Electrochemical Behavior of Fe3Al Modified with Ni in Hank´s Solution
C.D Arrieta-Gonzalez1,2, J. Porcayo-Calderon3,*, V.M. Salinas-Bravo3, J.G. Gonzalez-Rodriguez4, J.G. Chacon-Nava1
Centro de Investigación en Materiales Avanzados, Miguel de Cervantes 120,31109-Chihuahua, Chihuahua, MEXICO. 2 Instituto Tecnológico de Zacatepec, Depto. De Ingeniería Química y Bioquímica, Av. Instituto Tecnológico 27, Zacatepec, Morelos, MEXICO 3 Instituto de Investigaciones Eléctricas, Gerencia de Materiales y Procesos Químicos, Av. Reforma 113, Col. Palmira, 62490-Cuernavaca, Morelos, MEXICO. 4 Centro de Investigación en Ingeniería y Ciencias Aplicadas-UAEM, Av.Universidad 1001, Col. Chamilpa, 62210-Cuernavaca, Morelos, MEXICO. * E-mail: email@example.com Received: 1 July 2011 / Accepted: 12 August 2011 / Published: 1 September 2011 An investigation about the corrosion resistance of Fe3Al-type intermetallic alloys in Hank´s solution was carried out via electrochemical techniques. The Fe3Al intermetallic alloy was modified with additions of Ni and evaluated inthe as cast and thermal treated conditions. For comparison, Titanium and 316-L stainless steel were also evaluated. For evaluation purposes, electrochemical techniques included potentiodynamic polarization curves, open circuit potential measurements, linear polarization resistance curves and cyclic polarization curves were employed. Results shown that the 316-L stainless steel and titanium are thematerials with greater corrosion resistance in chloride-rich environments showing an active-passive behavior and are susceptible to pitting corrosion. Compared to 316-L SS and Titanium, intermetallic Fe3Al alloys had greater susceptibility to pitting corrosion. Ni addition changed the corrosion potential of the intermetallic base Fe3Al to more noble values. Ni addition and thermal treatmentimproved the corrosion resistance of Fe3Al-base alloy owing to an increased stability of the passive layer.
Keywords: intermetallics, corrosion, Fe3Al, chlorides, biomaterials 1. INTRODUCTION Biomaterials are materials used in the manufacture of devices that interact with biological systems and coexist for a long period of service with minimal failure. They are widely used for repairing orreplacement of components of the tissue-skeletal system such as bones, joints and teeth.
Int. J. Electrochem. Sci., Vol. 6, 2011 .
The fundamental requirement of a biomaterial is that material and body tissue environment can coexist without any undesirable or inappropriate effect on each other. Biocompatibility is an essential requirement for any biomaterial. Medical devices made frombiomaterials are hip replacements, heart valves, neurological prostheses and systems for drug delivery. Devices placed inside the body for a defined time are known as implants, and those placed permanently as a prosthesis . Orthopedic implants have improved the quality of life for millions of people. The clinical goal is to relieve pain and increase ease of movement in joints. The engineering goalis to provide the minimum physiological strain. Integrity and functionality of bone and prosthetic materials has to be maintained for a period of long service. Suitable materials for implants are those tolerated by the body and they should be able to withstand cyclic loading in the aggressive environment of the body . The fundamental criterion of a biomaterial is its biocompatibility. Metalsand alloys have been widely used as implants and they provide the mechanical strength and corrosion resistance required. Metallic implants are generally made of one of these three types of materials: austenitic stainless steel, chromium-cobalt alloys, and titanium and its alloys . In particular, the 316-L stainless steel is used as an implant material because of a favorable combination of...