The Effect of Incorporating Ceramic Particles with Different Morphologies on the Microstructure, Mechanical and Tribological Behavior of Hybrid TaC_ BN/AA2024 Nanocomposites

Improving the mechanical durability and wear resistance of aluminum alloys is a research challenge that can be solved by their reinforcement with ceramics. This article is concerned with the improvement of the mechanical properties and wear resistance of the AA2024 aluminum alloy surface. Surface composites were prepared by incorporating a hybrid of heavy particles (tantalum carbide (TaC), light nanoparticles, and boron nitride (BN)) into the AA2024 alloy using the friction stir process (FSP) approach. Three pattern holes were milled in the base metal to produce the composites with different volume fractions of the reinforcements. The effects of the FSP and the reinforcements on the microstructure, mechanical properties, and wear resistance are investigated. In addition to the FSP, the reinforced particles contributed to greater grain refinement. The rolled elongated grains became equiaxed ultrafine grains reaching 6 ± 1 µm. The refinement and acceptable distribution in the reinforcements significantly improved the hardness and wear resistance of the produced composites. Overall, the hardness was increased by 60% and the wear resistance increased by 40 times compared to the base alloy.

Study on corrosion resistance of superhydrophobic surface on aluminum alloy

Anti-corrosion of aluminum alloys with different roughness were researched in this study. To further verify the relationship between anti-corrosion and surface roughness, surface with micro structure alloy was successfully fabricated via anode oxidation on aluminum. The water contact angle of aluminum alloy surface after coating polypropylene film was 154° and sliding angle was 3°. The micro-nano structure was constructed by adding nano-SiO2. The contacts angle of surface was 165° and the sliding angle was 1.8°. The superhydrophobic samples were used to test corrosion resistance. Compared with aluminum coated with unmodified film, the corrosion potential for modified superhydrophobic aluminum alloy increased by about 0.05 V. When nano-SiO2 particles were added, the corrosion resistance for the sample was also improved.

Recent development in friction stir processing of aluminum alloys: Microstructure evolution, mechanical properties, wear and corrosion behaviors

In this paper, the effect of mechanical vibration with reinforcement particles namely Silicon Carbide (SiC) on microstructure, mechanical properties, wear, and corrosion behaviors of aluminum alloy surface composites fabricated via friction stir processing (FSP) was investigated. The method was entitled friction stir vibration process (FSVP). The results revealed that recrystallized fine grains formed in all processing samples as a result of dynamic recovery and recrystallization, while samples processed in friction stir vibration processing resulted in better grain refinement in the stir zone than in conventional friction stir processing. Compared to conventional friction stir processing, in friction stir vibration processing, the hardness and tensile strength increased due to microstructure modification and better reinforcing distribution. From corrosion analysis, the corrosion resistance of the friction stir vibration processed samples showed a significant increase compared to the friction stir processed specimens. The wear results indicated that the wear resistance of friction stir vibration processed specimens is higher than friction stir processed specimens due to the development of smaller grains and a more homogenous distribution of the strengthening particles as the vibration is applied.

Regularities of the Formation of a Green Superhydrophobic Protective Coating on an Aluminum Alloy after Surface Modification with Stearic Acid Solutions

It has been shown that solutions of stearic acid in a dimethyl sulfoxide–water binary mixture allow superhydrophobic protective coatings to be created on an aluminum alloy surface with a minimum impact on the environment. The superhydrophobicity and self-cleaning ability of the coating that we developed have been confirmed by measurements of droplet wetting angles and roll-off angles. These properties appear due to the formation of a multimodal micro-rough surface that mainly consists of aluminum stearate. The coatings formed in this manner have been studied by ellipsometry, XPS, and scanning probe microscopy. Their protective ability has been estimated by the “droplet-express” method and in a salt fog chamber. The protective ability of the coating is determined by the DMSO/H2O ratio, the concentration of stearic acid, and the duration and temperature of modification of the aluminum alloy; it is controlled by a competition between the processes of aluminum stearate formation and hydrolysis. It has been shown that adsorption of stearic acid on an aluminum stearate coating increases its permeability and decreases its protective capability. The results presented in this article are useful for optimizing the conditions of applying green superhydrophobic stearate coatings on aluminum alloys in order to achieve a maximum protective effect.

Facile Fabrication of Durable Superhydrophobic Aluminum Alloy Surfaces by HS-WEDM and Chemical Modification

Durable superhydrophobic aluminum alloy surfaces were prepared through a facile method: combining high-speed wire electrical discharge machining and chemical modification. Three types of pulse width were selected to machine the aluminum alloy surfaces with different levels of surface roughness. The effect of immersion time in perfluorooctanoic acid on the wettability of the aluminum alloy surfaces was examined. The contact angle of the superhydrophobic aluminum alloy surfaces was [Formula: see text], and the sliding angle was [Formula: see text]. After sanding with coarse sandpaper, the aluminum alloy surfaces still exhibited superhydrophobicity with a stroke of 450[Formula: see text]cm, indicating good mechanical durability. The prepared superhydrophobic aluminum alloy surface heated for 2[Formula: see text]h within the 190–240∘C temperature range showed favorable thermal stability. In addition, the superhydrophobic aluminum alloy surface exhibited self-cleaning property. Therefore, the superhydrophobic aluminum alloy surface prepared by using the simple mass production method showed good mechanical stability, thermal stability, and self-cleaning property, as well as broad application potential.