Mechanical, Electrochemical, and Osteoblastic Properties of Gradient Tantalum Coatings on Ti6Al4V Prepared by Plasma Alloying Technique

Abstract

Plasma alloying technique capable of producing metallic coatings with metallurgical bonding has attracted much attention in dental and orthopedic fields. In this study, the effects of temperature and time of plasma tantalum (Ta) alloying technique on the mechanical, electrochemical, and osteoblastic properties of Ta coatings were systematically investigated. Ta coatings prepared at 800 °C possess better interfacial strengths than those prepared at 750 and 850 °C, and the interfacial strength increases with prolonged alloying time (30–120 min). At 800 °C, however, the increased proportion of the soft Ta deposition layer with alloying time in the whole coating impairs the surface mechanical properties of the entire coating, as convinced by decreased microhardness and wear resistance. Moreover, Ta coatings exhibit better corrosion resistance than the Ti6Al4V substrate in Dulbecco’s modified Eagle medium. The enhanced adhesion and extracellular matrix mineralization level of osteoblasts demonstrate the better cytocompatibility and osteogenic activity of the Ta coating. Ta30 (Ta coating prepared at 800 °C for 30 min) exhibits excellent mechanical, electrochemical, and osteoblastic behaviors and is promising in biomedical applications.

Functionally Gradient Coatings from HfC/ HfTaC2 to Ti: Growth Process, Basic Mechanical Properties and Wear Behavior

“…In particular, when ceramic coatings are prepared on metal surfaces, there are composition mutations at the coating-substrate interface and the mismatch of physical properties between metal and ceramic; the phenomenon of coating peeling often occurs due to stress concentration caused by the mismatch of physical properties in actual service. Compared with these deposition techniques, doublecathode glow discharge plasma surface metallurgy technology (DG technology) can realize continuous gradient change in composition between coating and matrix and realize metallurgical combination [30], so as to relieve stress concentration caused by composition mutation, obtain stronger adhesion between coating and substrate, and extend the service life of the coatings [31,32]. In addition, many kinds of gradient ceramic coatings for titanium alloys have been successfully prepared with DG technology by virtue of the above advantages [9,31].…”

“…Compared with these deposition techniques, doublecathode glow discharge plasma surface metallurgy technology (DG technology) can realize continuous gradient change in composition between coating and matrix and realize metallurgical combination [30], so as to relieve stress concentration caused by composition mutation, obtain stronger adhesion between coating and substrate, and extend the service life of the coatings [31,32]. In addition, many kinds of gradient ceramic coatings for titanium alloys have been successfully prepared with DG technology by virtue of the above advantages [9,31].…”