The effect of graphene nano-sheet (GNS) weight percentage on mechanical and corrosion properties of AZ61 and AZ91 based magnesium matrix composites

2020 ◽  
Vol 54 (28) ◽  
pp. 4473-4485 ◽  
Author(s):  
Omer Guler ◽  
Yakup Say ◽  
Burak Dikici

In this study, the effect of graphene nano-sheets (GNSs) on mechanical and corrosion properties of AZ61 and AZ91 based composites was investigated, detail. GNSs have been successfully produced by the liquid phase exfoliation (LPE) method and then, added AZ61 and AZ91 matrix with 01, 0.2, and 0.5 wt% GNSs for the production of the composites. The composite compacts were produced by powder metallurgy technique and sintered for 2 h at 500 °C under Ar atmosphere. The composite characterizations were carried out by scanning and transmission electron microscopes (SEM, TEM), electron dispersive spectroscope (EDS), Raman spectroscopy, and X-ray diffraction. The mechanical properties and corrosion behaviors of the composites have been compared with compression tests and potentiodynamic scanning (PDS) techniques, respectively. The results showed that the compressive strength of the composites increased with increasing GNS amount in both the AZ61 and AZ91 matrix alloys. The most susceptible composites to corrosion for both AZ61 and AZ91 matrix were observed in the 0.5 wt% GNS containing structures. However, there is a certain ratio of GNS in the Mg matrix to achieve good corrosion resistance.

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1777 ◽  
Author(s):  
Ran Yang ◽  
Jiuba Wen ◽  
Yanjun Zhou ◽  
Kexing Song ◽  
Zhengcheng Song

The effects of aluminum on the mechanical properties and corrosion behavior in artificial seawater of Cu-Ni-Fe-Mn alloys were investigated. Cu-7Ni-xAl-1Fe-1Mn samples, consisting of 0, 1, 3, 5, and 7 wt % aluminum along with the same contents of other alloying elements (Ni, Fe, and Mn), were prepared. The microstructure of Cu-7Ni-xAl-1Fe-1Mn alloy was analyzed by Transmission Electron Microscopy (TEM), and its corrosion property was tested by an electrochemical system. The results show that the mechanical and corrosion properties of Cu-7Ni-xAl-1Fe-1Mn alloy have an obvious change with the aluminum content. The tensile strength has a peak value of 395 MPa by adding 3 wt % aluminum in the alloy. Moreover, the corrosion rate in artificial seawater of Cu-7Ni-3Al-1Fe-1Mn alloy is 0.0215 mm/a which exhibits a better corrosion resistance than the commercially used UNS C70600. It is confirmed that the second-phase transformation of Cu-7Ni-xAl-1Fe-1Mn alloy follows the sequence of α solid solution → Ni3Al → Ni3Al + NiAl → Ni3Al + NiAl3. The electrochemical impedance spectroscopy (EIS) shows that the adding element aluminum in the Cupronickel can improve the corrosion resistance of Cu-7Ni-xAl-1Fe-1Mn alloy.


2021 ◽  
Vol 865 ◽  
pp. 158875
Author(s):  
Neera Singh ◽  
Raghunandan Ummethala ◽  
Phani Shashanka Karamched ◽  
Rathinavelu Sokkalingam ◽  
Vasanth Gopal ◽  
...  

2021 ◽  
Vol 887 ◽  
pp. 229-234
Author(s):  
Viktor V. Ovchinnikov ◽  
Svetlana V. Yakutina ◽  
Nadezhda V. Uchevatkina

The effect of high-dose aluminum implantation on the structural-phase state of the surface layer of titanium alloy VT6 with a fine structure (average grain size 2.3 μm) on the mechanical and corrosion properties has been investigated. It is shown that, as a result of ion irradiation, polyphase implanted layers based on α-titanium grains are formed, containing an intermetallic Ti3Al phase along the grain boundaries of α-titanium. The modified surface layers are characterized by improved mechanical properties and corrosion resistance. The noted effect is enhanced by the use of preliminary helium implantation with a dose of 1.3 × 1017 ion / cm2.


2006 ◽  
Vol 519-521 ◽  
pp. 345-350 ◽  
Author(s):  
M. Tanaka ◽  
C. Hénon ◽  
Timothy Warner

RRA treatment was applied to a high-Zn, 7XXX alloy under development for aerospace applications. Microstructure of the alloy is studied at different stages of the 3-step ageing process, by Transmission Electron Microscopy, in order to understand the corresponding evolution of mechanical and corrosion properties. The Compression Yield Strength at the end of the high temperature step was found higher than at the end of the 1st step, contrary to the conventional RRA treatment. After re-ageing, the final CYS turned out significantly higher than at the T6 temper of the alloy, while the material remained sensitive to exfoliation corrosion.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5182
Author(s):  
Katarzyna N. Braszczyńska-Malik

In this paper, a summary of investigations of the microstructure of cast magnesium matrix composites is presented. Analyses of the interfaces between the reinforcing particles and the magnesium alloy matrices were performed. Technically pure magnesium and four various alloys with aluminum and rare earth elements (RE) were chosen as the matrix. The composites were reinforced with SiC and Ti particles, as well as hollow aluminosilicate cenospheres. Microstructure analyses were carried out by light, scanning, and transmission electron microscopy. The composites with the matrix of magnesium and magnesium–aluminum alloys with SiC and Ti particles exhibited coherent interfaces between the components. In the composites based on ternary magnesium alloy with Al and RE with Ti particles, a high-melting Al2RE phase nucleated on the titanium. Different types of interfaces between the components were observed in the composites based on the magnesium–rare earth elements alloy with SiC particles, in which a chemical reaction between the components caused formation of the Re3Si2 phase. Intensive chemical reactions between the components were also observed in the composites with aluminosilicate cenospheres. Additionally, the influence of coatings created on the aluminosilicate cenospheres on the bond with the magnesium matrix was presented. A scheme of the types of interfaces between the components is proposed.


Author(s):  
V. Sathiyarasu ◽  
D. Jeyasimman ◽  
L. Chandra Sekaran

This present research work aims at fabrication of AA7068 metal matrix composite reinforced with a different weight percentage of Al2O3, TiO2 and Cu (0 wt.%, 2 wt.%, and 4 wt.%) nanopowders through mechanical alloying of 30 hrs which is produced using powder metallurgy route. The consolidation pressure of 500 MPa was applied for compaction of the composite and sintered at a temperature of 600°C for two hrs in the presence of argon gas flow. An XRD result reveals that there are no intermetallic compounds formed in the milled powder after 30 hr of mechanical alloying. The reinforcement particles were well embedded and uniformly distributed in matrix composites was confirmed by bright-field emission transmission electron microscopy (FETEM) image and selected area diffraction (SAD) ring pattern. From the DSC curve of AA 7068–2.0 wt. % Al2O3, TiO2 and Cu nanocomposite powders after 30 hrs of mechanical alloying., the endothermic peak at 536.85°C corresponds to the melting of aluminium which was followed by a steady-state exothermic reaction at 579.51°C was obtained. The green density and sintered density of prepared nanocomposites were calculated and compared. Brinell hardness test has been conducted and the maximum value of 192 BHN was obtained by adding a weight percentage of 2 wt. % of Al2O3, TiO2 and Cu particles.


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