In this study, corrosion behavior of Cu60Zr20Ti 20 (at. %) metallic glass is investigated in acidic and neutral chloride solutions, at varying molar concentrations of chloride and also in alkaline solutions. Further, to investigate Cu60Zr 20Ti20 glassy ribbon in biological conditions, it is evaluated in phosphate buffered saline (PBS) solution. Results indicate that corrosion resistance decreases with increase in chloride concentration in case of acidic and neutral solutions. While in case of alkaline solution, corrosion resistance is found to increase with increase in pH of solution. The glassy alloy has exhibited excellent corrosion resistance in PBS medium. In order to understand the corrosion behavior, the surfaces of the samples were studied using scanning electron microscopy (SEM). SEM examination reveals pitting type of corrosion. The possible reasons for pitting corrosion in metallic glasses have been addressed in the present study. © 2013 Elsevier B.V. All rights reserved.

Budaraju Srinivasa Murty

Department of Metallurgical and Materials Engineering

BIOLOGICAL CONDITIONS

CHLORIDE CONCENTRATIONS

Chloride solutions

Corrosion behavior

CORROSION CHARACTERIZATION

EXCELLENT CORROSION RESISTANCES

MOLAR CONCENTRATION

PHOSPHATE BUFFERED SALINE SOLUTIONS

Alkalinity

Chlorine compounds

Corrosion inhibitors

Corrosion resistance

Corrosive effects

Glass

Melt spinning

Pitting

Scanning electron microscopy

X ray diffraction

Zirconium

Metallic glass

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Non-Crystalline Solids

Metallic glasses are a potential and compatible implant candidate for biomedical applications. In the present investigation, a comparative study between novel Zr55Co30Ti15 and Cu60Zr20Ti20 metallic glasses is carried out to evaluate in vitro biocompatibility using simulated body fluids. The bio-corrosion behavior of Zr- and Cu-based metallic glasses in different types of artificial body fluids such as artificial saliva solution, phosphate-buffered saline solution, artificial blood plasma solution, and Hank’s balanced saline solution is evaluated using potentiodynamic polarization studies at a constant body temperature of 310.15 K (37 °C). Surface morphology of samples after bio-corrosion experiments was observed by scanning electron microscopy. In vitro cytotoxicity test on glassy alloys were performed using human osteosarcoma cell line as per 10993-5 guidelines from International Organization for Standardization. The comparative study between Zr- and Cu-based glassy alloys provides vital information about the effect of elemental composition on biocompatibility of metallic glasses. © 2014, The Minerals, Metals & Materials Society and ASM International.

Fulltext

Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science

Bio-corrosion and Cytotoxicity Studies on Novel Zr55Co30Ti15 and Cu60Zr20Ti20 Metallic Glasses

In the present investigation, deformation behavior of melt spun glassy ribbon of Cu 60Zr 20Ti 20 has been studied using microhardness test. Further, the glassy ribbon was annealed at supercooled liquid region (ΔT x), offset of first crystallization (T x1) and offset of second crystallization temperature (T x2). X-ray diffraction and transmission electron microscopy has been used to understand the crystallization behavior of the glass and to correlate its microstructural evolution with the mechanical properties. The glassy alloy initially undergoes phase separation during annealing which transforms into a totally crystalline structure after annealing at T x2 temperature. It has been observed that at any particular load, the hardness of the alloy increases with the progress of phase separation and partial crystallization. After complete crystallization the hardness drops off. This leaves behind the scope of microstructural engineering of metallic glasses and composites for best enhancement of properties. Further the role of phase separation on the indentation behavior of this glassy alloy has been explored. The role of relaxation and crystallization on hardness and deformation behavior of glassy ribbon alloy is examined by observing the indentations under scanning electron microscopy. Results indicate that the composite structure formed during annealing at T x1 has superior hardness in comparison to other microstructures. © 2012 Elsevier B.V.

Materials Science and Engineering A

Micro indentation study on Cu 60Zr 20Ti 20 metallic glass

Electrochemical behavior of multicomponent melt spun Zr-based amorphous as well as nanocrystalline alloys have been studied in three different corrosive media (neutral NaCl, basic NaOH and acidic H2SO4 solutions). Due to the presence of strong passivating elements, (Zr and Ti) melt spun ternary alloys (Zr55Ti25Ni20) have shown complete passivation in NaCl solution even as they contain a small amount of crystallinity. Amorphous multicomponent alloys containing Cu (Zr58Cu28Al10Ti4 and Zr65Cu7.5Al7.5Ni10Pd10) show active nature in NaCl solution and this is strongly related to selective dissolution of base metal (Zr) and enrichment of Cu in the pit region. In NaOH and H2SO4 solutions, all the alloys have shown complete passivation irrespective of the alloy composition. © 2005 Elsevier Ltd. All rights reserved.

Corrosion Science

Electrochemical behavior of multicomponent amorphous and nanocrystalline Zr-based alloys in different environments

The corrosion behaviour of melt spun amorphous and nanoquasicrystalline Zr70Pd30 and Zr80Pt20 alloy ribbons has been investigated using potentiodynamic polarization study in NaCl, H 2SO4 and NaOH solutions at different concentrations. The amorphous and nanoquasicrystalline alloys show better corrosion resistance than Zr in all the solutions studied. Both the alloys are susceptible to chloride attack and pitting has been observed. Complete passivation has been observed in H2SO4, while gradual break down of passivating layer occurs in NaOH. In general, nanoquasicrystalline state in both the alloys shows better corrosion resistance than amorphous state in all the solutions studied. © 2004 Elsevier Ltd. All rights reserved.

Electrochemical behaviour of amorphous and nanoquasicrystalline Zr-Pd and Zr-Pt alloys in different environments

Intermetallics

Corrosion resistance and biocompatibility of Ni-free Zr-based bulk metallic glass for biomedical applications

Corrosion behavior and in vitro biocompatibility of Zr–Al–Co–Ag bulk metallic glasses: An experimental case study

Corrosion characterization on melt spun Cu60Zr 20Ti20 metallic glass: An experimental case study

Journal	Journal of Non-Crystalline Solids
ISSN	00223093
Open Access	No