scholarly journals Titanium Dioxide Coated Graphene Nanosheets as a Reinforcement in Aluminum Matrix Composites Based on Pressure Sintering Process

2020 ◽  
Author(s):  
Zheng-Hua Guo ◽  
Qingjie Wu ◽  
Ning Li ◽  
Li-Hong Jiang ◽  
Wen He ◽  
...  

Abstract Graphene nanoplatelets (GNPs) reinforced 7075 aluminum (Al) nanocomposites were successfully synthesized using the powder metallurgy method. A novel method for optimizing interfacial bonding by coating titanium dioxide (TiO 2 ) on the surface of GNPs was proposed in this manuscript. The effects of GNPs on mechanical properties and microstructure of the aluminum matrix nanocomposites, both with and without TiO 2 coating layers, have been investigated. Experimental results showed that the corresponding mechanical properties of the nanocomposites were further improved when the GNPs have TiO 2 coating layers, compared with the addition of pure GNPs. The yield strength, ultimate tensile strength, and microhardness of the nanocomposites reinforced with TiO 2 -coated GNPs increased by 22.9%, 25.9%, and 20.1%, respectively, in comparison to those of the matrix. The further improvement of the mechanical properties could be attributed to the existence of the coating layer, which optimizes the interface bonding between the reinforcement and the matrix, thereby improving the effectiveness of load transfer.

2021 ◽  
Vol 63 (4) ◽  
pp. 350-355
Author(s):  
Mehmet Ayvaz ◽  
Hakan Cetinel

Abstract To be able to successfully produce ceramic-reinforced aluminum matrix composites by using the powder metallurgy method, the wetting of ceramic reinforcements should be increased. In addition, the negative effects of the oxide layer of the aluminum matrix on sinterability should be minimized. In order to break the oxide layer, the deoxidation property of Mg can be used. Furthermore, by creating a liquid phase, both wettability and sinterability can be improved. In this study, the effects of Mg and Cu alloy elements and sintering phase on the wettability, sinterability, and mechanical properties of Al/B4C composites were investigated. For this purpose, various amounts (5, 10, 20, and 30 wt.-%) of B4C reinforced Al5Cu and Al5Mg matrix composites were produced by the powder metallurgy method. After pressing under 400 MPa pressure, composite samples were sintered for 4 hours. The sintering was carried out in two different groups as solid phase sintering at 560 °C and liquid phase sintering at 610 °C. Despite the deoxidation effect of Mg in Al5Mg matrix composites, higher mechanical properties were determined in Al5Cu composites which were sintered in liquid phase because wettability increased. The highest mechanical properties were obtained in the 20 wt.-% B4C reinforced Al5Cu sample sintered in liquid phase.


2011 ◽  
Vol 87 ◽  
pp. 38-42
Author(s):  
Jin Xiang Wang ◽  
Rui Jin Zhao ◽  
Xiao Li Zhang

The metallic glass particles reinforced aluminum matrix composites without obvious defects were obtained successfully by explosive compaction of mixed powders. The quasi-static compressive mechanical properties of the composites with the reinforcement matrix mass fraction 10%, 15% and 20% respectively were researched recur to universal testing machine of Instron 3367 and self-consistent theory. Finally, reinforcement mechanism of the metallic glass particles on the matrix was analyzed by numerical simulation recur to LS-DYNA program. The results show that the mechanical properties obtained by self-consistent theory are well accord with the experimental results; compared with pure aluminum, the yield stress of the composites with metallic glass particles reinforcement of the mass fraction 20% enhances 46.8 percent; the main reinforcement mechanism is the amorphous particles can undertake higher loading, the combined quality of the reinforcement particles with the matrix and the distribute uniformity of the reinforcement particles are important factors which will affect the reinforcement effects.


