Consolidation Features of Aluminum-Alumina Compositions by Powder Metallurgy Methods

2016 ◽  
Vol 254 ◽  
pp. 110-115
Author(s):  
Mihai Ovidiu Cojocaru ◽  
Mihaela Raluca Condruz ◽  
Florică Tudose
Keyword(s):  
Solid Phase ◽  
Particle Diameter ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Average Particle ◽  
Matrix Composites ◽  
Aluminum Particles ◽  
Transmission Electron ◽  
Tapped Density ◽  
Powder Metallurgy Methods

In this paper was followed the processing flow of aluminum-alumina compositions (10÷20% alumina) in powder state, aiming to obtain aluminum matrix composites reinforced with alumina particles, starting from selecting and mixing the grading fraction of both components reaching up to sintering; it was analyzed the way in which reflects the variation of grading fraction ratio (expressed through average particle diameter in the analyzed fractions limits) on the level of technological interest features: apparent density, tapped density, flowability, presability and on densification after sintering (in various environments). By transmission electron microscopy was observed that aluminum particles showed on the surface a nanoscale oxide film, so the sintering occurs between congeneric areas – by solid phase sintering mechanisms [1, 2, 3]. The analysis of thermophysical properties revealed a decrease of thermal diffusivity at an increase of alumina, simultaneous with the decrease of the densification level.

Dislocation Character and Evolution Mechanism of Particles Reinforced Aluminum Matrix Composites Impacted by Pulsed Electromagnetic Field

2013 ◽  
Vol 575-576 ◽  
pp. 406-409 ◽  
Author(s):  
Xue Ting Yuan ◽  
Guirong Li ◽  
Hong Ming Wang ◽  
Yun Cai ◽  
Yu Tao Zhao ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Aluminum Matrix ◽  
Structural Evolution ◽  
Elastic Interaction ◽  
Dislocation Nucleation ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Transmission Electron ◽  
Dislocation Movement ◽  
Pulsed Electromagnetic

Under the condition of different magnetic induced intensity as1.5T, 2.0T and2.5T, AlTiZr particles reinforced 7055 aluminum matrix composites were subject to the magnetic impact processing. The structural evolution was observed by transmission electron microscope. The result shows that, magnetic impact processing can induce dislocation with different morphologies and increase the dislocation density. The enhancement of dislocation density and elastic interaction between them can cause the resistance of dislocation movement and improve the strength of material. The magnetic pressure may exceed the yield strength of special orientation crystal. The increased temperature induced by heat effect will lower the yield point further. It is useful to dislocation nucleation and movement.

Microstructure and Properties of SiC Particle Reinforced Aluminum Matrix Composites by Powder Metallurgy Method

2013 ◽  
Vol 457-458 ◽  
pp. 131-134 ◽  
Author(s):  
Tao Fan ◽  
Cong Li Xiao ◽  
Yan Rong Sun ◽  
Hong Bo Li
Keyword(s):  
Particle Size ◽  
Wear Resistance ◽  
Powder Metallurgy ◽  
Sintering Temperature ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Average Particle ◽  
Particle Sizes ◽  
Matrix Composites ◽  
Sic Particle

The aim of this study is to investigate the effect of SiC particle pretreatment, aluminum matrix particle size and sintering temperature on relative density, hardness, microstructure and wear resistance to SiC particle einforced aluminum matrix composites. To this end, the amount of 16.7 wt.% SiC with average particle sizes 20μm was used along with pure aluminum of average particle size of 75 μm and 25μm. Powder metallurgy is a method used in the fabrication of this composite in which the powders were mixed using a planetary ball mill. By analyzing SEM micrograph and the Property test, it is concluded that SiC particle pretreatment has significant effect on the morphology of pecimens. pretreatment increase the interface adhesion, improve the wettability. SiC is uniformly distributed in the matrix, with good relation to the substrate, the maximum hardness is 51.1HB, the minimum wear rate is 0.1684%, while the density is 97.3%.For the same SiC content and particle size, the smaller the particle size of aluminum matrix is, the higher wear resistance of composite materials is on condition that others are same, the higher sintering temperature and the higher the wearability of composites, the wear resistance of the composite material is significantly improved after SiC pre-processing.The relative density increases with increasing aluminum matrix particle sizes under the same pressure and the holding time. The actual density of all samples reached the theoretical density over 96%, to a maximum of 98.9%.

