To Investigate the Role of Thermal Spray Coating in Biomaterials for Combating the Rate of Corrosion In-Vitro Sarbjit Kaur Research Scholar IKGPTU Kapurthala Niraj Bala Mechanical Engg. Deptt. BBSBEC, Fatehgarh Sahib, India Charu Khosla Associate Prof. Deptt. Applied Sciences Chitkara University, Banur Rohit Upadhyaya Birla institute of Tech. and Sci. Pilani Abstract—A bio-implant is a medical device made to replace and act as a missing biological structure These implants are broadly used in various biomedical applications such as surgical implants, including joints, total hips, knees and dentures. The aim of the present study is to evaluate in-vitro corrosion behavior of uncoated as well as thermal sprayed hydroxyapatite (HAP) coated 316LStainless steel. The economical technique for reducing the rate of corrosion and improves the bioactivity of these existing materials is considered to be Surface modification. Hydroxyapatite (HAP) coatings are used on these alloys to improve the characteristics such as biocompatibility, bone bonding ability and also reduces the toxic effect of bioimplants on living organism. The coating was characterized by electrochemical techniques and SEM/EDS. The results show that after the deposition of the HAP coating, the corrosion resistance of the steel increases. This property of enhanced corrosion resistance is used as a promising technology in biomaterial research and for many clinical applications. Keywords: 316L SS, HAP, in-vitro, corrosion, biocompatibility. I. INTRODUCTION Biomaterials are used to make devices to implant a part or a function of the body in safe, reliably economically, and physiologically acceptable manner. A huge variety of such devices and materials are used in the treatment of disease or injury including oral and dental implants. Material of medical instrument, coating, and implant must be corrosion resistant and should tolerate the aggressiveness of biological fluids (blood, urine, lymph, gastric juice, etc.). Long-term exposure of implant material to living tissue should not exert toxic impact. No toxic effect should be observed during even short-term contact of medical instrument with living tissues. Medical instruments should not induce carcinogenesis, mutagenesis, or cytotoxicity during prolonged exposure. The metals or their alloys are not viable to be directly implanted in human body due to corrosion. Due to secretion of some metallic ions (like Fe +2 ) in vicinity of these organs, it may lead to fibrosis, which is not suitable for body. So the base metal should be coated with materials whose composition be quite similar to that of bones and are biocompatible which may lead to the further growth and development of bones [1]. The coating material should be bioactive and bioresorable. Hydroxyapatite or Calcium phosphate are frequently used for coating. HAP is commonly used as the coating material because it shows bioactivity, bioresorbility, biocompatibility and also the ossoinduction [2]. HAP coating on metallic alloys enhances the bone bonding ability and also improves the biocompatibility and reduces the toxic effect of bioimplants on living organism. The implanted material is accepted to withstand applied physiological forces without any major change. In addition these coatings leads to biocompatibility, provides local source of calcium and phosphate ions required for bone cell to grow [3,4]. Plasma spray technique is generally used for deposition of HAP as a bioceramic but due to the inherent high temperature in the plasma, detrimental effects such as evaporation, phase altercation, residual stress, debonding etc., commonly occur in these coatings. Present study presents a novel approach to deposit HAP at a temperature below its melting point using thermal spray technique. The phase composition of the HAP deposited by the thermal process is identical to that of the powder has been been analysed by SEM/EDS. The HAP Coatings deposited using this process hold enormous potential for improving ossoinduction of bones in wide range of dental and orthopedic implants with technological basis. Hydroxyapatite (Ca10(PO4)6(OH)2, has been widely used in dental and orthopedic implants, due to its structural and chemical similarity with bone minerals [5-7]. Nowadays, in order to increase the biocompatibility and to improve the performance, surface modification of implants has been carried out successfully. Biological response of the host depends on the primary interactions of biomaterials implanted at biological molecular surfaces. Therefore, the surface morphology influence the compatibility as well as the optimal performance of the implant in body [8]. International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Published by, www.ijert.org ESDST - 2017 Conference Proceedings Volume 5, Issue 05 Special Issue - 2017