on turning materials with high hardness values [2]. Wang [3] reported that TiAlN coating layer on carbide substrate had high thermal and oxidation resistance at high temperature application. As such, it gave improved cutting efficiency as well as better resistance of the tool to wear than TiN and TiCN coatings during machining process. TiCN-based cermets provide improved surface finishing and excellent chip/tolerance control and permit the geometrical accuracy of workpiece [4]. It has been reported that from a machining point of view TiCN contributes to resistance to diffusion and adhesive wear, vanadium carbide i
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