Microstructure and Properties of In Situ Fabricated Al-5wt.%Si-Al2O3 Composites

2012 ◽  
Vol 567 ◽  
pp. 15-20 ◽  
Author(s):  
Ling Cheng ◽  
De Gui Zhu ◽  
Ying Gao ◽  
Wei Li ◽  
Bo Wang
Keyword(s):  
Shear Strength ◽  
Liquid Phase ◽  
Solid Phase ◽  
Hold Time ◽  
Aluminum Matrix ◽  
Liquid Phase Sintering ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
X Ray

Alumina reinforced aluminum matrix composites (Al-5wt.%Si-Al2O3) fabricated by powder metallurgy through hot isotactic pressing were sintered in different processes, i.e. solid and liquid phase sintering. Optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscope (SEM), Energy Dispersive X-ray (EDX) techniques were used to characterize the sintered composites. The effects of solid phase and liquid phase sintering on density, microstructure, microhardness, compression and shear strength were investigated. It was found that in situ chemical reaction was completed in solid phase sintering, but the composites had lower microhardness, comprehension and shear strength due to low density and segregation of alumina and Si particles in microstructure. Segregation of reinforcement particles in solid phase sintering resulted from character of solid reaction and Si diffusion at high temperature over a long hold time.

Fabrication of Al-AlN Nanocomposites

2016 ◽  
Vol 684 ◽  
pp. 302-309 ◽  
Author(s):  
Aleksandr P. Amosov ◽  
Y.V. Titova ◽  
I.Y. Timoshkin ◽  
Antonina A. Kuzina
Keyword(s):  
Aluminum Nitride ◽  
Molten Aluminum ◽  
Solid Phase ◽  
Aluminum Matrix ◽  
Physical And Mechanical Properties ◽  
Ex Situ ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
High Temperature Synthesis ◽  
Molten Aluminum Alloy

A review of the methods of obtaining and properties of aluminum matrix composites, discretely reinforced with ceramic particles and nanoparticles of aluminum nitride AlN, is given. The survey shows that at low weight, nanocomposites Al-AlN possess improved physical and mechanical properties, including at high temperatures up to 400-550°C, which makes them very attractive for applications in automotive, aerospace and semiconductor technology. However, due to the long duration and energy consumption, expensive and complicated equipment, low productivity of existing solid-phase methods of powder metallurgy and liquid-phase metallurgical processes of fabrication of nanocomposites of Al-AlN, there are not yet the mastered technologies of industrial production of these composites. Azide technology of self-propagating high-temperature synthesis (SHS-AZ) using sodium azide NaN3 as a solid nitriding reagent allows you to get relatively inexpensive nanopowder of aluminum nitride in the form of nanofibers along with side salt of cryolite Na3AlF6, which can play the role of flux when working with molten aluminum. A new simple ex-situ method of introduction of AlN particles in the molten aluminum alloy in the form of a composite master alloy obtained by fusing together a flux carnallite KCl·MgCl2 with AlN nanopowder mixed with cryolite Na3AlF6 was proposed. Results of experiments on the application of the proposed method for obtaining nanocomposite with matrix made of aluminum-magnesium alloy AlMg6 containing up to 1 % of the reinforcing phase AlN are presented.

