Corrosion depth profiles of nitrided titanium alloy in acidified sulphate solution

Abstract

Abstract:© Versita Sp. z o.o. Keywords: Titanium • Nitriding • Electrochemical corrosion • Depth-profile Research ArticleThick (400 µm) glow-discharge nitrided layers, TiN+Ti 2 N + αTi(N) type, have been produced on the Ti-1Al-1Mn titanium alloy. Using a progressive thinning method, the polarization characteristics at different depths of nitrided layers have been measured. From the plots of obtained potentiodynamic polarization curves the depth profiles of characteristic anodic and cathodic currents (at potentials corresponding to (a) hydride formation, (b) hydrogen evolution, (c) primary passivation, (d) oxygen evolution and (e) secondary passivation) as well as polarization resistance have been determined in 0.5 M Na 2 SO 4 solution acidified to pH = 2. The anomalously high slope of the polarization curves in the cathodic region has been ascribed to the formation of titanium hydride. It has been shown that outer nitrided layers (up to 25 µm) exhibit excellent acid corrosion resistance owing to strong inhibition of the anodic process by TiN phase. Corrosion resistance of deeper situated layers gradually decreases and at depths of 250-370 µm the corrosion process is accelerated by presence of TiO 2 precipitations. Nitrided layers, unlike the alloy core, allow oxygen evolution on the oxy-nitrided surface at potential of +1.6 V and at more positive potentials gradual transformation of the surfacial film into TiO 2 takes place. Secondary passivation on nitrided titanium is less efficient than that in the absence of Ti-N species.

Depth Corrosion Characteristics of Borided Layer Produced on AISI 321 Stainless Steel

“…The thickness of the layers ground off was determined from the mass loss of the examined disc electrode in relation to its initial mass, established with an accuracy of ±0.02 mg. The methodology described above [13][14][15] is called the progressive thinning method. The corrosion properties of the layers were investigated using a CHI1130A electrochemical analyzer.…”

Electrochemical Characteristics of Titanium for Dental Implants in Case of the Electroless Surface Modification

“…The field of research has been targeted by the fact that even small change in the chemical composition of the alloy significantly effect on the corrosion behavior of metals in the environment of body fluids [13], as well as the fact that the surface treatment applied to metal alloys (biomaterials, as well as other alloys) strong impact on the potentiokinetic characteristics [14,15]. To determine changes in the surface layer during phosphating the potentiokinetic polarization test in medium simulating the environment of the oral cavity (artificial saliva), profilometry research and the Vickers hardness test were carried out.…”

“…One of the methods to prevent damage to the titanium surface by abrasion is the use of appropriate technologies for surface engineering [9][10][11][12]. Preparation of the detail surface layer having improving resistance to abrasion and increases component lifetimes under operating conditions.…”

The Kinetics Of Ti-1Al-1Mn Alloy Thermal Oxidation And Charcteristic Of Oxide Layer

“…1 and 2 titanium is an active metal, but in practice, by comparing the electrochemical properties and corrosion characteristics with others metals, such as Fe, Cr, Ni, Mo, Ta, Nb and Zr, titanium proved to be the metal is not only resistant to corrosion in many natural environments, but also non-reactive with most of acids [7,9]. High affinity of titanium for oxygen makes that at room temperature on the surface creates a tight titanium oxide layer, a phenomenon occurs spontaneously and very rapidly, marked decrease in oxidation rate of the process takes place only with the saturation of the surface in oxygen.…”

“…Considerable popularity of titanium and its alloys (as well as others metallic materials) used in in prosthetics and surgery results from a very high biocompatibility with body fluids and tissues in human body, and as well as corrosion resistance to physiological media (particularly in the case of galvanic corrosion) [7,8]. The electrochemical standard potentials (E) of titanium, are [9]:…”