Mechanical Properties and Microstructure of Mg∕SiC Nanocomposites Fabricated by Ultrasonic Cavitation Based Nanomanufacturing (original) (raw)
Related papers
2006
This NIRT research program is to advance both the fundamental understanding and knowledge of ultrasonic cavitation based solidification processing of complex bulk Mg MMNC materials/components and their processing/structure/property relationships. Cast bulk Mg alloy matrix nanocomposites can have a widespread impact on the automobile and aerospace industries by significantly improving the vehicle energy efficiency and performance. One of the major tasks of this NIRT program is to characterize the micro/nano structure of the resultant nanocomposites. The dislocation structure in the matrix around nanoparticles will be examined to understand the mechanism of strengthening by nanoparticles.
International Journal of Metalcasting, 2008
Magnesium based metal matrix composites (MMCs) have been extensively studied as an attractive choice for automotive and aerospace applications due to their low density and superior specific properties including strength, stiffness and creep resistance. Xi et al [1] studied the Ti-6Al-4V particulate (TAp) reinforced magnesium matrix composite which is fabricated by powder metallurgy route. The tensile strength of the composite was markedly higher than that of the unreinforced magnesium alloy. Xi et al [2] also studied the SiC whiskers-reinforced MB15 magnesium matrix composites by powder metallurgy and found that the mechanical properties of SiCw/MB15 composite were significantly influenced by powder-mixing methods of PM. Li et al [3] studied the hot deformation behavior of SiC whiskers reinforced AZ91 magnesium matrix composites in compression. It was found that the microstructure evolutions involved the movement of SiC whiskers and the changes of the matrix, and the rotation and the broken SiC whiskers tended to be obvious with the increasing strain, and also high density of dislocation was observed in the AZ91 matrix at the initial stage of compression (1%). Jiang et al [4] studied that magnesium metal matrix composites (MMCs) reinforced with B4C particulates fabricated by powder metallurgy. The hardness and wear resistance of the composites were higher than those of as-cast Mg ingot and increased with increasing amount of B4C particulates from 10 to 20 vol.%. Zhang et al [5] studied that carbon nanotube reinforced magnesium metal matrix composite by stirring the carbon nanotube into magnesium melts. It was found that carbon nanotube, especially chemical nickel-plated one, This paper presents the results from our recent development in cast bulk Mg nanocomposites. SiC nanoparticles reinforced magnesium and magnesium alloys including pure magnesium, and Mg-(2, 4)Al-1Si and Mg-4Zn were successfully fabricated by ultrasonic cavitation based dispersion of SiC nanoparticles in magnesium melt. As compared to un-reinforced magnesium alloy matrix, the mechanical properties including tensile strength and yield strength were improved significantly while the ductility was retained or even improved. In the microstructure, the grain size was refined considerably by SiC nanoparticles. While some micro SiC clusters still exist in the magnesium matrix, ultrasonic cavitation based processing is very effective in dispersing SiC nanoparticles. A SEM study showed that SiC nanoparticles were dispersed quite well in the areas outside micro SiC clusters. A TEM study on the interface between SiC nanoparticles and magnesium alloy matrix indicates that SiC nanoparticles bonded well with Mg matrices without forming an intermediate phase.
Ultrasonic Assisted Fabrication of Magnesium Matrix Composites: A Review
Materials Today: Proceedings, 2017
Magnesium matrix composite is one of the most promising materials to meet the increasing demands for high performance and lightweight materials for structural applications. Development of manufacturing techniques suitable for commercial production of bulk Mg-composites remains technological challenges. In the last decade, ultrasonic cavitation assisted stir casting has emerged as the most versatile technique for fabrication of Mg-matrix composites, specifically nanocomposites. The state of the knowledge related to the processing, microstructural evolution and mechanical properties of Mg-composites prepared by this method is presented here with specific emphasis on highlighting the effects of amount, size and distribution of reinforcements.
Advanced Engineering Materials, 2020
A quantitative understanding of the role of ultrasonic treatment process variables on microstructure and mechanical properties is critical for the development of process maps for manufacturing metal matrix composites. This paper presents a novel mathematical framework to delineate the functional correlations between ultrasonication time, grain refinement, and hardening in SiC nanoparticle reinforced Al matrix composites. Ultrasonic treatment generates microbubbles and deagglomerates SiC to increase heterogeneous nucleation sites synergistically. The increase in volumetric nucleation density due to SiC addition exhibits slow exponential kinetics with varying ultrasonication time. An outstanding grain refinement efficiency of 62.8% is achieved upon ultrasonication for 90 s. The contributions to an increase in the hardness due to grain refinement and SiC dispersion are isolated to develop correlations between ultrasonication time and hardening. Hardening increases exponentially with treatment time due to the reduction of interparticle distance from sonication induced SiC dispersion. These fundamental mathematical correlations constitute a significant advancement towards the development of ultrasonic process maps and metal matrix composite manufacturing technology.
