PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 8

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available remote Problems fabricating cast magnesium matrix composites with aluminosilicate cenospheres
Kamieniak J., Braszczyńska-Malik K. N.
Composites Theory and Practice
|
2014
|
R. 14, nr 4
214--218
EN
The problems with fabricating magnesium matrix composites with aluminosilicate cenospheres were demonstrated. Two casting methods, typical stir-casting and vacuum casting processes were chosen to obtain AZ91 magnesium matrix composites with hollow cenospheres 63÷125 μm in diameter. In both methods, violent reactions between the components precluded the fabrication of the desired composites with undestroyed cenospheres. The main reaction products were oxides and an Mg2Si compound. The creation of a Ni-P coating on aluminosilicate cenospheres (by electroless plating method) in connection with the application of the vacuum casting process allowed the authors to obtain composites with cenospheres not filled by the matrix alloy. The proposed solution contributed to the fabrication of composites characterized by about 60 vol.% uniformly distributed cenospheres and a final material density equal to about 1.16 g/cm3.
PL
Przedstawiono problem z wytwarzaniem kompozytów magnezowych z mikrosferami glinokrzemianowymi. Zastosowano dwie metody odlewnicze, tj. mechanicznego mieszania oraz infiltracji podciśnieniowej, do otrzymania kompozytów na osnowie stopu magnezu AZ91 z pustymi wewnętrznie mikrosferami o średnicy 63÷125 μm. W obu metodach gwałtowne reakcje pomiędzy komponentami uniemożliwiały wytworzenie pożądanych kompozytów z nieuszkodzonymi mikrosferami. Głównymi produktami reakcji były tlenki oraz związek Mg2Si. Wytworzenie warstwy Ni-P na mikrosferach glinokrzemianowych (metodą bezprądowego osadzania) w połączeniu z metodą infiltracji podciśnieniowej pozwoliło na otrzymanie kompozytów z mikrosferami niewypełnionymi stopem osnowy. Proponowane rozwiązanie pozwoliło na wytworzenie kompozytów charakteryzujących się równomiernym rozmieszeniem 60% obj. mikrosfer i końcową gęstością materiału równą około 1,16 g/cm3.
2
Content available remote Microstructural stability of Mg-5Al-0.4Mn-3RE alloy during annealing
Żydek A., Kamieniak J., Braszczyńska-Malik K. N.
Archives of Foundry Engineering
|
2011
|
Vol. 11, iss. 4
163-166
EN
As-cast Mg-5Al-0.4Mn-3RE magnesium alloy was prepared successfully. The microstructure and microstructural stability at 473K were investigated by light microscopy and X-ray diffraction (XRD).The results revealed that the as-cast Mg-5Al-0.4Mn-3RE alloy consists of \delta - Mg matrix, eutectic \delta + \gamma (where \gamma is Mg17Al12), Al11RE3 precipitates and Al10RE2Mn7 phase. After annealing at 473K for 100h and annealing at 473K for 100h after compression with a stress 280 MPa needle shape particles of Al11RE3 remained unchanged due to their relatively high melting point.
3
Content available Influence of process temperature on AZ91 matrix microstructure of composites with aluminosilicate glass cenospheres
Kamieniak J., Żydek A., Braszczyńska-Malik K. N.
Archives of Foundry Engineering
|
2011
|
Vol. 11, iss. 3 spec.
107--110
EN
AZ91 magnesium alloy matrix composites with aluminosilicate glass cenospheres were fabricated successfully by the pressure infiltration method. Different parameters of the fabrication process, such as temperature of the mould and temperature of cenospheres were used. Influence of the temperature variation of particular parameters on the microstructure has been investigated. The microstructure of AZ91 magnesium alloy and fabricated composites have been investigated by light microscopy (LM) and scanning electron microscopy (SEM). The results revealed that AZ91 magnesium alloy consists of α-Mg matrix and eutectic α-Mg17Al12 and a small amount of discontinuous precipitates of γ phase. The microstructure of matrix AZ91 in fabricated composites is characterized also by the presence of α-Mg matrix and eutectic α-Mg17Al12. However, in the composite fabricated by using the mould heated to 500 °C more discontinuous precipitates of γ phase were observed.
4
Content available remote Evolution of Mg-5Al-0.4Mn microstructure after rare earth elements addition
Żydek A., Kamieniak J., Braszczyńska-Malik K. N.
