Influence of cutting conditions on surface characteristics in micro-milling of Ti-6Al-7Nb alloy

Abstract

Ti-6Al-7Nb alloy is widely used in the manufacturing of medical implant. In this work, experimental study on micro-milling of Ti-6Al-7Nb is exemplified to analyze cutting conditions effect on surface texture. Process variables including cutting speed (vc), feed rate (fn) and depth of cut (ap) are considered. Responses in the form of surface topography variables including Average Surface Roughness (Ra), Maximum Average Profile Height (Rz) and Maximum Profile Peak Height (Rp) are measured. Dental implants are generally micro and miniature in nature to ensure functionality of a human bone. Hence, 20 micro-slot of 500 μm size are produced using Carbide end mill cutter under dry condition. Surface plots are drawn and are observed that ‘ap’ possess foremost effect on surface quality. Minimum ‘ap’ yields good surface finish of 0.1 µm. Analysis of variance also proves ‘ap’ effects on surface quality. Surface morphology study reveals grooves formation and particle deposition on finished surface at excessive ‘ap’ condition. Burr formation analysis shows the development of knife edge and wave-type burr for lower and higher ‘ap’ conditions, respectively. Hence, it is inferred that at lower ‘ap’ values (60 µm), desired surface finish of 0.1 µm is achieved in Ti-6Al-7Nb alloy that promotes better osseo-integration.