Ti6Al4V Surface Modification by Hydroxyapatite Powder Mixed Electrical Discharge Machining for Medical Applications

Abstract

Titanium surface modification by the Hydroxyapatite (HA) mixed Electrical Discharge Machining (EDM) is an alternative and promising technique to enhance the biocompatibility and to promote the biological performance in bone, which is dependent on surface properties, such as surface roughness, chemistry, and wettability. HA powder is used for the first time with electrical discharge machining to improve osteoblastic cell activity on the developed surfaces for Ti6Al4V. Different HA concentrations in deionized water were tested as an experimental variable during EDM. Abrasive polishing and electrical discharge machined control surfaces without powder addition also analyzed to compare the results. The surface characteristics of analyzed samples were evaluated by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-Ray Diffractometry (XRD), white light interferometry, and contact angle measurements. The wettability tests suggest that the hydroxyapatite powder mixed EDM'ed surfaces shows highly hydrophilic characteristics compared the other surfaces, abrasive polished and EDM'ed without powder addition in the dielectric. The results from the MTT assay revealed that those surfaces modified using HA powder addition in distilled water dielectric liquid promoted the most significant cell attachment/growth. The results indicate that HA powder mixed EDM offers a promising method for the surface modification of biomaterials such as titanium alloys.

A comprehensive review on metallic implant biomaterials and their subtractive manufacturing

“…For instance, with variation in the powder characteristics (particle sizes and concentrations) of SiC and Al 2 O 3 powders and dielectric mediums (such as EDM oil, deionized water, and tap water), considerable changes in the surface roughness (SR), recast layer thickness (RLT), material subtraction/removal rate (MRR), and tool wear rate (TWR) were witnessed [ 225 – 227 ]. Besides, the literature also records a noteworthy improvement in the biological response of PM-EDMed Ti alloys when the enhanced biocompatibility, osteoblastic cell activity, and bone-bonding ability were achieved using hydroxyapatite (HA) [ 228 – 230 ]. Two recent articles used silver nanopowder and obtained remarkable improvement in the antibacterial properties of PM-EDMed Ti-6Al-4 V alloy [ 215 , 231 ].…”

On the machinability and properties of Ti–6Al–4V biomaterial with n-HAp powder–mixed ED machining

“…To carry out the experimentation, ZNC EDM (S645, OSCARMAX, Taiwan) with a specially fabricated tank was employed and a pump for uniform mixing of powder was used as part of the setup (Figure 1). The experiments were conducted based on the Taguchi design with a five-factor mixed level setup and orthogonal array of L 16 (2) 15 . The experimental variables and their levels are shown in Table 2.…”

“…It has been recently indicated that it is possible to deposit HAp powder on the surfaces of different types of Ti alloys. [16][17][18][19][20] However, machining parameters of PMEDM can influence the properties of the final product (e.g. surface roughness (SR)) and the productivity of machining process (e.g.…”

Surface engineering of biomaterials in orthopedic and dental implants: Strategies to improve osteointegration, bacteriostatic and bactericidal activities

“…Additionally, recent progress of surface modifications on hard tissue applications apart from surface coating strategy are introduced in Table S2. [ 167–181 ] It is suggested that physicochemical cues of the surface are intrinsically linked as the alteration of the surface topography will lead to localized changes in surface chemistry, and vice versa.…”

“…We first focused on plasma sprayed CaP coatings on metallic implants and possible techniques to address their limitations including phase S2. [167][168][169][170][171][172][173][174][175][176][177][178][179][180][181] It is suggested that physicochemical cues of the surface are intrinsically linked as the alteration of the surface topography will lead to localized changes in surface chemistry, and vice versa.…”