Title: The influence of deep cryogenic treatment and in-situ cryogenic micro turning of Ti-6Al-4V on cutting forces, surface integrity and chip morphology

Authors: T. Jagadesh; G.L. Samuel

Addresses: Department of Mechanical Engineering, Amrita Vishwa Vidyapeetham, Amritapuri, 690525, India ' Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, 600036, India

Abstract: The demand for sustainable manufacturing of axi-symmetric, micro turned titanium based neurosurgical implants are increasing. However, dry micro-turning of titanium alloy at higher cutting speeds, results in poor surface integrity, because of continuous saw-tooth chip formation, chip adhesion, and micro-scratch initiation on the machined surface. To overcome these issues in micro-turning, two techniques were attempted in this paper. First, Ti-6Al-4V is cryogenically cooled for 72 hours and then subsequently heat treated for four hours at 170°C before machining. Second, in-situ cryogenic experiments, liquid nitrogen is fed in the cutting zone. It is observed that, in-situ cryogenic micro-turning assists in ease of chip fracture resulting in good surface finish. It inhibits the formation of saw-tooth chip and thereby a fluctuation of forces with time is limited. Micro-scratch and adhesion of machined chips were present in non-treated and deep-cryogenic treated surfaces whereas, in-situ cryogenically micro-turned surfaces were free from the above defects.

Keywords: micro turning; Ti-6Al-4V; cryogenic treatment; cutting forces; chip morphology; surface finish.

DOI: 10.1504/IJPTECH.2019.100956

International Journal of Precision Technology, 2019 Vol.8 No.2/3/4, pp.312 - 334

Received: 28 May 2018
Accepted: 20 Oct 2018

Published online: 09 Jul 2019 *

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