Bio-Compatible Processing of LENS TM Deposited Co-Cr-W alloy for Medical Applications Ganzi Suresh 1* ; K L Narayana 2 ; M. Kedar Mallik 3 *1, 2 Department of Mechanical Engineering Koneru Lakshmaiah Education Foundation, Guntur, India – 522502 3 Vasireddy Venkatadri Institute of Technology, Guntur, India – 522508 *Corresponding author E-mail: ganzi.suresh@kluniversity.in Abstract Developing a Medicinal implants or devices is a challenging task for the researchers, right from the selection of materials, design, biocompatibility and implantation to the host tissue. At every stage it requires proper care in processing of medical implants. In recent years the demand for medical implants had grown rapidly due to the awareness in the society. Major share of implants is used by younger people as they are active in sports, motor vehicle accidents leads to facture. Even older people also preferring to implants for ease of living. The commonly used implants are, prosthetic joints, knee replacement, dental, maxillofacial reconstructions etc.There is huge demand for the medical implants in coming years, presently a few bio-materials available for implant devices such as Ti-alloys, Stainless steel and Co- Cr-Mo alloys. There a scope to the researchers to develop a new alloy that are bio-compatible in nature and bring down the cost of the implant procedure to the needed patients. In this context additive manufacturing (AM) is an advanced manufacturing technology emerging as prominent technique in medical fields. Laser Engineered Net Shaping TM (LENS) is one such metal additive technique which provides fabrication of parts with the help of laser power, melts the powder alloy completely and builds parts layer by layer directly from the CAD model. In the present study, samples are fabricated from LENS process and carried the In-Vitro and In -Vivo bio-compatible tests as cytotoxicity and sub chronic toxicity to verify the toxicants release and their sustainability as the medical implants by the LENS deposited Co-Cr-W alloy samples. From the studies it is observed that the alloy samples show acceptable result. MTT assay demonstrate that cell viability is better in Osteoblast cells compared to the Fibroblast cells. Osteoblast cells show slightly more viable to the cell treatment on the samples during the experimental period. Sub chronic toxicity conclude that LENS deposited Co-Cr-W alloy is not toxic in all the rats studied herein and did not produce any toxic signs or evident symptoms. LENS deposited Co-Cr-W alloy did not cause any lethality or produce any relative body organs weight and haematological studies didn’t show adverse effects. Key Words: LENS TM ; bio-compatibility; cytotoxicity; sub chronic toxicity; medical implants; Co-Cr-W alloys. 1. Introduction Economic status of the people had increased since globalization; the quality of living life of people has changed, awareness on health consciousness had increased in developed and developing nations across the globe. Activities of peoples like sports, driving vehicles, defence etc. are resulting number of accidents. Increase in age of elderly people their potential to bear weight of body had decreased in bones, joints. Due to advancements in medical science increased since there is demand for medical implants to restore the damaged parts. Most commonly used medical implants in human body are maxillofacial reconstruction, cranial repairs, dental implants, bone fracture fixations, load bearing implants, prosthetic joints[1]. Medical implants should possess high mechanical strength, wear and corrosive resistance and bio-compatible to human body[2]. There are few materials available for biomedical applications. Materials such as Ti alloy, stainless steel, Ni based alloys; tantalum alloys and cobalt based alloys are commonly used for medical implants and medical devices. There is huge demand in medical industry for advanced materials for medical applications. An extensive research is to be carried out in the development of biomaterials for implants and devices. The use of Ni based alloys has been decreased due to its allergic reactions and may cause cancer tumours in some patients[3]. It is good to avoid Nickel in all medical usage. Medical grade materials should be biocompatible and should not get any chemical reaction with the body fluids while inserted in to human body. They should exhibit good mechanical properties such corrosion resistance, wear resistance and mechanical strength [4]. Commonly used alloys in medical use are Ti alloy (Ti-6Al-4V)[5], stainless steel[6], tantalum alloys[7] which are commercially developed so for. There is scope for development of new alloys in medical applications. Recently Cobalt based alloys gaining much importance in development of medical implants such as orthopaedic, load bearing implants, knee joints, prosthetics and dental applications. Cobalt alloys are high resistance to corrosion, excellent mechanical properties and bio-compatible. Commercially available cobalt alloys are Co-Cr-Mo and Co-Cr-W alloys. Fabrication of medical implants in conventional manufacturing process is complex to handle the multiple tasks like melting, tooling, milling etc. It is also difficult to prepare the moulds for International Journal of Engineering & Technology, 7 (2.20) (2018) 362 - 366 International Journal of Engineering & Technology Website: www.sciencepubco.com/index.php/IJET Research paper