Mechanical and physical properties of selected magnesium base nanocomposites (original) (raw)
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A Review on Mechanical Properties of Magnesium Based Nano Composites
AIP Conference Proceedings, 2018
A review was done on Magnesium (Mg) based composite materials reinforced with different nano particles such as TiO2, Cu, Y2O3, SiC, ZrO2 and Al2O3. TiO2 and Al2O3 nanoparticles were synthesised by melt deposition process. Cu, Y2O3, SiC and ZrO2 nanoparticles were synthesised by powder metallurgy process. Composite microstructural characteristics shows that the nano-size reinforcements are uniformly distributed in the composite matrix and also minimum porosity with solid interfacial integrity. The mechanical properties showed yield strength improvement by 0.2 percentage and Ultimate tensile strength (UTS) was also improved for all the nano-particles. But UTS was adversely affected with TiO2 reinforcement while ductility was increased. With Cu reinforcement elastic modulus, hardness and fracture resistance increased and improved the coefficient of thermal expansion (CTE) of Mg based matrix. By Y2O3 reinforcement hardness, fracture resistance was improved and ductility reached maximum by 0.22 volume percentage of Y2O3 and decreased with succeeding increase in Y2O3 reinforcement. The readings exposed that mechanical properties were gathered from the composite comprising 2.0 weight percentage of Y2O3. Ductility and fracture resistance increased with ZrO2 reinforcement in Mg matrix. Using Al2O3 as reinforcement in Mg composite matrix hardness, elastic modulus and ductility was increased but porosity reduced with well interfacial integrity. Dissipation of energy in the form of damping capacity was resolved by classical vibration theory. The result showed that an increasing up to 0.4 volume percentage alumina content increases the damping capacity up to 34 percent. In another sample, addition of 2 weight percentage nano-Al2O3 particles showed big possibility in reducing CTE from 27.9-25.9×10 6 K 1 in Magnesium, tensile and yield strength amplified by 40MPa. In another test, Mg/1.1Al2O3 nanocomposite was manufactured by solidification process followed by hot extrusion. Results showed that strengthening effect was maintained up to 150 C and fracture characteristics of Mg composite transformed from brittle to mixed ductile mode and fully ductile in attendance of nano-Al2O3 particulates.
Tribological characterisation of magnesium matrix nanocomposites: A review
Advances in Mechanical Engineering
Magnesium matrix nanocomposites (Mg-MNCs) are high grade materials widely used in aerospace, electronics, biomedical and automotive sectors for high strength to weight ratio, excellent sustainability and superior mechanical and tribological characteristics. Basic properties of Mg-MNCs rely on type and amount of reinforcement and fabrication process. Current study reviews existing literatures to explore contribution of different parameters on tribological properties of Mg-MNCs. Effects of particle size and amount of different reinforcements like SiC, WC, Al2O3, TiB2, CNT, graphene nano platelets (GNP), graphite on tribological behaviour are discussed. Incorporation of nanoparticles generally enhances properties. Role of different fabrication processes like stir casting (SC), ultrasonic treatment casting (UST), disintegrated melt deposition (DMD), friction stir processing (FSP) on wear and friction behaviour of Mg-MNCs is also reviewed. Contributions of different tribological process ...
Effect of hybrid reinforcement on the high temperature tensile behavior of magnesium nanocomposite
International Journal of Materials Research, 2015
In the present study, results revealed that hybrid (0.7 % yttria + 0.3 % copper) nano-particle reinforcement has a significant strengthening effect on commercially pure magnesium reaching 100 8C, which gradually diminishes with further increase in temperature. Due to the presence of reinforcement particles, magnesium matrix also completely recrystallizes at 100 8C. Hybrid nano-reinforcement also assisted in the deformation process and achieved large ductility at a relatively low temperature.
Journal of Materials Engineering and Performance, 2013
In this paper, the intrinsic influence of nano-alumina particulate (Al 2 O 3p) reinforcements on microstructure, microhardness, tensile properties, tensile fracture, cyclic stress-controlled fatigue, and final fracture behavior of a magnesium alloy is presented and discussed. The unreinforced magnesium alloy (AZ31) and the reinforced composite counterpart (AZ31/1.5 vol.% Al 2 O 3) were manufactured by solidification processing followed by hot extrusion. The elastic modulus, yield strength, and tensile strength of the nanoparticle-reinforced magnesium alloy were noticeably higher than the unreinforced counterpart. The ductility, quantified by elongation-to-failure, of the composite was observably lower than the unreinforced monolithic counterpart (AZ31). The nanoparticle-reinforced composite revealed improved cyclic fatigue resistance over the entire range of maximum stress at both the tested load ratios. Under conditions of fully reversed loading (R = 21) both materials showed observable degradation in behavior quantified in terms of cyclic fatigue life. The conjoint influence of reinforcement, processing, intrinsic microstructural features and loading condition on final fracture behavior is presented and discussed.