Ultrasonication Assisted Fabrication of Aluminum and Magnesium Matrix Nanocomposites -A Review
Recent researches in the domain of casting confirmed that the mechanical properties of metal based nanocomposites such as Al and Mg can be appreciably enhanced when ultrasonic cavitation assisted solidification processing is used. Ultrasonic vibrations infused solidification technique is used for the manufacturing of aluminum and magnesium alloy metal matrix nanocomposites, with nano sized ceramic particles used as reinforcing agents. In this solidification processing, mitigation of clusters have been observed and the reinforcing agents were dispersed randomly in aluminum and magnesium matrix nanocomposites. The ultrasonic assisted casting approach will manage the grain dimensions via minimizing agglomeration of nano particles in metal matrices. This paper opinions the properties and morphology of aluminum and magnesium based metal matrix nanocomposites fabricated through ultrasonic assisted casting process.
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.
Effect of ultrasonic treatment on microstructural and mechanical properties of Al 7075/Grp composite
Materials Chemistry and Physics, 2022
Magnesium alloys are important light metals. In recent years, they have been widely applied in the aerospace and automotive industries, and in the manufacture of communication devices, consumer-electronics appliances and computer products. However, cast magnesium and magnesium alloys are subject to problems due to gas pores, inclusion particles, oxide films, and so on. How to reduce the harm caused by these defects and refine the structure to improve casting quality has become an important topic. In this study, we evaluate the effect on casting quality of an ultrasonic method for treating the melt. The method is based on the generation of cavitation bubbles from ultrasonic treatment of the melt, which induces dispersion and degassing action. Analysis of the microstructure and determination of the mechanical properties of the resultant castings are the basis for identifying the quality of the magnesium and magnesium alloys. The microstructure was evaluated using an optical microscope and scanning electron microscopy (SEM). The elemental constituents of the inclusion particles and oxide films were identified using scanning electron microscopy in conjunction with an X-ray energy dispersive spectrometer and electron probe microanalyzer (EPMA). Finally, the mechanical properties of the magnesium and magnesium alloys, including the tensile strength, the elongation and the hardness, were also determined and discussed. In addition, variations in mechanical properties of cast aluminum and magnesium alloys by ultrasonic treatment are also discussed.
Workability and mechanical properties of ultrasonically cast Al–Al2O3 nanocomposites
Materials Science and Engineering: A, 2012
Workability and mechanical properties of the ultrasonically cast Al-X wt% Al 2 O 3 (X¼ 2, 3.57 and 4.69) metal matrix nanocomposites were reported in the present investigation. The Al-Al 2 O 3 (average size $ 10 nm) composites showed maximum reduction ratios of 2, 1.75 and 1.41 at room temperature, and 8, 7 and 6 at 300 1C. The elastic modulus, nanoindentation hardness, microhardness and Vickers hardness were measured on the as-cast, cold and hot rolled specimens. The tensile properties were also evaluated for the as-cast composites for different wt% of reinforcement. The microstructural examination was done by optical, scanning and transmission electron microscopy. The strength and workability of the nanocomposites were discussed in the light of dislocation/particle interaction, particle size and its concentration, inter-particle spacing and working temperature. 2 wt% of Al 2 O 3 reinforcement showed better combination of workability and mechanical properties possibly due to better distribution of particulates in the matrix.
Mechanical and physical properties of selected magnesium base nanocomposites
IOP Conference Series: Materials Science and Engineering, 2018
The effect of various nanoparticles (BN, Al2O3, ZrO2, Gr) on the mechanical and physical properties of magnesium was studied in the present paper. Microcrystalline magnesium reinforced with nanoparticles was prepared by ball milling and hot extrusion. Microhardness of samples was measured at room temperature. The linear thermal expansion of the nanocomposites was measured over a wide temperature range from RT up to 400°C. Dynamic modulus and amplitude dependent internal friction were measured at room temperature. Although all nanocomposites were prepared with the same technology substantial differences in mechanical and physical properties were estimated among various nanocomposites. Bonding between magnesium matrix and ceramic and graphite nanoparticles plays important role for the resulting nanocomposites properties.