The present investigation mainly concentrates on work done in order to explore physical, mechanical & tribological characteristics of Al6061 alloy reinforced with nano-sized zirconium dioxide particulates. Four casts of different percentages of reinforcement from 0 to 6 wt% in the steps of 2 are fabricated using liquid metallurgy technique (stir casting). The prepared composites later subjected to various physical, mechanical & wear tests and results were studied. The tests were carried out in accordance with the ASTM standards on the alloy and nano-composites. In the present investigation the physical and mechanical properties like density, hardness and tensile strength increased significantly with the increase in percentage of reinforcement in the matrix alloy, while the percentage elongation found to be decreased. The sliding wear tests were performed by using pin-on-disc the tribometer and results indicated that wear resistance of composites was higher. Off the four compositions, there were improved properties of composites with higher weight percent of reinforcement. Scanning Electron Microscope (SEM) micrographs was used after tensile testing to study fractured surfaces of specimens and wear morphology after wear testing. Overall the investigational outcomes are very interesting and motivates to do further more research.

Stir-casting with ultrasonic cavitation produced nano-Al₂O₃-filled AA7150 matrix composites in this study. The SEM microstructure study shows that all composites include nano-Al₂O₃ particles with consistent particle sizes and homogenous distribution. EDS and XRD showed no secondary phases or impurities in the composite. Optical microscopy showed intense ultrasonic cavitation effects, and nano-Al₂O₃ particles caused grain refinement in the AA7150 matrix. The composite’s mechanical characteristics improved when the Al₂O₃ nanoparticle weight percentage (wt.%) increased. With only 2.0 wt.% nano-Al₂O₃ particles, the composites yielded 232 MPa, 97.52% higher than the sonicated AA7150 matrix alloy. Multiple models were used to characterize the strength of the AA7150 nano-Al₂O₃ composite. The findings showed that thermal incongruity, Orowan strengthening, the Hall–Petch mechanism, and load transfer effects contributed the most towards the increased strength of the composite. Increasing the nano-Al₂O₃ wt.% in the AA7150 matrix improved hardness by 95.08%, yield strength by 90.34%, and sliding wear resistance by 46.52%. This enhancement may be attributed to the combined effects of better grain refinement, enhanced dispersion with dislocation strengthening, and better load transfer between the matrix and reinforcement, which are assisted by the inclusion of reinforcements. This result was confirmed by optical studies.

The current trend in the materials engineering sector is to develop newer materials that can replace the existing materials in various engineering sectors in order to be more and more efficient. Therefore, the present research work is aimed at fabricating and determining the physical, mechanical, and dry sliding wear properties of titanium carbide (TiC)-reinforced aluminum alloy (Al6061) metal matrix composites (MMCs). For the study, the Al6061-TiC microparticle-reinforced composites were fabricated via the liquid metallurgy route through the stir casting method, where the reinforcement of the TiC particles into the Al6061 alloy matrix was added in the range of 0 to 8.0 wt.%, i.e., in the steps of 2.0 wt.%. The synthesis procedure followed the investigation of the various mechanical properties of Al6061-TiC MMCs, such as the density and structure, as well as mechanical and dry wear experimentation. The tests performed on the casted Al6061, as well as its TiC composites, were in harmony with ASTM standards. As per the experimental outcome, it can be confirmed that the increase in the weight percentage of TiC into the Al6061 alloy substantially increases the density, hardness, and tensile strength, at the expense of the percentage of elongation. In addition, the dry wear experiments, performed on a pin-on-disc tribometer, showed that the Al6061-TiC MMCs have superior wear-resistance properties, as compared to those of pure Al6061 alloy. Furthermore, optical micrograph (OM), powdered X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM) analyses were employed for the developed Al6061-TiC MMCs before and after the fracture and wear test studies. From the overall analysis of the results, it can be observed that the Al6061-TiC composite material with higher TiC reinforcement displays superior mechanical characteristics.

A study on mechanical and fracture properties, through the experimentation techniques has been carried out on a Al 7075-T6 and it coated with an Electroless Nickel deposits of 10–20μm in coating thickness. In the recent years there has been considerable interest in the Electroless Nickel plating due to its extensive use in electronics, automobiles, aerospace and other industries. Electroless Nickel plating is a controlled autocatalytic reduction of nickel ions using suitable reducing agent such as sodium hypophosphite. ASTM Standard – E 399 for plane strain fracture toughness determination was adhered in this investigation. The results obtained, show that the EN coating can give rise to a significant improvement in the fracture behavior (performance) of the substrate and also it has shown that EN coating exhibit a very good adhesive property to the alloy material when the tensile stresses exceeding the yield strength are applied to the system and performance of these pretreatments was studied by SEM analysis