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The machinability of Ti-6Al-4V alloy has been a constant challenge in the industry, although the material is widely used in the aerospace and medical industries due to its mechanical properties, particularly its strength-to-weight ratio. The current research presents a hybrid laser- and ultrasonic-assisted machining (LUAM) technique to improve the machinability of Ti-6Al-4V alloy in a turning process. This is compared with ultrasonic-assisted machining (UAM), laser-assisted machining (LAM), and convectional turning (CT). The results reveal that UAM and LAM can reduce the cutting forces and surface roughness (Ra) compared to the CT. However, these are achieved mainly at the lowest range of cutting speeds. The hybrid LUAM process demonstrates process improvement with wider range of cutting speeds and depths of cut, which is achieved due to the combined force reduction and thermal softening effect by the hybrid process. [ABSTRACT FROM AUTHOR]

Residual stresses induced by machining coupled with the initial stresses can significantly impact mechanical properties of workpieces such as distortion, corrosion resistance, and dimensional stability. The redistribution pattern of residual stresses is extremely complex. The stress relieving can seriously deform the workpieces and reduce the fatigue life. Therefore, deflection prediction is critical for design, control, analysis, and management of machining. In this paper, an integrated modeling method is introduced to predict the deflection caused by milling residual stresses, to be more exact, to map the relationship between the deflections and the cutting parameters. Response surface design (RSD) is utilized to develop a new mathematical model which can predict the residual stress profiles of the workpieces along the cutting direction based on different cutting parameters. Then, the deflections are derived based on the estimated stress profiles and mechanics of materials theory. A finite element analysis model (FEM)-based simulation experiment using aluminum alloy 6061 as a case study has been implemented. The results from experiments indicate that the proposed approach could precisely estimate the residual stress profiles for given cutting parameters and effectively predict the deflections of the workpieces caused by residual stress. [ABSTRACT FROM AUTHOR]