@misc{FellahHezilBourasetal., author = {Fellah, Mamoun and Hezil, Naouel and Bouras, Dikra and Obrosov, Aleksei and Samad, Mohammed Abdul and Montagne, Alex and Abd-Elmonem, Assmaa and Din, Sayed M El and Weiß, Sabine}, title = {Structural, mechanical and tribological performance of a nano structured biomaterial Co-Cr-Mo alloy synthesized via mechanical alloying}, series = {Journal of Materials Research and Technology}, volume = {25}, journal = {Journal of Materials Research and Technology}, issn = {2214-0697}, doi = {10.1016/j.jmrt.2023.06.031}, pages = {2152 -- 2165}, abstract = {The influence of milling time on the tribological behavior of a Co-Cr-Mo alloy designed for biomedical applications, synthesized via mechanical alloying is investigated. Elemental Co, Cr and Mo powders are milled using different milling times (2, 6, 12 and 18 h) in a high-energy ball mill. The resulting powders were subjected to cold uniaxial and hot isostatic pressing respectively, followed by sintering to obtain cylindrical samples, which were evaluated for their structural, mechanical and the wear behavior. Results showed that the grain and crystallite sizes of the powders decreased with increasing milling time, reaching low values of <10 μm and 32 μm respectively, at higher milling times. Furthermore, the wear rates and the coefficients of friction were lower, at higher milling times due to high densities (96\%), and higher elasto-plastic resistance, as presented by the H/E and H3/E2 values of 0.026 and 0.0021 GPa, respectively. Increased milling time enables the refinement of grains and reduction in porosity in the Co-Cr-Mo alloy, which in turn increases the alloy's elasto-plastic resistance and enhances its wear resistance.}, language = {en} } @misc{HamadiFellahHeziletal., author = {Hamadi, Fouzia and Fellah, Mamoun and Hezil, Naouel and Bouras, Dikra and Laouini, Salah Eddine and Montagne, Alex and Khalifa, Hamiden Abd El-Wahed and Obrosov, Aleksei and El-Hiti, Gamal A. and Yadav, Krishna Kumar}, title = {Effect of milling time on structural, physical and tribological behavior of a newly developed Ti-Nb-Zr alloy for biomedical applications}, series = {Advanced Powder Technology}, volume = {35}, journal = {Advanced Powder Technology}, number = {1}, issn = {1568-5527}, doi = {https://doi.org/10.1016/j.apt.2023.104306}, abstract = {Titanium (Ti)-based alloys with only a β-phase have attracted academic and industrial interest for orthopedic application, due to their close properties to those of tissues. The current study aims to investigate the effect of milling time (2 h, 6 h, 12 h and 18 h) on the nanostructured ternary alloy Ti-25Nb-25Zr prepared by high energy milling, on its structural, physical and tribological behaviors. The alloys' characteristics such as relative density/porosity, surface roughness, were evaluated using XRD, SEM, surface profilometry, and microdurometer, respectively. The tribological characterization was done using an oscillating tribometer under wet conditions, simulating the human body environment. Results showed that the crystallite and mean pore size reduced with increasing milling time, with the smallest values of 26 nm and 40 µm, respectively after 18 h. Structural characterization shows that the amount of the β-Ti phase increased with increasing milling time, resulting in spherical morphology and texturing of the synthesized alloys. The milled alloys' structural evolution and morphological changes were sensitive to their milling times. Also, the relative density, Young's modulus and hardness, increased due to grain size decreased with increasing milling time. Tribological results showed that the effect of milling has a significant effect on both nanomaterial formation and friction-wear behavior of the alloys. The results showed that, friction coefficient and wear rate significantly decreased due to the increased formation of protective films such as TiO2, Nb2O5 and ZrO2 phases. The wear mechanism of the Ti-25Zr-25Nb system was dominated by abrasion wear accompanied by adhesion wear.}, language = {en} }