Wyniki wyszukiwania - BazTech

1

Fe-Al based composite reinforced with ultra-fine Al2O3 oxides for high temperature applications

Kopec Mateusz, Jóźwiak Stanisław, Kowalewski Zbigniew

Journal of Theoretical and Applied Mechanics

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2021

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Vol. 59 nr 3

509--513

EN

In this paper, an Fe-Al based composite reinforced with ultra-fine Al2O3 oxides was obtained through sintering of aluminium, iron and mullite ceramic powders using self-propagated high temperature synthesis (SHS). The powder mixture with a 50%wt. content of the ceramic reinforcement was cold pressed and subsequently subjected to the sintering process in vacuum at 1200◦C for 25 minutes under external loading of 25 kN. The complex microstructure of the Fe-Al matrix reinforced with ultra-fine Al2O3 oxides was found to be desired in high temperature applications since only 3% of the relative weight gain was observed after 100 hours of annealing at 900◦C.

2

An investigation into fabrication and characterization of direct reaction synthesized Al-7079-TiC in situ metal matrix composites

Sujith S. V., Mahapatra Manas Mohan, Mulik Rahul S.

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 1

63--78

EN

The present study was attempted to highlight a novel direct reaction synthesis in which traditional casting plus rapid solidification techniques were implemented to produce Al-7079-TiC in situ composites with homogenous microstructure and improved dispersion strengthening by the reinforcing phases. Casted samples were effectively characterized by scanning electron microscopy followed by energy dispersive spectroscopy and X-ray diffraction. Ingot metallurgy showed a homogenous distribution of TiC particles inside the grain. This particle behavior acted as an excellent nucleation sites for the Al dendrites to grow unvaryingly. TiC reinforcements have semi coherent relationship with α-Al matrix. It was observed that eutectic boundary includes the second phases based on η (MgZn2) and Mg(Zn, Cu, Al)2. Almost 90% of the in situ reinforced TiC were homogenously distributed along the center of the grain. Thermal history conditions have shown an exothermic behavior during casting. Experimental results revealed the evolution of TiC particles in super-heated melt region, i.e. dissolution of titanium continued by reaction of titanium with diffused carbon in the Al matrix to form TiC particles. Further they acted as nucleation sites for the α-Al dendrites to grow homogenously. This study presents optimum process temperature for the Al-TiC in situ synthesis.

3

The influence of heating rate during sintering on mechanical properties of Fe40Al sinters at room temperature

Siemiaszko D., Nowakowska I., Komorek Z.

Inżynieria Materiałowa

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2016

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Vol. 37, nr 5

267--271

EN

The results of a uniaxial compression test of Fe40Al (at. %) sintered powders are presented. Compression yield stress Rc0.2, ultimate strength Rcm, permanent deformation, and true compression strength at the maximum force point were determined. All Fe40Al sinters behaved like a plastic material; they were not brittle, and the sample after the compression test did not fall apart and was barrel-shaped. Observations of the microstructure revealed plastically-deformed grains. The obtained sinters were characterized by very high ultimate compressive strength (ok. 2700÷2800 MPa) and low yield stress (Rc0.2 approx. 280 MPa). This paper presents also XRD analyses, microstructure, and density of Fe40Al sinters.

PL

Podstawowym celem pracy było zbadanie wpływu szybkości nagrzewania podczas spiekania na właściwości mechaniczne spieków Fe40Al. W pracy zaprezentowano wyniki analizy dyfrakcji rentgenowskiej, pomiary gęstości, twardości sposobem Vickersa (HV0,5), a także właściwości wytrzymałościowe uzyskane w próbie ściskania.

4

Laser remelting of Al-Fe-TiO3 composite powder incorporated in a aluminium matrix

Grabowski A., Formanek B., Sozańska M., Nowak M.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 18, nr 1-2

95--98

EN

Purpose: This paper describes the process of a laser beam effect on aluminium composite powders with iron titanium oxide. Design/methodology/approach: The powder was obtained by mechanical agglomeration. The fraction of oxide phases reinforcing the aluminium matrix amounted to 30 wt.%. It was assumed in the material and technological conception that the structure of the powders would change and intermetallic phases as well as aluminium oxide would be formed in aluminium matrix. The structure of the powders and of the connections with the metallic matrix was analyzed by optics and scanning microscopy methods, and X-ray microanalysis. Findings: The correlation of the structure of powders remelted with the substrate was determined, depending on the laser beam intensity. There were aluminium oxide and respective intermetallic phases from the Al-Fe-Ti system present in the eutectic, inhomogeneous structures. Research limitations/implications: The interaction of high energetic laser beam with the reactive composite powders is a very complex process. Laser parameters process such as density of laser energy the time of interactions could be optimized to o find the operational laser parameter window for satisfactory remelting of the AlFeTiO3 composite. Originality/value: The research results characterize the multiphase ceramic matrix composite structure of connections formed by the interaction of high intensity CO2 laser beam with the reactive powder.