Tribological properties of the Fe-Al intermetallic alloys after annealing

In paper researching results of tribological proprieties Fe3Al intermetallic alloys after annealing are presented. Studies were conducted in the following environments: a water; an air and oil. For investigation purposes the tribotester pin-on-disk type with the contrsample made of steel 40H quenched and tempered was used. Tests were carried out with the following process parameters: pressure p = 2MPa and linear velocity (circuital) V = 0.46m/s. It was noted, that intermetallic samples with the small distinction in chemical compositions, annealed at different temperatures showed a large difference in the quantity of material loss in the all tested environments. Appropriately selected parameters of the intermetallic alloys annealing, provide their greater resistance to abrasion in the air and oil environments than in the case of steel

The fatigue properties and fracture process of ion-nitrided steel 50H21G9N4

In the paper the fundamental fatigue properties of the valve steel 50H21G9N4 in delivery state and with modified after ionic nitrided surface layer are investigated. The fatigue strength of test pieces of such materials under cyclic loading are determine and their fracture processes are describe

Relatório de estágio em farmácia comunitária

Relatório de estágio realizado no âmbito do Mestrado Integrado em Ciências Farmacêuticas, apresentado à Faculdade de Farmácia da Universidade de Coimbr

The Influence of Top Layer State on Selected Properties of the Machines Alloy Ti-6Al-3Mo-2Cr Elements

Przedstawiono wyniki badań mikrostruktury i wybranych właściwości mechanicznych stopu tytanu Ti-6Al-3Mo-2Cr poddanej procesom azotowania. Zbadano wpływ stanu powierzchni oraz sposobu azotowania na wybrane właściwości mechaniczne badanego stopu. Stwierdzono, że poziom wytrzymałości zmęczeniowej stopu tytanu Ti-6Al-3Mo-2Cr, w bardzo istotnym stopniu jest uzależniony od stanu warstwy wierzchniej próbek poddanych badaniom (elementów maszyn).This research was concerned with the investigation of microstructure and selected mechanical properties of titanium alloy Ti-6Al-3Mo-2Cr after plasma nitriding processes. The influence of surface state and the nitriding method on selected mechanical properties of examined alloy was investigated. It was found that that the level of fatigue strength of titanium alloy Ti-6Al-3Mo-2Cr depends significantly on top layer state of examined samples (machines' elements)

Influence of annealing time and temperature on the Fe3Al intermetallic alloys microstructure modification

There is an industry interesting in intermetallic alloys in recent years. There are widely possibilities to adopt this kind of materials for structural units. More expensive materials can be replaced by them. A property which limits their wider application is the low plasticity at environment and elevated temperatures. In paper the results of the thermal microstructure modification are shown. To this end, the influence of annealing time and temperature on the intermetallic phase Fe3Al grain size was investigated. The impact of these factors on micro-hardness was examined as well. It was found that these operations cause the grain size reduction and the micro-hardness decrease

Methodology of the vertical axis wind turbines location fields researching

W pracy poruszono problematykę integracji energetyki wiatrowej ze środowiskiem. Przedyskutowano plusy i minusy pozyskiwania energii z wykorzystaniem odnawialnych źródeł energii. Zasygnalizowano możliwości rozwoju turbin wiatrowych o pionowej osi obrotu przeznaczonych dla odbiorców o stosunkowo niewielkim zapotrzebowaniu mocy - do około 1,5 kW. Zaproponowano nowe autorskie rozwiązania konstrukcji masztów (typu "F", "2F" oraz "F/2F") przeznaczonych do mocowania wirników turbin wiatrowych. Podkreślono przy tym, że zaproponowane rozwiązanie bardzo dobrze wkomponowuje się w infrastrukturę i architekturę występującą na danym terenie. Według przeprowadzonych przez autorów badań własnych, wykazano, że dla okolic Białegostoku (Nowosiółki k. Krypna) prędkość wiatru zmienia się stosunkowo dużym przedziale w zależności od czasu pomiaru. Skutkuje to odpowiednio zmianami pozyskiwanych chwilowych mocy przez turbinę. Analiza wyników badań własnych wykazała również, że w danych warunkach terenowych występują stosunkowo duże różnice potencjalnego pozyskiwania mocy przez turbinę w poszczególnych miesiącach.This work touches the problems connected with the integration of wind energetic with the environment. There were discussed the advantages and disadvantages of the gain of energy with the usage of the renewable sources of energy. There were represented the opportunities of the development of wind turbines with the vertical turn axle appropriated for the receivers with about 1,5 kW. The author proposes the new solution of the construction of masts (of "F", "2F" and "F/2F" types) appropriated to the fixing of runners of the wind turbines. It was emphasized, that the proposed solution introduces in the infrastructure and architecture of the local territory. In according with the own author's searches it has been indicated that the speed of wind changing in the relatively large section is depended on the time of measurement for the surrounding of Białystok (Nowosiolki near Krypno). It causes the changes of the gained transitory power of turbine. The analysis of the results has also showed that in local conditions there are relatively big differences of the potential gaining of power by turbine during several months