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The method of "in-situ tensile testing in SEM" is suitable for investigations of fracture mechanisms because it enables to observe and document deformation processes directly, and so the initiation and development of plastic deformation and fracture can be reliably described. With increasing tensile load, local cracks are formed by rupture of large...
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... surface and propagated approximately perpendicularly to the tensile load direction. Coales- cence of the final fracture progressed along densely populated rows of Al 4 C 3 (A, B) particles parallel to the load direction, Fig. 4. The morphology and size of the deformed surface and three categories of particles on fracture surface can be seen in Fig. 5. A detailed study of the deformation changes showed that the crack initiation was caused by de- cohesion, and occasionally also by rupture of the large particles. Decohesion is a result of different phys- ical properties of different phases of the system. The Al matrix has significantly higher thermal expansion coefficient and lower ...
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... The method of in situ tensile test in SEM is suitable for observation and evaluation of fracture mechanism directly under the load. This method was used for analyzing Al and Cu systems (Al-Al 4 C 3 systems with different volume fraction of secondary phase [4][5][6] and Cu-Al 2 O 3 system [7,8]), Al-Si-Fe alloys [9] and Al-Si system [10]. Fracture mechanism depends on many factors, for instance amount of dispersion particle, their shape and size, characteristics of matrix material, grain boundary characteristics etc. [11][12][13][14][15][16]. ...
The method of 'in-situ tensile test in SEM' is suitable for investigations of fracture mechanisms because it enables to observe and document deformation processes directly, thank to which the initiation and development of plastic deformation and fracture can be reliably described. The deformation and fracture mechanisms of Cu-Al2O3 nanomaterials with 5 vol. % of Al2O3 phase has been analyzed using technique of the 'in-situ tensile testing in SEM'. It has been shown that the deformation process causes break-up of large Al2O3 particles and decohesion of smaller ones. The final fracture path is influenced also by boundaries of nanograins, through which the principal crack propagates towards the sample exterior surface. Based on the experimental observations a model of damage and/or fracture mechanisms has been proposed.
... The aim of work is to analyze fracture mechanism in the Cu-Al 2 O 3 nanocomposite system and to propose a damage model. The method of in situ tensile test in SEM was used for other materials, too [4][5][6][7][8][9][10]. ...
The method of “in situ tensile testing in SEM” is suitable for investigations of fracture mechanisms because it enables to
observe and document deformation processes directly, thank to which the initiation and development of plastic deformation
and fracture can be reliably described. The deformation and fracture mechanisms of Cu–Al2O3 nanomaterials with 5 vol.% of Al2O3 phase has been analyzed using technique of the “in situ tensile testing in SEM.” It has been shown that the deformation process
causes break-up of large Al2O3 particles and decohesion of smaller ones. The final fracture path is influenced also by boundaries of nanograins, through
which the principal crack propagates towards the sample exterior surface. Based on the experimental observations, a model
of damage and/or fracture mechanisms has been proposed.
... In our previous papers [1][2][3][4][5][6][7][8], based on papers [9][10][11], we used in situ tensile testing in SEM to analyse deformation processes in various types of Cu and Al based composites. In [9][10][11] Al-Si-Fe and Al-Si systems were studied by in situ tensile testing in SEM. ...
The deformation and fracture mechanisms of Al-Al4C3 nanomaterials with 4 vol% of Al4C3 phase has been analysed using the technique "in situ tensile testing in SEM". It has been shown that the deformation process causes break-up of large Al4C3 particles and decohesion of smaller ones. The final fracture path is influenced also by boundaries of nanograins, through which the principal crack propagates towards the sample exterior surface. Based on the experimental observations, a model of damage and fracture mechanisms has been proposed.
The main aim of the present work was described quantitative analysis of microstructure of by electron backscatter diffraction (EBSD) technique of dispersion strengthened Al-Al4C3 material. It is a technique by which SEM can be used to evaluate the microstructure by crystallographic analysis based on the acquisition of diffraction patterns from bulk samples. Mechanical properties of dispersion strengthened materials depend on microstructural and substructural parameters, their changes at elevated temperatures and also on grain and subgrain matrix structures. From this point of view the most important microstructural parameters of matrix are size, shape, and misorientation of grains and subgrains and their annealing behaviour. Realized microstructure analyses of Al-Al4C3 material were evaluated from two experimental specimens annealed at different temperatures and times. Obtained microstructures were evaluated and compared. Annealing process has influenced the grain size, shape and orientation of experimental material. Grains size and angle grain boundaries were evaluated from acquired crystal orientation maps.
Creep fracture of a composite based on an aluminum matrix reinforced by 4 vol. % Al4C3 was studied at temperatures of 623 and 723K by small punch testing with a constant force. The composite was tested in state after equal channel angular pressing (ECAP) by two passes of route C as a final operation. It was found that the time to fracture was inversely proportional to the minimum deflection rate in a similar manner as the corresponding quantities in conventional creep tests. The fractured surfaces of the studied materials had largely intercrystalline character.
