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.
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 *