Fabrication of Aluminum/Gr Composites and Investigation of its Tribological and Wear Properties

Nowadays metal matrix composites are popular in many industries due to their desirable properties. Severe plastic deformation techniques usually are popular to fabricate metal matrix composites. In this study and as its novelty, Al/Gr composites have been manufactured via a new novel technique, powder metallurgy and press bonding process. Then, as a function of Gr as additive part in this study, tribological, mechanical and microstructure properties of Al/Graphite composites were studied. The tribo surface and microstructure of composites have been investigated more over using SEM microscopy. The density and wear rate of samples increased and the hardness and friction coefficient decrease and by increasing the Gr content. Results showed that addition of Gr into Al matrix can improve the tribological properties of composite

Roll Bonding Properties of Al/Cu Bimetallic Laminates Fabricated by the Roll Bonding Technique

Roll bonding (RB) of bimetal laminates is a solid phase method of bonding and has been widely used in the manufacturing of layered strips. This process is widely used for brazing sheet for automotive, aerospace, vessel, and electrical industries. In this study, 1-mm bimetallic aluminum 1050 and pure copper (Al/Cu) laminates were produced using the roll bonding (RB) process. The RB process was carried out with thickness reduction ratios of 10%, 20%, and 30%, separately. Particular attention was focused on the bonding of the interface between Al and Cu layers. The optimization of thickness reduction ratios was obtained for the improvement of the bond strength of bimetallic laminates during the RB process. Also, the RB method was simulated using finite element simulation in ABAQUS software. Finite Element (FE) simulation was used to model the deformation of bimetallic laminates for various thickness reduction ratios, rolling temperatures, and tensile stresses. Particular attention was focused on the rolling pressure of Al and Cu layers in the simulation. The results show that the stress distribution in the bimetal Al/Cu laminates is an asymmetrical distribution. Moreover, the bonding strength of samples was obtained using the peeling test. Also, the fracture surface of roll bonded samples around the interface of laminates after the tensile test was studied to investigate the bonding quality by scanning electron microscopy (SEM)

Mechanical and Wear Properties of Al/TiC Composites Fabricated via Combined Compo-Casting and APB Process

One of the popular techniques to fabricate metal matrix composites is the compo-casting process. The un-uniform spreading of reinforced subdivisions (particles) inside the metallic matrix and the lack of desirable mechanical properties of the final produced composites due to the low bonding strength among the metal matrix and reinforcement particles are the main challenges in this process. The warm accumulative press bonding (APB) technique was utilized as the supplementary technique to improve the mechanical and microstructural evolution of casted Al/TiC composite bars to remove these difficulties. So, using the tensile test, average Vickers micro hardness test, wear test and scanning electron microscopy (SEM), the microstructure evolution and mechanical properties of these composites have been considered vs. various WAPB steps. The SEM morphology of samples revealed that big titanium carbide clusters are broken and make a uniform distribution of titanium carbide particles at higher APB steps. It was shown that the cumulative forming steps of the APB process improved the mechanical properties of composites. In general, combining the compo-casting and APB process would result in making Al/TiC composites with high uniformity and good mechanical and microstructural properties

Mechanical and Wear Properties of Al/TiC Composites Fabricated via Combined Compo-Casting and APB Process

One of the popular techniques to fabricate metal matrix composites is the compo-casting process. The un-uniform spreading of reinforced subdivisions (particles) inside the metallic matrix and the lack of desirable mechanical properties of the final produced composites due to the low bonding strength among the metal matrix and reinforcement particles are the main challenges in this process. The warm accumulative press bonding (APB) technique was utilized as the supplementary technique to improve the mechanical and microstructural evolution of casted Al/TiC composite bars to remove these difficulties. So, using the tensile test, average Vickers micro hardness test, wear test and scanning electron microscopy (SEM), the microstructure evolution and mechanical properties of these composites have been considered vs. various WAPB steps. The SEM morphology of samples revealed that big titanium carbide clusters are broken and make a uniform distribution of titanium carbide particles at higher APB steps. It was shown that the cumulative forming steps of the APB process improved the mechanical properties of composites. In general, combining the compo-casting and APB process would result in making Al/TiC composites with high uniformity and good mechanical and microstructural properties

