Introduction

In recent decades body implants has became really important using different types of alloys. Implants are fabricated from a wide variety of materials, including metals, polymers, ceramics and their composites. Among these materials, metals are an important group. Metal implants were first introduced by Lane in 1895 since he discovered metal plate for bone fracture fixation [1]. One of the common alloys known in implant surgery is CoCrMo alloys and this because of its high biocompatibility, high wear and corrosion resistance. Cobalt chrome alloys are used widely for medical prosthesis such as hip and knee replacements, dental devices and support structures for heart valves because they have a great biocompatibility and spontaneous chromites formation of a passive layer which provides the material high corrosion resistance. In the early progress, metal implants had several issues including corrosion and insufficient strength problems [2].