Metals, 2012
In this study, metallic elements that have limited/negligible solubility in pure magnesium (Mg) were incorporated in Mg using the disintegrated melt deposition technique. The metallic elements added include: (i) micron sized titanium (Ti) particulates with negligible solubility; (ii) nano sized copper (Cu) particulates with limited solubility; and (iii) the combination of micro-Ti and nano-Cu. The combined metallic addition (Ti + Cu) was carried out with and without preprocessing by ball-milling. The microstructure and mechanical properties of the developed Mg-materials were investigated. Microstructure observation revealed grain refinement due to the individual and combined presence of hard metallic particulates. The mechanical properties evaluation revealed a significant improvement in microhardness, tensile and compressive strengths. Individual additions of Ti and Cu resulted in Mg-Ti composite and Mg-Cu alloy respectively, and their mechanical properties were influenced by the inherent properties of the particulates and the resulting second phases, if any. In the case of combined addition, the significant improvement in properties were observed in Mg-(Ti + Cu) BM composite containing ball milled (Ti + Cu) particulates, when compared to direct addition of Ti and Cu particulates. The change in particle morphology, formation of Ti 3 Cu intermetallic and good interfacial bonding with the matrix achieved due to preprocessing, contributed to its superior strength
Development of new magnesium based alloys and their nanocomposites
Journal of Alloys and Compounds, 2011
In the present study, 1 and 2 wt.% of aluminum were successfully incorporated into magnesium based AZ31 alloy to develop new AZ41 and AZ51 alloys using the technique of disintegrated melt deposition. AZ41-Al 2 O 3 and AZ51-Al 2 O 3 nanocomposites were also successfully synthesized through the simultaneous addition of aluminum (1 and 2 wt.%, respectively) and 1.5 vol.% nano-sized alumina into AZ31 magnesium following same route. Alloy and composite samples were then subsequently hot extruded at 400 • C and characterized. Microstructural characterization studies revealed equiaxed grain structure, reasonably uniform distribution of particulate and intermetallics in the matrix and minimal porosity. Physical properties characterization revealed that addition of both aluminum and nano-sized alumina reduced the coefficient of thermal expansion of monolithic AZ31. The presence of both Al and nano-sized Al 2 O 3 particles also assisted in improving overall mechanical properties including microhardness, engineering and specific tensile strengths, ductility and work of fracture. The results suggest that these alloys and nanocomposites have significant potential in diverse engineering applications when compared to magnesium AZ31 alloy.
Internal friction in microcrystalline magnesium reinforced by alumina particles
Journal of Alloys and Compounds, 2000
Using internal friction measurement, changes in the microstructure of microcrystalline magnesium and magnesium with 3 vol.% of Al O microparticles and nanoparticles, due to thermal treatment, have been investigated. Materials have been thermally treated at 2 3 increasing temperature and then the amplitude dependence of the logarithmic decrement was measured at room temperature. The thermal treatment influences the amplitude-dependent component of the decrement in composite with nanoparticles while in composite with microparticles no influence has been estimated. Thermal stresses induced in the composites due to a difference between thermal expansion coefficient of matrix and ceramic particles may create new dislocations during the cooling from elevated temperatures. Density of new dislocations depends on the particle size. The thermal stresses can achieve yield stress in the matrix and micro-glide of newly created dislocations as well as their annihilation may occur.
Tensile and Compressive Responses of Ceramic and Metallic Nanoparticle Reinforced Mg Composites
Materials, 2013
In the present study, room temperature mechanical properties of pure magnesium, Mg/ZrO 2 and Mg/(ZrO 2 + Cu) composites with various compositions are investigated. Results revealed that the use of hybrid (ZrO 2 + Cu) reinforcements in Mg led to enhanced mechanical properties when compared to that of single reinforcement (ZrO 2 ). Marginal reduction in mechanical properties of Mg/ZrO 2 composites were observed mainly due to clustering of ZrO 2 particles in Mg matrix and lack of matrix grain refinement. Addition of hybrid reinforcements led to grain size reduction and uniform distribution of hybrid reinforcements, globally and locally, in the hybrid composites. Macro-and micro-hardness, tensile strengths and compressive strengths were all significantly increased in the hybrid composites. With respect to unreinforced magnesium, failure strain was almost unchanged under tensile loading while it was reduced under compressive loading for both Mg/ZrO 2 and Mg/(ZrO 2 + Cu) composites.
2005
In the present study, magnesium based composites with three different volume percentages of nano-sized Al 2 O 3 particulates reinforcement were fabricated using blend-press-sinter methodology avoiding ball milling. Microstructural characterization of the materials revealed reasonably uniform distribution of nano-size Al 2 O 3 reinforcement and presence of minimal porosity. Mechanical properties characterization revealed that the presence of nano-Al 2 O 3 particulates as reinforcement lead to a simultaneous increase in hardness, elastic modulus, 0.2% yield strength, UTS and ductility of pure magnesium. The results revealed that the 0.2% yield strength, UTS and ductility combination of the magnesium nano-composites containing 0.66 and 1.11 vol% of alumina remained higher when compared to high strength magnesium alloy AZ91 reinforced with much higher amount of micrometer size SiC particulates. An attempt is made in the present study to correlate the effect of presence of nano-Al 2 O 3 as reinforcement and its increasing amount with the microstructural and mechanical properties of magnesium.
Effect of Alumina (Al2O3) Particles on The Mechanical Properties of Magnesium (Mg)
Al-Nahrain Journal for Engineering Sciences, 2019
In the present study, magnesium-based composites reinforced with different volume fractions (3, 5, 10, and 15) vol.% of micro sized Al2O3 particulates were fabricated by powder metallurgy technique which involves mixed, compacted and sintered. Powders were mixed by ball milling (without balls) for 6 hours at rotation speed 60 rpm. Then powder was compacted at 550 MPa and sintered at 530˚C for 2 hours. Microstructures of sintered composites have been investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) energy dispersive. SEM image of sinter samples exhibit good bonding between the magnesium matrix and the alumina. The microhardness and wear resistance of micro composites has been improved significantly compared to that of pure magnesium. Highest value of microhardness is 97 HV at the volume fraction of 10 vol.% Al2O3.