The Investigations on Formability of Tantalum RO5200 Thin Foils: Bio-Material.

Abstract

Tantalum RO5200 (TaRO5200) is an excellent and new emerging Bio-material with wide applications. The most important property of TaRO5200 is Osseointegration which helps in integration of direct structural and functional connection between living bone and the surface. The process of forming in at actual is a plastic deformation where in the material is transforming in permanently is some shape without occurrence of any type of defect of failure. Few different types of failure enlisted are local necking, wrinkling, earing etc. In recent days transforming from macro level to micro level is now trending part of life. The most difficult part in moving towards micro level forming which means forming sheets under 100 microns thickness, is control over process. Hence this gives significance and rise for the investigations over forming at micro level and prediction of mechanical and formability properties at micro level. This research work posited in this paper focusses on the plotting of Forming limit curve (FLC) which is one of the methods to investigate formability of ultra-thin foil of TaRO5200 with sheet thickness 80 microns (μm). The experiments performed for FLC plotting were based on the Nakkajima test following the ASTM 2218-14 standards. The FLCs are plotted experimentally and via numerical simulation as well which in comparison shows a good agreement. The variance obtained between experimental and numerical simulation is up to 15%. Which in another words can be stated as numerical simulation is 15% safer in design than the experimental work. The novelty of the work lies in testing of the bio material and defining FLC by performing experiments via newly designed tool for the specific sheet thickness of 80 μm following the ASTM standards. Microstructural study is also performed on the specimen prior and after forming test to analyse and understand the physics along with mechanism of the material in test. The material behaviour is also explained in the microstructural study section.