Title: Surface integrity and chip morphology in Ti-6Al-4V machining under CO₂ cooling with vortex tube

Authors: Khirod Mahapatro; P. Vamsi Krishna

Addresses: Department of Mechanical Engineering, National Institute of Technology Warangal, Warangal, Telangana State, Telangana, 506004, India ' Department of Mechanical Engineering, National Institute of Technology Warangal, Warangal, Telangana State, Telangana, 506004, India

Abstract: Machining titanium alloys is a difficult job due to high heat generation and shorter tool life attributed to their inherent properties. In Ti-6Al-4V machining, the segmented type chips are formed with poor surface integrity, and tensile residual stresses are generated on the surface of machined components. The difficulties arising in titanium alloy machining can be minimised by removing the heat effectively. In the present work, vortex tube cooling system (VTCS) is used to supply the cold CO₂ gas. Chip morphology, surface quality, tool wear, and surface residual stresses are analysed and compared to dry cutting. The experimental results revealed that VTCS reduced the width of segmented chips and reduced flank wear by up to 48% relative to dry cutting. Crater wear zone width is reduced slightly, and notch wear is almost eliminated. Chip segments and accumulated edge fragments are decreased on the machined surface, and compressive surface residual stresses are developed.

Keywords: vortex tube; CO₂ gas cooling; chip morphology; surface morphology; tool wear; and surface residual stresses.

DOI: 10.1504/IJSURFSE.2023.134786

International Journal of Surface Science and Engineering, 2023 Vol.17 No.3, pp.165 - 179

Received: 07 May 2022
Accepted: 08 Aug 2022
Published online: 10 Nov 2023 *

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