A Review of Additive Mixed-Electric Discharge Machining: Current Status and Future Perspectives for Surface Modification of Biomedical Implants

Table 6

Critical review of recent development of material deposition and surface treatment of metallic implant through AM-EDM.

Electrodes combination	Powder type/conc.	Deposited layers	Findings	Refs.
Grade IV Ti/Ti	Ti/3 & 6 g/L	(i) TiO; (ii) Recast layers	(i) With 3 g/l microcracks observed and disappeared when using 6 g/l of Ti; (ii) Recast layer thickness increases with increase in current duration and Ti powder concentration; (iii) Hydrophilic surface good for dental implant was observed	[86]
Grade II Ti/Ti	—	(i) TiO	(i) Dual surface topography with micron and submicron topographies sufficient for orthopedic and dental applications	[87]
AISI D2 steel/Ti	Ti/2 g/L	(i) TiC	(i) Significant Improvement in surface roughness; (ii) Shallow craters and craters diminishes; (iii) Ti atoms higher in the cracks area	[88]
β-Ti alloy (Ti-Na-Ta-Zr)/Cp-Ti	Si/0, 2, 4, 6 & 8 g/L	(i) Bioceramic oxides; (ii) Carbide phases	(i) EDMed surface hardness twice the pure sample; (ii) 4 g/L of Si powder produces thin recast layer; (iii) A nanoporous, bioactive and biocompatible surface achieved	[11]
Ti-6Al-4V/Ti	HA/5, 10, 15 & 20 g/L	(i) HA	(i) AM-EDM can be used as alternative for HA reach layer deposition on the substrate; (ii) AM-EDM produces biocompatible coating for medical applications	[89]
Ti-6Al-4V/Cu	Surfactant + Graphite (Gr) 1–20/gL	(i) Recast layer	(i) RLT layer reduced with 6 g/L of surfactant which becomes evenly distributed with 10 g/L of Gr; (ii) Less microcracks were also observed; (iii) Surfactant inhibit a powerful material migration	[38]
Ti-6Al-4V/Ti	HA	(i) HA	(i) Moderate pulse-on current and pulse-on duration are possible settings that will produce material deposition	[90]
Grade IV Ti/Cu	—	(i) TiO2; (ii) Nano TiH	(i) A nanoporous, nanostructured and bioactive TiO2 layer with short duration; (ii) Improved biocompatibility was achieved	[19]
Fe-Al-Mn/Cu	—	(i) Recast layer; (ii) Oxide layer; (iii) k-carbide phase	(i) Nanostructured recast layer was formed; (ii) Increased biocompatibility	[91]
WC90-Co10/Cu	Ti	(i) TiC	(i) Improved hardness with reduced microcracks	[92]