A feasibility study of promoting osseointegration surface roughness by micro-milling of Ti-6Al-4V biomedical alloy

Abstract

The reliability of a prosthetic implant needs durability, biocompatibility, and osseointegration capability. Accomplishing these characteristics, Ti-6Al-4V alloy is the main used material for implant fabrication. Moreover, it can be processed by additive manufacturing technique, permitting to meet the needs of patience-tailored, often complex shaped, prosthesis topologies. Once an implant is realized, it is finished by machining operations and its osseointegration capability is heavily influenced by the resulting surface roughness. Consequently, the assessment of this latter is mandatory to evaluate the prosthesis durability. This paper presents the analysis of surface roughness of Ti-6Al-4V micro-milled specimens produced by plastic deformation, selective laser melting, and electron beam melting processes. A central composite design was employed for planning the cutting tests. The comparison between surface roughness results and its values for enhancing osseointegration, firstly permitted to individuate the range of micro-milling suitable applications, which have been individuated as ball joints, bone plates, and screws. Next, the statistical analysis of the experimental measurements allowed the identification of the most influential micro-milling parameters together with the determination of the mathematical models of surface roughness by response surface methodology. The good comparison among calculated and experimental results revealed the reliability of the model, allowing the prediction of achievable surface roughness once micro-machining parameters are selected, or their optimization as a function of a desired surface roughness value.

Tool Run-Out in Micro-Milling: Development of an Analytical Model Based on Cutting Force Signal Analysis

“…It greatly affects the accuracy of micro-milling, in contrast to conventional milling, where the same phenomenon has neglectable effects. Tool run-out leads to increased tool wear [ 18 ] and a reduction in the surface quality for the finished parts [ 19 ], and it makes force prediction more difficult. An analytical model for predicting the surface topology when micro-milling three different materials, namely 40HM steel, Al7035 aluminum alloy, and Ti-6Al-4V titanium alloy, was proposed in [ 20 ].…”

Systematic review of optimization techniques for laser beam machining

“…The applicability of LBM across a wide variety of fields and activities is illustrative of the cutting-edge character of this machining method. There is a wide range of industrial sectors that benefit from LBM, including aerospace and automotive, as well as electronics and medical device manufacturing [14][15][16][17][18]. It is used in the aerospace industry to help build lightweight components with precise geometries while simultaneously minimising heat-affected zones.…”