Advances in Materials and Processing Technologies Low cost manufacturing of aluminium-alumina composites (original) (raw)
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Co-continuous aluminaealuminum composite materials with excellent physical and mechanical properties offer great potentials for lightweight, wear resistant, and high-temperature applications. They combine metallic properties of matrix alloys (ductility and toughness) with ceramic properties of reinforcements (high strength and high modulus), leading to greater strength in shear and compression and higher service-temperature capabilities. Composite materials prepared from a liquid-phase displacement reaction present a unique microstructure in which each phase is a continuous network penetrated by the network of the other constituent. In this study, aluminumealumina matrix composites reinforced with glass bubbles with low thermal and electrical conductivities are presented. Different characterization techniques were used to determine physicalemechanical properties. Porosity and density measurements were carried out by means of helium gas pycnometer and basic materials parameters were compared such as effect of the sintering process, thermal conductivity, and percentage of the wax. Drop weigh tests, semi static compression tests and also scratch tests were applied to measure the general mechanical and damage behavior of these composites. Microstructural and fracture behavior were evaluated by Scanning Electron Microscopy (SEM). A three dimensional non-linear finite element model was developed for modeling the impact and compression behavior of alumina reinforced aluminum matrix composite materials. For this stage, ABAQUS/Explicit commercial program was used. The finite element results have shown a good correlation with the experimental data in terms of contact-force and energy histories and also deflection phenomena of the alumina reinforced aluminum matrix composites during the impact was observed between the experimental data.
Tensile properties of in-situ aluminium–alumina composites
Materials letters, 2005
Aluminium–alumina particle composite was fabricated by in-situ method. Alumina particles were produced from reduction of copper and silicon oxides by melting and casting aluminum through a squeeze cast system. Four composite specimens with varying amounts of alumina and different compositions were prepared for tensile tests. Corresponding to each composite specimen, a non-composite alloy with the same chemical composition was also produced under identical conditions for comparison. Tensile tests were carried out at room and higher temperatures. The tensile strength of composites at 300 °C improved significantly as compared to the same alloys without alumina particles.
Processing, microstructure, and properties of co-continuous alumina-aluminum composites
Materials Science and Engineering: A, 1995
A novel co-continuous composite of AI203 and AI has been developed, consisting of approximately 65% (by volume) of the ceramic phase. It is formed by a liquid phase displacement reaction, involving the displacement of Si from SiO 2 and its replacement by Al. A model for the formation mechanism is presented, based on the reaction thermodynamics and the associated experimentally deter° mined transformation kinetics. It is shown that the process is essentially near-net shape, in which the features of the SiO 2 precursors are faithfully reproduced in the composie product. Various physical and mechanical properties that are exhibited by this composite have been determined and are presented.
Fabrication of in situ aluminum–alumina composite with glass powder
Journal of Alloys and Compounds, 2009
The in situ methods have been developed in production of aluminum matrix composites. A commonly adopted in situ method involves reaction between a metal oxide and aluminum to produce alumina particles or whisker reinforcements. By completing the alumina formation reaction, the reduced metal usually further reacts with Al to form intermetallic phases, which also act as reinforcements in the matrix of the composite. In this work, CuO and amorphous SiO2 (glass powder) were introduced into pure Al melt to produce Al–Al2O3 in situ composites. Aluminum matrix composites were formed by dissolution of Cu and Si alloying elements and alumina particles. The size and shape of alumina particles were studied by scanning electron microscopy (SEM). Mechanical properties of obtained composites were evaluated with tensile tests. The size of alumina obtained from mixture of SiO2 and CuO was bigger than the alumina particles obtained from CuO.
Processing and microstructure of alumina-based composites
Journal of Materials Engineering and Performance, 1999
A study of powder structure and its effect on the sintering tendency of certain alumina-based ceramic systems, that is, Al 2 O 3 -SiO 2 and Al 2 O 3 -ZrO 2 , was carried out to improve their mechanical strength and fracture toughness. The compacting behavior and the sintering characteristics were optimized through control of various parameters such as composition, compaction pressure, sintering temperature, and time. Best densification was obtained for mixtures prepared using very fine and deagglomerated alumina powders.
Effect of ceramic additives on mechanical properties of alumina matrix composites
International Journal of Microstructure and Materials Properties, 2012
Till today several kinds of ceramics and ceramic matrix composites are developed for extreme environmental conditions. Most of these ceramics have microstructures with relatively "big" crystals, having high rigidness and strong inclination to nick, pitting and rigid fractures, so they are not usable for collision with metallic or other bodies under high speeds like 800 m/sec or more. On the basis of several years experiments in development and testing of ceramic materials and corundum matrix composites the authors successfully developed new alumina-matrix composite materials reinforced with Si 2 ON 2 , SiAlON, AlN and Si 3 N 4 . These new alumina based ceramic matrix composites were tested under collisions with different metallic bodies having high densities and speeds higher than 800 m/sec. During the collisions the kinetic energy of flying metallic objects distributing to fracture energies, heatings and recrystallizations both of ceramic and metallic bodies. In the centres of collisions, where oxygen was absent, the authors have found new, high density "diamond-like Si 3 N 4 " materials with cubic crystals, where nitrogen atoms distributed in the centres of the cubes. These new crystal structures of Si 3 N 4 in the alumina matrix have extreme dynamic strength and hardness, like diamond. Having surplus of oxygene in the centres of collisions this new "diamond-like Si 3 N 4 " was not observed, when a very strong oxydation of metallic bodies was taken place. Using the energy conception of collision, the authors mathematically described the energy engorgements of destruction of ceramic materials and heating of participating bodies as well as energy engorgement used for the phase transformations of ceramic and metallic particles during their collision.
