Mechanical Properties and Metallurgical Characterization of LM25/ZrO2 Composites Fabricated by Stir Casting Method (original) (raw)
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Metal–matrix composites (MMCs) are known as the most useful and high-tech composites in our world as well as aluminum (Al) as the best metal for producing these composites. Combining aluminum and zircon (ZrSiO 4) will yield a material with the best corrosive resistance and mechanical properties like strength at high temperatures. Also, the abrasive wear behavior of these composites will be improved. In the present investigation, a study on aluminum/zircon composites has been carried out. Micro-structures of these composites in powder metallurgy conditions show different size distribution of zircon with different proportions in the composite. Also, there is a case-study about density and compressive strength and hardness of aluminum/zircon composites. The green specimens prepared by isostatic pressing of prepared powders with different zircon percentages, were sintered at two temperatures. These specimens were then investigated by different physical and mechanical testing methods to observe in which conditions the best properties would be obtained. The most improved compression strength was obtained with the specimen including 5% of zircon sintered at 650 °C.
Mechanical Characterization of Al 6061-Zircon Particulate Composites
Today composite materials gained popularity in their improved properties over the traditional materials, like low density, good thermal resistance , better corrosion resistance and surface finish. The Aluminium based metal matrix composites have the wide applications in Automotive and defence industries due to some good properties like strength to weight ratio, more wear resistance. In the present work Al6061 Alloy taken as the matrix alloy and zircon as the reinforcement , stir casting method was chosen to develop this composite. The melt composites in the graphite crucible were stirred by the mechanical stirrer and immediately it was poured to the cast iron moulds. Different samples of 0,3,6,9, and 12% of zircon were produced. Casted Samples were machined to ASTM standards. The Properties like tensile strength, impact strength ,Hardness and wear rate of the developed composites were investigated. For the 9% of reinforcement it has been observed a significant improvement in strength, hardness and reduction in the wear rate.
IOP Conference Series: Materials Science and Engineering
Steel is used because of its high strength and toughness, but it has high density, therefore lighter material with comparable toughness is developed. One alternative is aluminum matrix composite with zirconia (ZrO 2) as the reinforcement with high fracture toughness. Al-9Zn-6Mg-3Si (wt. %) composites were developed with addition of 2.5, 5, and 7.5 vol. % ZrO 2 through squeeze casting. To improve toughness, the composite was solution treated at 450 o C for 1 h, then aged at 200 o C for 1 h. Materials characterization included Optical Emission Spectroscopy (OES), Rockwell B hardness testing, impact testing, fractography analysis, microstructure analysis using Optical microscope (OM) and Scanning Electron Microscope (SEM) / Energy Dispersive X-Ray Spectroscopy (EDS), as well as X-Ray Fluorescence (XRF). The results showed that the more ZrO 2 particles, the higher porosity and the lower the hardness and the impact values, both in as-cast condition and after ageing at 200 o C at 1 h.
Study on Mechanical Behaviour of Al-15Si-10Zn/x ZrO 2 Composites Synthesized by Stir Cast Method
Journal of Metallic Material Research , 2023
In this research, the microstructure and mechanical properties of Al-15Si-10Zn-xZrO 2 (x = 5, 7 and 10 wt.%) composites synthesized by the stir-casting process have been investigated. The matrix and composite samples were characterized using an X-ray diffraction test (XRD) and their microstructures were studied using optical microscopy and scanning electron microscopy (SEM). The microstructure of different phases was analyzed using energy-dispersive spectroscopy (EDS). The microstructure of the Al-15Si-10Zn/ZrO 2 composites consisted of coarse primary Si, needlelike eutectic Si, and Zn-rich phases, with ZrO 2 reinforcement particles distributed homogeneously in the composites. The micro-hardness and tensile properties of the matrix and composites were determined at room temperature. The results show significant improvements in the micro-hardness and tensile strength of the composites compared to the matrix alloy. The micro-hardness of the stir-cast composites increased by 24%, 44%, and 58% in the 5, 7, and 10 wt% ZrO 2 reinforcement composites, respectively. The ultimate tensile strength (UTS) of the 5, 7, and 10 wt% ZrO 2 composites increased by 17%, 30%, and 44%, respectively, compared to the matrix alloy. The increased content of ZrO 2 resulted in an increase in hardness, ultimate tensile and yield strengths and a decrease in ductility.
Materials, 2013
Alumina-zirconia (AZ) composites are attractive structural materials, which combine the high hardness and Young's modulus of the alumina matrix with additional toughening effects, due to the zirconia dispersion. In this study, AZ composites containing different amounts of zirconia (in the range 5-20 vol %) were prepared by a wet chemical method, consisting on the surface coating of alumina powders by mixing them with zirconium salt aqueous solutions. After spray-drying, powders were calcined at 600 °C for 1 h. Green bodies were then prepared by two methods: uniaxial pressing of spray-dried granules and slip casting of slurries, obtained by re-dispersing the spray dried granulates. After pressureless sintering at 1500 °C for 1 h, the slip cast samples gave rise to fully dense materials, characterized by a quite homogeneous distribution of ZrO 2 grains in the alumina matrix. The microstructure, phase composition, tetragonal to monoclinic transformation behavior and mechanical properties were investigated and are here discussed as a function of the ZrO 2 content. The material containing 10 vol % ZrO 2 presented a relevant hardness and exhibited the maximum value of K I0 , mainly imputable to the t → m transformation at the crack tip.
