Einfluß der verwendeten Kohlenstoff‐Sorten bei der Herstellung von dispersionsgehärteten Al‐Al4C3‐Werkstoffen auf deren Eigenschaften

Jangg, G.; Šlesár, M.; Besterci, Michal; Zbiral, J.

doi:10.1002/mawe.19890200707

Cited by 7 publications

(4 citation statements)

References 3 publications

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“…1 shows the milling kinetics, the effect of milling time on the dislocation density and subgrain size of the matrix. After milling for 120 min these parameters are constant [6]. From the results, it can be inferred that the homogene ity of carbide distribution and contact surface area influ ence the kinetics of transformation Al+C to Al 4 C 3 .…”

Section: Experimental Materials and Methodsmentioning

confidence: 97%

Kinetics of Mechanical Alloying, Mechanical Properties of Micro and Nanostructural Al-C Systems

Besterci¹,

Sülleiová

Velgosová

2012

High Temperature Materials and Processes

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A method of mechanical alloying process is described. Carbon transformation to Al 4 C 3 is characterized within the different heat treatment schedules and nine commercial carbon powders are tested. The micromecha nism of carbon incorporation into the metallic powder, and its compacting are described. The influence of dis persed carbides on mechanical properties is evaluated together with the influence of deformation on microstruc ture and properties. It was proved that the transformation efficiency of carbon to Al 4 C 3 by heat treatment of alumin ium with the porous furnace black and electrographite is higher than that of the hard cracked graphite. Microstruc ture changes consisted of the fracture processes and welding of the particles with incorporation of C phase and forming of final granules. The dispersed phase Al 4 C 3 parti cle size was measured on thin foil structures, and it was constant and as small as 30 nm. The particle size was influenced neither by the carbon type nor by the heat treatment technology applied. Subgrain size measured in the range of 100 grains in thin foils depended on the carbon type, as well. It ranged from 0.3 to 0.7 mm. Using a DSI (depth sensing indentation technique), the Martens hardness, indentation modulus E and deformation work W for Al matrix and Al 4 C 3 particles have been measured. The temperature dependence of ductility, and reduction of area in the temperature range of 623-723 K and strain rate of 10 −1 s −1 , indicated a considerable increase of these properties. In a case when the volume fraction of Al 4 C 3 changes from lower to higher, the grain rotation mecha nism dominates instead of the grain boundary sliding. The comparison of the tensile test results and changes in fracture for the AlAl 4 C 3 system at two temperatures and two strain rates is summarized. The dependence of the minimum deflection rate on the applied force as well as the dependence of the time to fracture on the applied force for two temperature levels (623 and 723 K) by small punch testing are depicted. The composite was tested in two dif ferent states: a) as received by mechanical alloying with hot extrusion (HE) as the final operation and b) ECAPed (mean grain size of 100-200 nm). The dependence of the minimum deflection rate on the applied force as well as the dependence of the time to fracture on the applied force for two temperature levels are evaluated. The anisotropy of the creep properties and fracture using small punch tests for the AlAl 4 C 3 system produced by ECAP were analysed.

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Section: Experimental Materials and Methodsmentioning

confidence: 97%

Kinetics of Mechanical Alloying, Mechanical Properties of Micro and Nanostructural Al-C Systems

Besterci¹,

Sülleiová

Velgosová

2012

High Temperature Materials and Processes

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“…% A1 4 C 3 consists of approximately equiaxial grains that are similar in both sections (Fig. This fact can be caused by the low amount of A1 4 C 3 phase (non-detected by X-ray analysis) and homogeneously distribution of very fine A1 4 Thus this material is not characterized by the preferential grain orientation.…”

