Nano-Sized Al2O3-Gr Reinforced Al7075 Hybrid Composite: Impact of Cooling Agents on Mechanical, Wear, and Fracture Behavior.

Aluminum metal cast composites (AMCCs) are frequently used in high-tech sectors such as automobiles, aerospace, biomedical, electronics, and others to fabricate precise and especially responsible parts. The mechanical and wear behavior of the metal matrix composites (MMCs) is anticipated to be influenced by the cooling agent's action and the cooling temperature. This research paper presents the findings of a series of tests to investigate the mechanical, wear, and fracture behavior of hybrid MMCs made of Al7075 reinforced by varying wt % of nano-sized Al2O3 and Gr and quenched with water and ice cubes. The heat-treated Al7075 alloy hybrid composites were evaluated for their hardness, tensile, and wear behavior, showcasing a significant process innovation. The heat treatment process greatly improved the hybrid composites' mechanical and wear performance. The samples quenched in ice attained the highest hardness of 119 VHN. There is a 45.37% improvement in the hardness of base alloy with the addition of 3% of Al2O3 and 1% of graphite particles. Further, the highest tensile and compression strengths were found in the ice-quenched 3% Al2O3 and 1% graphite hybrid composites with improvements of 34.2 and 48.83%, respectively, compared to the water-quenched base alloy. Under the samples quenched in ice, the mechanical and wear behavior improved. The tensile fractured surface showed voids, particle pullouts, and dimples. The worn-out surface of wear test samples of the created hybrid composite had micro pits, delamination layers, and microcracks.

Influence of Graphite Particles on the Mechanical and Wear Characterization of Al6082 Alloy Composites.

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.

Impact of Boron Carbide Particles and Weight Percentage on the Mechanical and Wear Characterization of Al2011 Alloy Metal Composites.

Micron-sized B4C addition to the Al2011 alloy was investigated for its impact on mechanical and wear performance. The stir-casting method was used to manufacture the Al2011 alloy metal matrix composites reinforced with varying percentages of B4C particulates (2, 4, and 6). The microstructural, mechanical, and wear properties of the synthesized composites were tested. scanning electronic microscope (SEM) microscopy and XRD patterns were used to characterize the microstructure of the samples that were obtained. The XRD patterns confirmed the presence of B4C particles. The addition of B4C reinforcement increased the metal composite's hardness, tensile strength, and compressive strength. Incorporating the reinforcement resulted in a decrease in elongation for the Al2011 alloy composite. The wear behavior of the prepared samples was examined under various load and speed conditions. In terms of wear resistance, the microcomposites were far superior. SEM observations of the Al2011-B4C composites revealed numerous fracture and wear mechanisms.

Impact of Bonding Temperature on Microstructure, Mechanical, and Fracture Behaviors of TLP Bonded Joints of Al2219 with a Cu Interlayer.

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.

Al2014-Alumina Aerospace Composites: Particle Size Impacts on Microstructure, Mechanical, Fractography, and Wear Characteristics.

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.

Microstructural Evolution, Tensile Failure, Fatigue Behavior and Wear Properties of Al2O3 Reinforced Al2014 Alloy T6 Heat Treated Metal Composites.

The paper focused on an experimental study on the microstructural, mechanical, and wear characteristics of 15 wt.% alumina (Al2O3) particulates with an average particle size of 20 µm, reinforced in Al2014 alloy matrix composite as-cast and heat-treated samples. The metal matrix composite (MMC)samples were produced via a novel two-stage stir-casting technique. The fabricated composite samples were subjected to evaluate hardness, tensile strength, fatigue behavior and wear properties for both as cast and T6 heat-treated test samples. The Al2014 alloy and Al2014-15 wt.% Al2O3 MMCs were in solution for 1 h at a temperature of 525 °C, quenched instantly in cold water, and then artificially aged for 10 h at a temperature of 175 °C. SEM and X-ray diffraction analyses were used to investigate the microstructure and dispersion of the reinforced Al2O3 particles in the composite and the base alloy Al2014. The obtained results indicated that the hardness, tensile and fatigue strength and wear resistance increased when an amount of Al2O3 particles was added, compared to the as-cast Al2014 alloy and it was observed that after subjecting the same composite samples to heat treatment, there was further enhancement in the mechanical and wear properties in the Al2014 matrix alloy and Al2014-15 wt.% Al2O3 composite samples.