Investigation of the micromachinability of cobalt chrome alloys made by additive manufacturing

With the development of technology, the use of additive manufacturing in many different fields, especially aviation, automotive and biomedical, is increasing in order to produce materials in a flexible and efficient way. The most important feature that distinguishes additive manufacturing from traditional manufacturing in the biomedical field is that it allows the production of devices by the patient's condition and complex anatomical regions of the body. For this reason, examining the manufacturing process with additive manufacturing for the production of medical devices is an important research topic to define an optimized manufacturing system for these applications. Additive manufacturing provides the formation of the desired part by melting the metal powder layer by layer with a laser. As a natural consequence of additive manufacturing, there are problems with dimensional accuracy, surface quality, and hardness. Additive manufacturing has disadvantages, especially when high precision is required or parts need functional micro-scale features. Therefore, even if the part is created by additive manufacturing, micro-machining can be used to produce special properties in this process chain, improving end part characteristics such as roughness or surface mechanical properties. Micro milling has an important place in this process chain due to the improvement in the properties of the final part. CoCr alloys have been recognized as effective biomaterials due to their excellent mechanical properties, high corrosion resistance, and high wear resistance. In this study, CoCr alloy samples, which we will micro-machining, are produced using Selective Laser Melting (SLM) and casting methods. Limited research has been reported on the fundamental mechanisms involved in the micro-cutting of Co-Cr alloys produced by additive manufacturing. For this reason, it is tried to present basic information about the cutting mechanisms in the micromachining of Co-Cr alloys. In addition, production optimization was determined by comparing and interpreting the structural changes that will occur in different parameters, factors affecting production continuity such as temperature, stress, surface quality, burr and chip formation. The temperatures and Von mises stresses occurring during the micro-milling experiment were analyzed by the finite element method and compared with the experimental results. Keywords: Micro Milling,CoCr alloys, Additive Manufacturing, Selective Laser Melting, Finite Element Method