2017 ◽  
Vol 898 ◽  
pp. 917-932 ◽  
Author(s):  
Yong Wang ◽  
Ji Xue Zhou ◽  
Kai Ming Cheng ◽  
Jian Hua Wu ◽  
Yuan Sheng Yang

Graphene with unique two-dimensional structure and excellent mechanical properties, is one of the most ideal reinforcements. With the increasing progress of aluminum matrix composites, graphene reinforced aluminum matrix composites have attracted great interests. This paper mainly reviews the latest progress on preparation of graphene reinforced aluminum matrix composites, and especially discusses the effective dispersion technique of graphene. Meanwhile, the microstructure and interfacial structure of graphene reinforced aluminum matrix composites are also emphasized and discussed. The results showed that graphene can significantly improve the mechanical properties of composites and refine the matrix grain. By controlling preparation parameters, the graphene agglomeration can be effectively solved, and the adverse interface reaction between graphene and substrate can be avoided. Finally, the current challenges and solutions of graphene reinforced aluminum matrix composites were presented.


2020 ◽  
Vol 988 ◽  
pp. 17-22
Author(s):  
Suryana ◽  
Indah Uswatun Hasanah ◽  
Muhammad Fikri Fadhillah ◽  
Yordan Valentino Putra

The effects of graphite and magnesium (Mg) addition on mechanical properties and microstructure of aluminum matrix composites (AMCs) have been investigated in this work. Aluminum alloy (ADC-12) was combined with graphite and Mg produced by stir casting. The effect of addition of graphite into the matrix has been studied with variation 2, 4 and 6 wt-% for each composite. The addition of Mg as wetting agent was introduced wit 0.4, 0.6 and 0.8 wt-% to promote wettability between ADC-12 and graphite. All composites were characterized both microstructures analysis and mechanical properties include tensile strength and hardness. The higher reinforcement content, the higher porosity formed, due to the tendency of de-wetting as well as particles agglomeration. One of the main intermetallic phase present evenly in aluminum matrix is Mg2Si. The addition of magnesium in the material that will form Mg2Si primary phases which have a high hardness value of these composites.


2020 ◽  
Vol 993 ◽  
pp. 730-738
Author(s):  
Zhong Run Xiao ◽  
Jun Hui Nie ◽  
Jian Zhong Fan

The effect of segregation defect of SiC particles on the properties of materials was studied. 15% SiCp/2009Al composites were prepared by powder metallurgy (PM). Special SiC/Al samples were added to 15% SiCp/2009Al composites. These SiC/Al samples with different sizes and volume fractions were 25%, 35%, 45% and 60%, respectively, which resulted in SiC particulates segregation defect. The 15% SiCp/2009Al composites with defects were tested by ultrasonic testing. Tensile samples were obtained at the locations, where defects might be detected and the mechanical properties were tested. The results showed that all defective samples were cracked at the defective location. The difference in tensile strength between the samples of defect and the samples without defect was large. The toughness of the sample containing the defect reduced and the brittleness increased. The dimples on the matrix indicate that ductile fracture occurred during the fracture process. The cleavage fracture or cracking of the SiC particulates indicated that the stress can be effectively transferred from the matrix to the particles, and the particulates strengthen the matrix well. However, the sample with defect led to brittle fracture in the defect, and a crack source produced at the interface, resulting in a significant decrease in the mechanical properties of the material. If the inhomogeneous distribution of particulate containing a large area was found in the ultrasonic testing of the aluminum matrix composites, the tensile properties of the products generally cannot meet the requirement for application.


2017 ◽  
Vol 5 (2) ◽  
pp. 20-30
Author(s):  
Zaman Khalil Ibrahim

In this research aluminum matrix composites (AMCs) was reinforced by titanium carbide (TiC) particles and was produced. Powder metallurgy technique (PM) has been used to fabricate AMCs reinforced with various amounts (0%, 4%, 8%, 12%, 16% and 20% volume fraction) of TiC particles to study the effect of different volume fractions on mechanical properties of the Al-TiC composites. Measurements of compression strength and hardness showed that mechanical properties of composites increased with an increase in volume fraction of TiC Particles. Al-20 % vol. TiC composites exhibited the best properties with hardness value (97HRB) and compression strength value (275Mpa).


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