Forces and Temperatures in Hard Turning

Abstract

& In precision machining, due to the recent developments in 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 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. To enlarge the capability profile of the hard turning process, this paper introduces prediction models of mechanical and thermal loads during turning of 51CrV4 with hardness of 68 HRC by a 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, temperature field for the chip and tool are predicted and compared with experimental measurements. The experimental temperature measurements are conducted by the advanced hardware device FIRE-1 (Fiberoptic Ratio Pyrometer).

Mechanical Characterization and Machinability Behavior of Annealed AISI D6 Cold Working Steel

“…The difference in terms of error is less than 7.7% for surface roughness and less than 6.9% for main cutting force. It proves that the model and equation generated give a fair reading indicating a reasonable model as per the previous study by Lazoglu et al [21]. The results obtained also validated the reliability of the model.…”

Prediction and optimization of cutting temperature on hard-turning of AISI H13 hot work steel

“…When thermal aspects are coupled with mechanical aspects, this will result in rapid tool wear. Tool wear, not only reduces the tool life and increases the machining costs, but it also increases the forces and tensile residual stresses affecting the surface quality and causing white layer surface damages [7]. These generated white layers possess a negative effect on surface finish and fatigue strength of the final product.…”

Tool Stresses in Soft and Hard Finish Turning with Low Content CBN Tool by Finite Elements Analysis

“…It is known that precision hard turning has many advantages compared with grinding, such as short cycle time, process flexibility, reasonable surface finish, higher material removal rate and lesser environment problems without the use of cutting fluid [2][3][4]. On the other hand, Lazoğlu et al [5] have shown that early tool wear, tool breakage, chipping, tool stresses, cutting temperatures, residual stresses, white layer phenomena, machined surface quality and surface integrity are very important issues in hard machining industrial applications.…”