Section: Tem Analysismentioning

confidence: 93%

Structural Analysis of Dispersion Strengthened Materials and Processes

Orolínová¹,

Durisin²,

Ďurišinová³

et al. 2009

High Temperature Materials and Processes

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Dispersion strengthened materials are characterized by high strength properties and good temperature stability of structure until to temperatures of 0.9 melting temperature of aluminium. Dispersion strengthened Al -A1 4 C 3 materials are prepared by powder metallurgy way and the raw powder mixtures are generally consolidated by hot extrusion obtaining a fully dense material. This work is focused on a study of the microstructure in AI -A1 4 C 3 materials containing 4 and 12 vol. % A1 4 C 3 . The microstructure was analyzed by transmission electron microscopy and X-ray diffraction methods. The several microstructural features: morphology, size and distribution of particles of dispersoid, grain size and crystallite size of aluminium matrix, micro strain and dislocations density in materials were determined. The aim is an analysis of the effect of A1 4 C 3 amount on the microstructure formation during hot extrusion and analysis of the microstructure evolution at temperature loading and after cooling to ambient temperature.After hot extrusion the Al -12 vol. % A1 4 C 3 alloy is characterized by finer grains, higher micro strain and dislocations density and by a very low intensity of aluminium matrix deformation texture in comparison to Al -4 vol. % A1 4 C 3 material. In the hot extruded system with 4 vol. % A1 4 C 3 a strong deformation texture was observed. Therefore the amount of dispersoid strongly affects the formation of microstructures. The higher volume of A1 4 C 3 particles provides effective hindrance of the dislocations motion in Al matrix by the attractive interaction between dislocations and particles during extrusion. Both amounta of A1 4 C 3 dispersoid insure the thermal stability of microstructure of analyzed materials to 773 K.

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“…For dislocation density measurement indirect method of XRD was used and the results were verified by direct Hamm´s method. After milling for 120 min these parameters were constant [8]. From the results, it can be inferred that the homogeneity of carbide distribution and contact surface area influence the kinetics of transformation Al+C to Al 4 C 3 [9].…”

Section: Milling and Carbonisation Kineticsmentioning

confidence: 99%

Mechanical Properties of Al-Al4C3 Composite Produced by Mechanical Alloying

Besterci¹,

Dobeš²,

Sülleiová³

et al. 2013

ujms

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The aim of this paper was to study the influence of different input materials and methods of treatment on the microstructure, mechanical properties and fracture of dispersion strengthened aluminium alloys in the Al-Al 4 C 3 system. It was proved that the transformation efficiency of carbon to Al 4 C 3 by heat treatment of aluminium with the porous furnace black and electrographite is higher than that of the hard cracked graphite. The size of Al 4 C 3 dispersed phase was measured by TEM on thin foil and it was constant and as small as 30 nm. Subgrain size measured in the range of 100 grains in thin foils depended on the carbon type, as well. It ranged from 0.3 to 0.7 µm. The temperature dependence of ductility, and reduction of area in the temperature range of 623 -723 K and strain rate of 10 -1 s -1 , indicated a considerable increase of properties. In a case when the volume fraction of Al 4 C 3 changes from lower to higher, the grain rotation mechanism dominates instead of the grain boundary sliding. The dependence of the minimum deflection rate on the applied force as well as the dependence of the time to fracture on the applied force for two temperature levels (623 and 723 K) by small punch testing is depicted. The anisotropy of the creep properties and fracture using small punch tests for the Al-Al 4 C 3 system produced by ECAP were analysed.

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Einfluß der verwendeten Kohlenstoff‐Sorten bei der Herstellung von dispersionsgehärteten Al‐Al₄C₃‐Werkstoffen auf deren Eigenschaften

Abstract: Es hat sich gezeigt, daB die RiBinitiierung stets an Einschlussen beginnt, mit einigen Ausnahmen bei dem Stahl der Werkstoff-Nr.

Cited by 7 publications

References 3 publications

Kinetics of Mechanical Alloying, Mechanical Properties of Micro and Nanostructural Al-C Systems

Kinetics of Mechanical Alloying, Mechanical Properties of Micro and Nanostructural Al-C Systems

Structural Analysis of Dispersion Strengthened Materials and Processes

Mechanical Properties of Al-Al<sub>4</sub>C<sub>3</sub> Composite Produced by Mechanical Alloying

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