Ale Contreras - Academia.edu (original) (raw)

Papers by Ale Contreras

Research paper thumbnail of Fabricación y caracterización de materiales compuestos de matriz metálica Al-Cu y Al-Mg reforzados con partículas de TiC

Revista Mexicana De Fisica, 2004

Research paper thumbnail of Processing and Characterization of Al-Cu and Al-Mg Base Composites Reinforced with TiC

Advanced Engineering Materials, 2004

Uncoated and coated SiC fibers were cut by a CO2 laser. The laser RS500/ 700 was supplied by ROFI... more Uncoated and coated SiC fibers were cut by a CO2 laser. The laser RS500/ 700 was supplied by ROFIN-SINAR Hamburg, Germany. For cutting two plates on which the fibers were fixed with adhesive tapes were prepared. These plates were separated by a distance of 2,5 cm. At ...

Research paper thumbnail of Structural, morphological and interfacial characterization of Al–Mg/TiC composites

Materials Characterization, 2007

Morphological and structural characterization of Al–Mg/TiC composites obtained by infiltration pr... more Morphological and structural characterization of Al–Mg/TiC composites obtained by infiltration process and wetting by the sessile drop technique were studied. Focusing at the interface, wetting of TiC substrates by molten Al–Mg-alloys at 900 °C was investigated. Electron probe microanalysis (EPMA) indicated that aluminum carbide (Al4C3) is formed at the interface and traces of TiAl3 in the wetting assemblies were detected. Scanning Electron Microscopy (SEM) observations show that TiC particles do not appear to be uniformly attacked to produce a continuous layer of Al4C3 at the interface. Molten Al–Mg-alloys were infiltrated into TiC preforms with flowing argon at a temperature of 900 °C. In the composites no reaction phase was observed by SEM. Quantification of the Al phase in the composite was carried out by X-ray diffraction (XRD) and Rietveld analysis. Chemical mapping analyzed by SEM shows that the Al–Mg alloy surrounds TiC particles. In the composites with 20 wt.% of Mg the Al–Mg-β phase was detected through XRD.

Research paper thumbnail of Wetting of TiC by Al–Cu alloys and interfacial characterization

Journal of Colloid and Interface Science, 2007

The wetting behavior and the interfacial reactions that occurred between molten Al–Cu alloys (1, ... more The wetting behavior and the interfacial reactions that occurred between molten Al–Cu alloys (1, 4, 8, 20, 33, and 100 wt% Cu) and solid TiC substrates were studied by the sessile drop technique in the temperature range of 800–1130 °C. The effect of wetting behavior on the interfacial reaction layer was studied. All the Al–Cu alloys react with TiC at the interface forming an extensive reaction layer. The interface thickness varied with the samples, and depends on the temperature, chemical composition of the alloy and the time of the test. Wetting increases with increasing concentration of copper in the Al–Cu alloy at 800 and 900 °C. In contrast, at higher temperature such as 1000 °C wetting decreases with increasing copper content. The spreading kinetics and the work of adhesion were evaluated. The high values of activation energies indicated that spreading is not a simple viscosity controlled phenomenon but is a chemical reaction process. The spreading of the aluminum drop is observed to occur according to the formation of Al4C3, CuAl2O4, CuAl2, TiCux mainly, leading to a decreases in the contact angle. As the contact angle decreases the work of adhesion increases with increasing temperature. Al–Cu/TiC assemblies showed cohesive fracture corresponding to a strong interface. However, using pure Cu the adhesion work is poor, and the percentage of cohesion work is also too low (27–34%).Wetting behavior and interfacial reactions occurred between molten Al–Cu alloys (1, 4, 8, 20, 33, and 100 wt% Cu) and solid TiC substrates were studied by the sessile drop technique.

Research paper thumbnail of Fabricación y caracterización de materiales compuestos de matriz metálica Al-Cu y Al-Mg reforzados con partículas de TiC

Revista Mexicana De Fisica, 2004

Research paper thumbnail of Processing and Characterization of Al-Cu and Al-Mg Base Composites Reinforced with TiC

Advanced Engineering Materials, 2004

Uncoated and coated SiC fibers were cut by a CO2 laser. The laser RS500/ 700 was supplied by ROFI... more Uncoated and coated SiC fibers were cut by a CO2 laser. The laser RS500/ 700 was supplied by ROFIN-SINAR Hamburg, Germany. For cutting two plates on which the fibers were fixed with adhesive tapes were prepared. These plates were separated by a distance of 2,5 cm. At ...

Research paper thumbnail of Structural, morphological and interfacial characterization of Al–Mg/TiC composites

Materials Characterization, 2007

Morphological and structural characterization of Al–Mg/TiC composites obtained by infiltration pr... more Morphological and structural characterization of Al–Mg/TiC composites obtained by infiltration process and wetting by the sessile drop technique were studied. Focusing at the interface, wetting of TiC substrates by molten Al–Mg-alloys at 900 °C was investigated. Electron probe microanalysis (EPMA) indicated that aluminum carbide (Al4C3) is formed at the interface and traces of TiAl3 in the wetting assemblies were detected. Scanning Electron Microscopy (SEM) observations show that TiC particles do not appear to be uniformly attacked to produce a continuous layer of Al4C3 at the interface. Molten Al–Mg-alloys were infiltrated into TiC preforms with flowing argon at a temperature of 900 °C. In the composites no reaction phase was observed by SEM. Quantification of the Al phase in the composite was carried out by X-ray diffraction (XRD) and Rietveld analysis. Chemical mapping analyzed by SEM shows that the Al–Mg alloy surrounds TiC particles. In the composites with 20 wt.% of Mg the Al–Mg-β phase was detected through XRD.

Research paper thumbnail of Wetting of TiC by Al–Cu alloys and interfacial characterization

Journal of Colloid and Interface Science, 2007

The wetting behavior and the interfacial reactions that occurred between molten Al–Cu alloys (1, ... more The wetting behavior and the interfacial reactions that occurred between molten Al–Cu alloys (1, 4, 8, 20, 33, and 100 wt% Cu) and solid TiC substrates were studied by the sessile drop technique in the temperature range of 800–1130 °C. The effect of wetting behavior on the interfacial reaction layer was studied. All the Al–Cu alloys react with TiC at the interface forming an extensive reaction layer. The interface thickness varied with the samples, and depends on the temperature, chemical composition of the alloy and the time of the test. Wetting increases with increasing concentration of copper in the Al–Cu alloy at 800 and 900 °C. In contrast, at higher temperature such as 1000 °C wetting decreases with increasing copper content. The spreading kinetics and the work of adhesion were evaluated. The high values of activation energies indicated that spreading is not a simple viscosity controlled phenomenon but is a chemical reaction process. The spreading of the aluminum drop is observed to occur according to the formation of Al4C3, CuAl2O4, CuAl2, TiCux mainly, leading to a decreases in the contact angle. As the contact angle decreases the work of adhesion increases with increasing temperature. Al–Cu/TiC assemblies showed cohesive fracture corresponding to a strong interface. However, using pure Cu the adhesion work is poor, and the percentage of cohesion work is also too low (27–34%).Wetting behavior and interfacial reactions occurred between molten Al–Cu alloys (1, 4, 8, 20, 33, and 100 wt% Cu) and solid TiC substrates were studied by the sessile drop technique.