Comparative study of the imposed effects by the process of cryogenic grinding and high energy milling of titanium

Abstract

This work was carried out in order to compare the microstructural and compositional characteristics given as result of two ground processes on the pure titanium powder. The ground processes evaluated were: cryogenic in "atritor" grinder and high energy in "spex" grinder. The microstructural characteristics evaluated by means of X-Rays diffraction and electronic microscope were the size and morfology of the particles and the size of the grain. Aditionally, powder chemical composition after each ground process, was evaluated by means of spectroscopy. Experimental results demonstrated that less than 20 nm powder nanocrystalline titanium can be prepared by means of cryogenic ground. Durin the ground, particle size initially increases from original 55 micrometers to a maximum of 125 micrometers after two hours of ground, and decreases to 44 micrometers after the eight hours. Both the the particle and the grain size decrease as the balls-grain ration (RBP) increases. The oxygen, nitrogen and iron levels are also increased in relation to the ground time.