Determination of the Deformation State of a Ti-6Al-4V Alloy Subjected to Orthogonal Cutting Using Experimental and Numerical Methods
Abstract
Orthogonal cutting of Ti-6Al-4V alloy was studied. Surface roughness, chip thickness and shear band frequency increased with the feed rate and cutting speed. Serrated chips were formed due to shear band. Strain and flow stress distributions in the material ahead of the tool tip were estimated from shear angle measurements and microhardness measurements respectively. The stress-strain data obtained in this way was used in numerical models. Two numerical models were developed by using two-dimensional Lagrangian element formulation and Smoothed-particle hydrodynamics formulations employing the Johnson-Cook constitutive relationship that utilised the experimental data generated from the machined material with the damage criteria. The Lagrangian element formulation predicted the strain and temperature generated in the material ahead of the tool tip as 1.65 and 1222 K respectively, which were in agreement with the experimental strain (1.65) and temperature (1217 K). The predicted results using Lagrangian element formulation correlated well with the experimental findings.