Tribological characterization of laminated hybrid AA1050/TiC/Graphite composite bars

Hybrid composites (HC) refer to a type of material that combines aluminum (Al), titanium carbide (TiC), and graphite (Gr) at the nano level. These HC have shown promise in applications requiring high strength, wear resistance (WR), and tribological performance, such as automotive, aerospace, and industrial sectors. In this study, these HC are made using a combination of Powder metallurgy (PM) and accumulative press bonding (APB) processes have been developed. This is the first time that the wear resistance of a hybrid metal matrix composite fabricated with Gr as a solid lubricant has been done and thid is the novelty of this study. In fact, the presence of TiC nanoparticles (NP) provides improved mechanical properties, such as hardness (Hr), strength, and WR for HC. On the other hand, Gr acts as a solid nano-lubricant (NLU) in HC, reducing friction and WR during sliding contact. The presence of Gr-NP also helps to form a durable Gr-nanolayer on tribo surfaces and further improves the WR of HC. This study used a scanning electron microscope (SEM). The results demonstrated that incorporating TiC- NP reduced the WR rate and promoted NL development at extended sliding distances, creating a durable TiC/Gr HC on the TS. Finally, the improved WR of Al/TiC/Gr-HC can be attributed to the stability of the Gr-NL on the TS

Effect of Processing Parameters on Wear Properties of Hybrid AA1050/Al₂O₃/TiO₂ Composites

In this study, hybrid AA1050/Al2O3/TiO2 composites have been produced via combined liquid casting and powder metallurgy techniques. Degassing was utilized to improve the wettability of molten aluminum alloys, and then successful bonding was generated between aluminum matrix and reinforcement particles during the powder metallurgy technique. As the base matrix and reinforcements, AA1050 alloy, Al2O3 and TiO2 particles were taken, respectively. Then, content values of 5Wt.% of Al2O3 in the mesh size of 20 μm and 2.5 and 5 wt. % of TiO2 particles with mesh size of 5μm were added to the AA1050 matrix. For each composite sample, ceramic particles were warmed to 600°C in order to improve wettability and distribution. An identical scattering of subdivisions was observed through aluminum (as matrix) in the microstructural study. To measure the wear resistance, the mechanism of rotary wear test was used. The achieved results illustrated that the fabrication of hybrid composites is an ideal approach to improve the wear resistance of Al-based composites. By increasing of TiO2 Wt.% up to 5% for all composite samples, the wear rate improved to less than half of the monolithic Al alloy value for each composite sample

Bonding evolution of composites fabricated via electrically assisted press bonding

Reducing fuel consumption and increasing efficiency is one of the solutions that humanity has adopted to reduce costs caused by fuel consumption in all industries, including the transportation industry. An effective solution to improve practical fuel consumption is to reduce weight. In principle, press bonding (PB), which is done using a press and is a solid-state welding process, can create a bond between parts with different materials and produce materials with lighter weight and more strength. But it should also be noted that the plasticity of some materials is very low, and these materials are incapable of machinability. Electrical assistance is a potential solution that can solve this problem by increasing the flow tension and reducing the forming force. In this study, aluminum alloy 1060 bars were electrically press bonded at electricity current levels 0 Å up to 300 Å. The effect of pressing parameters on the bonding strength, such as amount of electricity current level and plastic strain, was investigated using a peeling test. Results show that more adhesive among the layers (bonding strength) was attained by growing current and reducing thickness. Scanning electron microscope (SEM) was investigated the peeling surface of samples versus the different thickness reduction ratios and electric currents. The Joule heating effect in the electrically-assisted in press bonding (EAPB) process decreases the forming strength of bars and increases the bond strength of bonded bars by about three times. Using SEM, the peeling surface of samples and the fracture surface around the interface after the tensile test were studied to investigate the bonding quality