Research in Metal Cutting

Several researchers tried to replace the single-shear plane model by a shear zone model. Lee and Shaffer (1951) provided a slip-line solution by applying the theory of plasticity. In the slip-line model, the metal is assumed to flow along the line of maximum shear lines. The slip-line field solution cannot be applied easily to three-dimensional as well as strain-hardening cases. Sidjanin and Kovac (1997) applied the concept of fracture mechanics in chip formation process. Atkins (2003) demonstrated that the work for creation of new surfaces in metal cutting is significant. He also points out that Shaw (1954) has shown this work to be insignificant. However, when this work is included based on the modem ductile fracture mechanics, even the Merchant analysis provides reasonable results. 

Dwaihl (1940), Trent (1952) and Trigger and Cho (1956) conducted a number of fundamental studies on various aspects of tool wear of cemented carbide tools. There are mainly two types of wear, viz. flank wear and crater wear. Crater wear starts on the rake face at some distance away from the tool nose, as the maximum temperature is attained at this point. It is a diffusion-dominant wear, and temperature plays an excessive role in it. The flank wear occurs at the flank surface and affects the dimensional accuracy to a great extent. Recently, Astakhov (2004) has argued that the existing measures of flank wear are insufficient for its characterization and he has proposed new concepts. 

A careful study of literature reveals that a lot of research on metal cutting mechanics has been carried out since last one and half century. Although a number of models were proposed for the estimation of cutting forces, most of the textbooks give more emphasis to Merchant s analysis based on the single-shear plane model. 

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