IJERT-Structural and Mechanical Properties of Zirconia Toughened Alumina (ZTA) Composites
International Journal of Engineering Research and Technology (IJERT), 2014
https://www.ijert.org/structural-and-mechanical-properties-of-zirconia-toughened-alumina-zta-composites https://www.ijert.org/research/structural-and-mechanical-properties-of-zirconia-toughened-alumina-zta-composites-IJERTV3IS20451.pdf The Zirconia toughened Alumina (ZTA) composites with 0-16 wt % of ZrO 2 were prepared by slurry method and sintered at temperature (T s) 1500°C and 1600°C for 2 hours. The density, porosity, structural properties and mechanical properties of Al 2 O 3-ZrO 2 composites with respect to ZrO 2 content as well as sintering temperature have been explored in the present work. About 2% higher density of 16 wt % ZTA has been achieved and the microstructures are highly homogeneous and finer with less porosity when compared to pure Al 2 O 3. The surface morphology of the samples was studied by using SEM. The effect of zirconia content on hardness and elastic modulus were investigated. At 1500°C, maximum hardness shows 15.79 GPa and at 1600°C, it is 19.76 GPa, which is observed for pure Alumina. However, at same temperatures, minimum hardness shows 11.24 GPa and 12.96 GPa, respectively, that is observed for 16 wt% ZrO 2. Elastic modulus also shows same behaviour as shown for hardness. Flexural strength increases with the increase of both zirconia content and sintering temperature. The approach adopted in the present study may provide an alternative to design Al 2 O 3-ZrO 2 composites with improved mechanical properties.
International Journal of Engineering Research and Technology (IJERT), 2019
https://www.ijert.org/preparation-and-microstructural-characterization-of-zro2-reinforced-al-6061-metal-matrix-composites https://www.ijert.org/research/preparation-and-microstructural-characterization-of-zro2-reinforced-al-6061-metal-matrix-composites-IJERTCONV7IS07001.pdf Aluminum Metal Matrix Composites have optimized mechanical properties like good resistance to wear, high strength to weight ratio etc. and hence plays a great role in the fields of automotive, aerospace and marine applications. In the present work an attempt is made to synthesize MMCs using 6061 Al as base metal matrix reinforced with Zirconia (ZrO2) using liquid metallurgy through stir casting method. The reinforcement addition level is varied from a range of 1 to 5 wt. % in levels of 2 wt. %. Reinforcement particles for each respective composite were preheated to about 150 0 C and then dispersed into molten Al6061. Scanning Electron Microscope is used to obtain micrographs for analysis of the composition and microstructural characterization. EDAX is used to find out composition of obtained test sample and phase analysis is carried out using XRD analysis.
Study of Mechanical Properties of LM-4 Reinforcement with ZrO 2 for Structural Application
Composite materials are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct within the finished structure. Composite materials are highly utilized in various fields like aerospace structure, marine, automobile, etc. The present study deals with the investigation of effect of reinforcement (Zirconium dioxide) particles on mechanical properties of Aluminium alloy (LM4) composites, fabricated by stir casting method. The MMC's specimens were prepared by varying weight fraction of the reinforced particles as 0 Wt.%, 3 Wt.%, 6 Wt.%, and 9 Wt.%, 12 Wt.%, 15 Wt.% and keeping all other parameters constant. The microstructure and mechanical properties of fabricated MMC's were analyzed. Microstructural studies of the MMC's reveal a uniform distribution of zirconium dioxide (ZrO2) particles in the Aluminium (LM4) matrix. The mechanical properties like Micro structural properties, Hardness, Tensile strength and Compression test, were improved with the increase in weight fraction of zirconium dioxide particles in the Aluminium matrix. It was observed that the elongation decrease with increase weight fraction of zirconium dioxide particles in the Aluminium matrix.
The present study deals with the evaluation of mechanical properties of aluminium alloy (Al6061) metal matrix composites reinforced with fused zirconia alumina (ZA-40) bonded abrasive particles which were fabricated by stir casting method. The sample specimens were prepared by varying the percentage of weight fraction of reinforced particles as 5,10,15 and the remaining aluminium alloy respectively. The mechanical properties were analysed. The evaluation of mechanical properties indicates variations in tensile strength, hardness and impact strength with respect to composite combinations. From the experimental studies, the optimum weight percentage of the matrix and reinforcement on the basis of mechanical properties was found to be 90 and 10 respectively.