Development and surface improvement of FDM pattern based investment casting of biomedical implants: A state of art review

Fused deposition modelling (FDM) is one of the additive manufacturing (AM) techniques, emerging as a favorable technique in different industries including medicine. The most distinctive purpose of AM in medical industries is to design and produce medical devices, instrumentation and implants. In association with other techniques, it leads to improvement in services offered to society for e.g., in combination with investment casting (IC) process it can produce bio-implants with complex geometries and features at a comparatively less cost and in a less interval of time. While, IC is also a very promising technique to produce net-shape parts with high accuracy and surface finish, however the surface finish of the final casting greatly depends upon the finishing quality of FDM pattern. But, due to inherent limitations of the process, FDM patterns face surface roughness issues, therefore the need of processing of patterns before/during the production or after the fabrication of the pattern, arises. So, this paper will spot a light on development of casted implants and some surface improvement techniques (pre-processing and post-processing) which can be implemented on patterns to enhance its surface properties and their effects will be studied on the pattern as well as casting. It will also focus on the implant materials, production details of implants,and their corrosion studies.