Enhancement of Physical Properties and Corrosion Resistance of Al-Cu-Al2O3/Graphene Nanocomposites by Powder Metallurgy Technique

Abstract

In this study, we enhanced the adhesion of graphene nanosheets to achieve homogeneous dispersion, consequently improving the electrical and thermal conductivity, coefficient of thermal expansion, and corrosion resistance with an aluminum matrix containing up to 1.5 wt. % graphene. First, 2.5 wt. % Al2O3 and varying ratios of graphene up to 1.5 wt. % were coated with 5 wt. % silver nanoparticles to metalize their surfaces. Predetermined portions of coated alumina and graphene were mixed with Al/10 wt. % Cu powder for 45 h. Mixed samples were compacted under 600 MPa and sintered at 565 °C in a vacuum furnace for 60 min with a low heating rate of 2 °C/min. The strengthening effect of the added materials on the density, microstructure, electrical and thermal conductivities, thermal expansion, and corrosion behavior of aluminum were investigated. Excellent adhesion and homogeneous dispersion of the investigated reinforcements were achieved. Three phenomena were observed: (1) an improvement in the densification, electrical and thermal conductivity, thermal expansion, and corrosion rate by adding 10 wt. % Cu to the aluminum matrix; (2) deterioration of the properties of Al/10 wt. % Cu with the addition of 2.5 wt. % alumina nanoparticles; and (3) improved properties with the addition of graphene nanosheets up to 1 wt. % and a decrease in property values beyond 1.5 wt. % graphene content due to the formation of agglomerations and pores in the metal matrix.

Fabrication and characterization of Ti–12Mo/xAl2O3 bio-inert composite for dental prosthetic applications

“…In addition, the formation of pores and agglomeration of Al 2 O 3 nanoparticles are observed in the Ti–12Mo/10–15 wt% Al 2 O 3 nanocomposite. The pore formation may be due to the limited wettability between the Al 2 O 3 nanoparticles and the matrix ( Chen et al, 2021 ; El-Kady et al, 2022 ). The addition of nano-Al 2 O 3 with 5 wt% affects the particle size of Mo, as shown in image c .…”

“…The presence of Al 2 O 3 nanoparticles on the grain boundaries of the binary Ti–Mo particles may decrease the dislocation movements and consequently increase the hardness ( Chen et al, 2021 ; Hossam and Allam, 2021 ; El-Kady et al, 2022 ). Regardless of the decrease in hardness of the Ti–12Mo/10 and 15 wt% Al 2 O 3 nanocomposites, they are still greater than the hardness of the Ti–Mo composite.…”

Manufacturing of Aluminum Nano-Composites Reinforced with Nano-Copper and High Graphene Ratios Using Hot Pressing Technique

“…The addition of 15 wt% Cu to the pure aluminum sample raised the hardness to 230 HV. This improvement may be related to the formation of Cu9Al4 intermetallic that has exceptionally high hardness [38,39]. In addition, Cu added to Al is expected to increase the alumina content, while Al reduces the oxygenation of Cu.…”

Integrated Intelligent Method Based on Fuzzy Logic for Optimizing Laser Microfabrication Processing of GnPs-Improved Alumina Nanocomposites

“…Alumina/graphene nanocomposites with varying graphene contents have been successfully produced through powder metallurgy technologies such as high-frequency induction heating (HFIHs), hot pressing (HP), spark plasma sintering (SPS), and hot isostatic pressing (HIP). Many studies have focused on enhancements in the properties of the Al 2 O 3-based nanocomposites after adding the graphene reinforcement material [12][13][14][15][16][17][18][19][20][21][22]. Thereafter, micromachining becomes essential after their fabrication to meet the requirements of the desired application, either as micro components or products.…”