@misc{BiedunkiewiczFigielGarbiecetal., author = {Biedunkiewicz, Anna and Figiel, Paweł and Garbiec, Dariusz and Obrosov, Aleksei and Pawlyta, Mirosława and Biedunkiewicz, Witold and Pruss, Przemysław and Rokosz, Krzysztof and Wr{\´o}bel, Rafał and Raaen, Steinar and Weiß, Sabine and Bokov, Dmitry O.}, title = {Influence of Elemental Carbon (EC) Coating Covering nc-(Ti,Mo)C Particles on the Microstructure and Properties of Titanium Matrix Composites Prepared by Reactive Spark Plasma Sintering}, series = {Materials}, volume = {14}, journal = {Materials}, number = {1}, issn = {1996-1944}, doi = {https://doi.org/10.3390/ma14010231}, abstract = {This paper describes the microstructure and properties of titanium-based composites obtained as a result of a reactive spark plasma sintering of a mixture of titanium and nanostructured (Ti,Mo)C-type carbide in a carbon shell. Composites with different ceramic addition mass percentage (10 and 20 wt \%) were produced. Effect of content of elemental carbon covering nc-(Ti,Mo)C reinforcing phase particles on the microstructure, mechanical, tribological, and corrosion properties of the titanium-based composites was investigated. The microstructural evolution, mechanical properties, and tribological behavior of the Ti + (Ti,Mo)C/C composites were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), electron backscatter diffraction analysis (EBSD), X-ray photoelectron spectroscopy (XPS), 3D confocal laser scanning microscopy, nanoindentation, and ball-on-disk wear test. Moreover, corrosion resistance in a 3.5 wt \% NaCl solution at RT were also investigated. It was found that the carbon content affected the tested properties. With the increase of carbon content from ca. 3 to 40 wt \% in the (Ti,Mo)C/C reinforcing phase, an increase in the Young's modulus, hardness, and fracture toughness of spark plasma sintered composites was observed. The results of abrasive and corrosive resistance tests were presented and compared with experimental data obtained for cp-Ti and Ti-6Al-4V alloy without the reinforcing phase. Moreover, it was found that an increase in the percentage of carbon increased the resistance to abrasive wear and to electrochemical corrosion of composites, measured by the relatively lower values of the friction coefficient and volume of wear and higher values of resistance polarization. This resistance results from the fact that a stable of TiO2 layer doped with MoO3 is formed on the surface of the composites. The results of experimental studies on the composites were compared with those obtained for cp-Ti and Ti-6Al-4V alloy without the reinforcing phase.}, language = {en} } @misc{FigielBiedunkiewiczJachetal., author = {Figiel, Paweł and Biedunkiewicz, Anna and Jach, Katarzyna and Obrosov, Aleksei and Garbiec, Dariusz and Bik, Maciej and Sitarz, Maciej and Kucia, Zofia and Pawlyta, Mirosława and Weiß, Sabine}, title = {Ti-Mo-xTiC composites manufactured by U-FAST reactive sintering}, series = {International Journal of Refractory Metals and Hard Materials}, journal = {International Journal of Refractory Metals and Hard Materials}, number = {108}, issn = {0263-4368}, doi = {10.1016/j.ijrmhm.2022.105960}, pages = {1 -- 14}, abstract = {The paper presents the characteristics of Ti-Mo-xTiC composites manufactured under experimentally selected conditions using the upgraded field-assisted sintering technique (U-FAST). Mixtures of microstructural titanium powders and nc-Ti0.9Mo0.1C/C carbide powders protected from oxidation by a carbon shell were subjected to sintering. The powders with nc-Ti0.9Mo0.1C/C contents of 10 and 20 wt\% were used. The content of carbon forming the carbon shell was approximately 3 or 40 wt\%. Composites with near full density were reinforced with titanium carbides in a Ti-Mo matrix. The composites with the highest content of reinforcing phase are characterized by the highest values of hardness, Young's modulus and wear resistance. Although the hardness of these composites is similar to that of ceramics, their nature is not brittle. Despite the high value of the Young's modulus, the addition of hard particles of the reinforcing phase to the titanium matrix significantly increases the values of the H/E ratio of the composites compared to the reference samples of cp-Ti and Ti6Al4V. A comparison of the research results for the composites with the highest share of titanium carbides showed that lowering the sintering temperature from 1300 to 1150 °C resulted in the inhibition of grain growth, a reduction in composite heterogeneity, composite roughness and hardness as well as a rise in the Young's modulus. An increase in the sintering temperature from 1150 to 1300 °C contributed to the higher high angle grain boundaries (HAGB) content.}, language = {en} }