RÉSUMÉ
In the current study, a two-stage stir cast process was used to produce Al6082 reinforced with sized graphite particulates, and the material's mechanical and tribological properties were analyzed. The graphite content in the Al6082 alloy was increased from 2 to 6% in steps of 2 wt %. The impact of graphite addition to Al6082 was evaluated using microstructural micrographs, hardness test, tensile test, and wear test outcomes. The matrix alloy's microstructure and particle distribution were analyzed using scanning electron microscopy and energy-dispersive spectroscopy. The microstructure of Al6082 shows that the reinforcement particles are evenly distributed throughout the matrix. Although the hardness of metal-matrix composites was slightly reduced when graphite was added at concentrations of up to 6 wt %, the material's tensile strength and wear resistance were significantly improved. Micrographs taken by a microscope were used to examine the fractured surfaces of tensile test specimens. Wear experiments were performed using a conventional pin-on-disc tribometer to examine the tribological properties of both unreinforced matrix and graphite composites. With the addition of 2, 4, and 6 wt % of graphite particles, the composites' wear resistance was significantly improved. Wear of alloys and their composites was analyzed to determine how load and sliding speed impacted wear loss.
RÉSUMÉ
The present study aims at producing transient liquid phase (TLP) bonded Al2219 joints with pure Cu (copper) as an interlayer. The TLP bonding is carried out at the bonding temperatures in the range of 480 to 520 °C while keeping the bonding pressure (2 MPa) and time (30 min.) constant. Reaction layers are formed at the Al-Cu interface with a significant increase in diffusion depth with the increase in the bonding temperature. The microstructural investigations are carried out using scanning electron microscopy and energy-dispersive spectroscopy. X-ray diffraction study confirms the formation of CuAl2, CuAl, and Cu9Al4 intermetallic compounds across the interface of the bonded specimens. An increase in microhardness is observed across the bonding zone with the increase in the bonding temperature, and a maximum hardness value of 723 Hv is obtained on the diffusion zone of the specimen bonded at 520 °C. Furthermore, the fractography study of the bonded specimens is carried out, and a maximum shear strength of 18.75 MPa is observed on the joints produced at 520 °C.
RÉSUMÉ
An Al2014-alumina (Al2O3) composite's characteristics are significantly influenced by the reinforcement particle size variation. Therefore, this study examines the microstructure, mechanical, fractography, and wear performance of an Al2014-Al2O3p composite made using a unique two-stage stir casting method and various alumina weight fractions (9, 12, and 15 wt %). Three categories of alumina particle size are used, i.e., fine particle size (FPS, 8 µm), intermediate particle size (IPS, 53 µm), and coarse particle size (CPS, 88 µm). The shapes of the composites were characterized using scanning electron microscopy. According to scanning electron microscopic analyses of the microstructure, the FPS dispersion was more uniform than IPS and CPS, whereas CPS causes agglomeration. Additionally, the studies show that the FPS composite outperformed CPS and IPS composites in terms of mechanical characteristics and wear performance. The fractography study shows conical and equiaxed dimple failure in the Al2014 matrix and the circular cavities.