Metallurgical and Materials Transactions A, 2021
Squeeze casting and powder metallurgy techniques were employed to fabricate AlSi12/Al2O3 composites, which are lightweight structural materials with potential applications in the automotive industry. The impact of the processing route on the material properties was studied. Comparative analyses were conducted for the Vickers hardness, flexural strength, fracture toughness, thermal conductivity, thermal residual stresses, and frictional wear. Our results show that the squeeze cast composite exhibits superior properties to those obtained using powder metallurgy.
Processing, Microstructure and Properties of Micro and Nano Alumina Reinforced Aluminium Composites
2013
We express our sincere gratitude to Dr. B. C. Ray, Head of the Department (HOD), Metallurgical and Materials Engineering, NIT Rourkela for giving us an opportunity to work on this project and allowing us access to valuable facilities in the department. We avail this opportunity to express our indebtedness to our guide Dr.A.K.Mondal, Department of Metallurgical and Materials Engineering, NIT Rourkela, for his valuable guidance, constant encouragement and kind help at various stages for the execution of this dissertation work. We are grateful to the entire faculty of Metallurgical and Materials Engineering Department for providing the facilities and necessary discussions required for our project work.
Mechanical properties and wear strengths in aluminium-alumina composites
Materials and Structures, 1998
In this study, after producing metal matrix composite materials reinforced with ceramic particles by adding hard A120 3 particles into a selected ageable aluminum alloy, the wear strengths were investigated. Composites of aluminum alloys containing 2 to 10 wt ofA1203 particles in the size range of 23.4 to 108/.tm were prepared by adding alumina particles to a partially-solid vigorouslyagitated matrix alloy. For a given tribologic system, the sizes and ratios of optimum particles were determined from the point of the wear strengths of these materials, of which the wear strengths greatly increased according to the matrix materials. Alumina particles were subjected to preheating at 500~ for 8 hours. Particles were added into the alumina alloy heated up to semi-solid/ semi-liquid phase interval in an argon medium by using a mixer. Then furnace temperature was raised up to 800~ step by step. Later the composite materials were die cast and solidified and aged. The behavior of the composites was studied by using a pin-on-disk type machine. The largest wear strengths were obtained at an average particle size of 76.5 btm and percentage of 4% wt A120 3. Increase in the wear strength of the composites was obtained as 3.85 times the wear strength of the matrix material. Apt& avoir fabriqu~ des mat&iaux composites h matrice m~tallique, renforc& de particules c&amiques, par l'ajout de particules dures d'Al203 clans un alliage d'aluminium soumis au vieillissement, on a conduit une ~tude sur burs r&istances a l'usure. Des composites d'alliages en aluminium, ayant une teneur de 2 h 10% (en poids) de particules d'Al203 de dimensions allant de 23,4 h 108 ~tm, ont ~t~ pr~par& par l'ajout de particules d'alumine h une matrice d'alliage partiellement solid~& et vigoureusement agit&. Pour un sysbme tribologique donn~, les dimensions et les taux optimaux des particules ont ~t~ d&rmin& sur la base des r&istances a l'usure des mat&iaux en question, dont les r&istances se sont accrues de mani&e signfcative selon les matMaux des matrices. Les particubs d' alumine ont ~t~ soumises hun pr&hauffage a 500 ~ pendant 8 heures. Ensuite, elles ont Ot~ ajout&s a l'alliage alumine, pr&lablement chauff~ jusqu'a la phase semi-solide/semi-liquide dam un milieu d'argon, au moyen d'un malaxeur. Ensuite, la temp&ature du four a ~tO augment& par paliers jusqu'h 800 ~ Plus tard, les mat&iaux composites ont ~t# coulds sous pression, soli-dr& et vieillis. Le comportement des composites a ~t~ ~tudiO sur une machine d' essai a l' usure. Les meilleures r&istances a l' usure ont {t~ obtenues avec une particule ayant une dimension moyenne de 76,5 btm, a une teneur de 4 % (en poids) de Al203. L'accroissement de la r&istance des composites obtenue ~tait de 3,85 sup&ieur a la r&'stance de la matn'ce.
Influence of alumina percentage on hot deformation of aluminium–alumina matrix composite
International Journal of Cast Metals Research, 2014
Aluminium-alumina Al-Al 2 O 3 metal matrix composites were fabricated using the powder metallurgy techniques and ex situ casting. Different reinforcement volume fractions were used, that is, 0, 6, 10 and 18 vol.-% Al 2 O 3. The effect of percentage of alumina particles was investigated through hot tensile deformation conducted at 773 K temperature. Scanning electron microscopy was used to study the microstructure of the produced composite. The tensile strength of the Al-Al 2 O 3 was found to improve as a function of reinforcement volume fraction. With the exception of Al-18 vol.-%Al 2 O 3 , the metal matrix composite showed better strength and behaviour at high temperature of the test than the unreinforced matrix.