Mechanics and Dynamics of Hard Turning Process

Abstract

In precision machining, due to the recent developments on the cutting tools, machine tool structural rigidity and improved CNC controllers, hard turning is an emerging process as an alternative to some of the grinding processes by providing reductions in costs and cycle-times. In industrial environments, hard turning is established for geometry features of parts with low to medium requirements on part quality. Better and deeper understanding of cutting forces, stresses and temperature fields, temperature gradients created during the machining are very critical for achieving highest quality products and high productivity in feasible cycle times. In order to enlarge the capability profile of the hard turning process, this paper introduces to prediction models of mechanical and thermal loads during turning of 51CrV4 with hardness of 68 HRC by CBN tool. The shear flow stress, shear and friction angles are determined from the orthogonal cutting tests. Cutting force coefficients are determined from orthogonal to oblique transformations. Cutting forces and surface profiles are predicted and compared with experimental measurements.

Precision machining of an aluminum alloy piston reinforced with a cast iron insert

“…10 Due to recent cutting tool developments, as well as the improved machine tool structural rigidity and better CNC controllers, hard turning is emerging as an alternative process to grinding due to its reduced cost and cycle time. 11 The high CBN content of CBN tools (as much as 90%) gives a better surface finish, 12 but the geometry of the cut evolves considerably over the lifetime of a CBN tool. 13 In the past, two different tools and two different machining parameters were used to machine bimetallic components.…”