Archives of Foundry Engineering
|
2011
|
Vol. 11, iss. 2
157-160
EN
Mg-5Al-0.4Mn-xRE (x = 0, 1, 2, 3 wt.%) magnesium alloys were prepared successfully by casting method. The microstructure was investigated by light microscopy. The influence of rare earth (RE) elements on the area fraction of eutectic was analysed. The obtained results revealed that the as-cast Mg-5Al-0.4Mn alloy consist of \alfa - Mg matrix and eutectic \alfa + \gamma (where \gamma is Mg17Al12). However, while rare earth elements were added to the Mg-Al type alloy, Al11RE3 precipitates were formed. The amount of the Al11RE3 precipitates increased with increasing addition of RE, but the amount of \gamma - Mg17Al12 decreased.
5
Content available Aluminosilcate glass cenospheres as a component of cast magnesium matrix composites
Kamieniak J., Żydek A., Braszczyńska-Malik K. N.
Archives of Foundry Engineering
|
2011
|
Vol. 11, iss. 2 spec.
109--112
EN
The main characteristic of aluminosilicate glass cenospheres and their possible use as a component of magnesium matrix composites were presented. The results revealed that particular parts of cenospheres differ insignificantly from each other and it depends on which power plant cenospheres come from. The characteristic of cenospheres concerned their structure and phase composition and dimensions such as: wall thickness and size of pores occurring in walls, depending on cenospheres origin. Thickness of cenospheres walls and pore size were measured by using ImageJ computer software. The structure of aluminosilicate glass cenospheres and their phase composition have been investigated by scanning electron microscopy and X-ray diffraction (XRD). The possibility of cenospheres utilization in the fabrication of magnesium matrix composites was presented on the example of AZ91 magnesium alloy composite with fly ash cenospheres. Composite was fabricated by pressure infiltration method.
6
Content available remote The effect of rare earth elements on the microstructure of as-cast AM50 alloy
Żydek A., Kamieniak J., Braszczyńska-Malik K. N.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 1 spec.
147--150
EN
As-cast Mg-5Al-0.4Mn-xRE (x = 0, 1, 2 wt.%) magnesium alloys were prepared successfully and influence of rare earth (RE) elements on the microstructure has been investigated by light microscopy and X-ray diffraction (XRD). The results revealed that the as-cast Mg-5Al-0.4Mn alloy consist of α - Mg matrix and eutectic α + γ (where γ is Mg17Al12). With the addition of rare earth elements Al11RE3 precipitates were formed. The amount of the Al11RE3 precipitates increased with increasing addition of RE, but the amount of γ - Mg17Al12 decreased. Additionally, in alloys with rare earth elements no aluminium-manganese precipitates were observed, instead of that ternary intermetallic compound Al10RE2Mn7 was formed.
7
Content available remote Analysis of heavy alloying elements segregation in gravity cast experimental Mg-Al-Zn-RE alloy
Żydek A., Polis-Olejniczak A., Malik M. A., Kamieniak J., Braszczyńska-Malik K. N.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 1
217-220
EN
Microstructure of experimental AZ91 alloy with an addition of rare earth elements (RE) at a level of 4 wt.% was examined by means of light microscopy. The investigated AZ91 + 4 wt.% RE alloy was fabricated by adding cerium rich mish metal to molten commercial AZ91 alloy. In the microstructure of the resulting alloy, besides [alpha] solid solution, [alpha] + [gamma] eutectic and discontinuous precipitates of [gamma] phase, also the Al_11RE_3 phase with needle-like morphology and the polygonal Al_10RE_2Mn_7 phase were revealed. No segregation of rare earth elements was found in the investigated gravity cast alloy, which was confirmed by statistical analysis of cerium concentrations in selected parts of the cast. Similar results were obtained for manganese. Ce and Mn concentrations were determined by a spectrophotometric method.
8
Content available remote Non-standard heat treatment of cast AZ91 magnesium alloy
Braszczyńska-Malik K. N., Kamieniak J.
Archives of Foundry Engineering
|
2008
|
Vol. 8, iss. 1 spec.
31--34
EN
Results of microstructure and mechanical properties investigations of AZ91 magnesium alloy as-cast and after heat treatment are presented. Cylinder samples for uniaxially compression tests were annealed at a temperature of 423 and 623 K for 16 hours (without solution annealing). Alter annealing at 423 K precipitates of γ-Mg17Al12 phase in areas enriched in aluminum solid solution were observed whereas annealing at 623 K caused only homogenizing of solid solution. Investigated materials showed insignificant changes in ultimate compression strength and clearly increase value of yield strength of samples annealed at 623 K.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.