Mechanical properties of Al-Cu/B4C and Al-Mg/B4C metal matrix composites

2021 ◽  
Vol 63 (4) ◽  
pp. 350-355
Author(s):  
Mehmet Ayvaz ◽  
Hakan Cetinel
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Liquid Phase ◽  
Oxide Layer ◽  
Solid Phase ◽  
Aluminum Matrix ◽  
Liquid Phase Sintering ◽  
Aluminum Matrix Composites ◽  
Powder Metallurgy Method ◽  
Matrix Composites

Abstract To be able to successfully produce ceramic-reinforced aluminum matrix composites by using the powder metallurgy method, the wetting of ceramic reinforcements should be increased. In addition, the negative effects of the oxide layer of the aluminum matrix on sinterability should be minimized. In order to break the oxide layer, the deoxidation property of Mg can be used. Furthermore, by creating a liquid phase, both wettability and sinterability can be improved. In this study, the effects of Mg and Cu alloy elements and sintering phase on the wettability, sinterability, and mechanical properties of Al/B4C composites were investigated. For this purpose, various amounts (5, 10, 20, and 30 wt.-%) of B4C reinforced Al5Cu and Al5Mg matrix composites were produced by the powder metallurgy method. After pressing under 400 MPa pressure, composite samples were sintered for 4 hours. The sintering was carried out in two different groups as solid phase sintering at 560 °C and liquid phase sintering at 610 °C. Despite the deoxidation effect of Mg in Al5Mg matrix composites, higher mechanical properties were determined in Al5Cu composites which were sintered in liquid phase because wettability increased. The highest mechanical properties were obtained in the 20 wt.-% B4C reinforced Al5Cu sample sintered in liquid phase.

scholarly journals Hardness and Microstructure of Mixed Al-CNF Powder Extrusion

2017 ◽  
Vol 62 (2) ◽  
pp. 1267-1270
Author(s):  
D.-H. Kim ◽  
T.-J. Kim ◽  
S.-G. Lim
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Aluminum Powder ◽  
Average Particle Size ◽  
Aluminum Matrix ◽  
Hot Extrusion ◽  
Aluminum Matrix Composites ◽  
Average Particle ◽  
Matrix Composites

AbstractIn this study, mechanical properties and microstructures of extruded aluminum matrix composites were investigated. The composite materials were manufactured by two step methods: powder metallurgy (mixture of aluminum powder and carbon fiber using a turbular mixer, pressing of mixed aluminum powder and carbon fiber using a cold isostatic pressing) and hot extrusion of pressed aluminum powder and carbon fiber. For the mixing of Al powder and carbon fibers, aluminum powder was used as a powder with an average particle size of 30 micrometer and the addition of the carbon fibers was 50% of volume. In order to make mixing easier, it was mixed under an optimal condition of turbular mixer with a rotational speed of 60 rpm and time of 1800s. The process of the hot-extrusion was heated at 450°C for 1 hour. Then, it was hot-extruded with a condition of extrusion ratio of 19 and ram speed of 2 mm/s. The microstructural analysis of extruded aluminum matrix composites bars and semi-solid casted alloys were carried out with the optical microscope, scanning electron microscope and X-ray diffraction. Its mechanical properties were evaluated by Vickers hardness and tensile test.

scholarly journals Investigation of Mechanical Properties of Al7Si/ SiC and Al7SiMg/SiC Composites Produced by Semi Solid Stir Casting Technique

2018 ◽  
Vol 159 ◽  
pp. 02036
Author(s):  
Sulardjaka ◽  
Sri Nugroho ◽  
Suyanto ◽  
Deni Fajar Fitriana
Keyword(s):  
Mechanical Properties ◽  
Average Particle Size ◽  
Aluminum Matrix ◽  
Stir Casting ◽  
Reinforcement Particle ◽  
Aluminum Matrix Composites ◽  
Average Particle ◽  
Matrix Composites ◽  
Casting Technique ◽  
Semi Solid

Mechanical characteristic of silicon carbide particle reinforced aluminum matrix composites produced by semi solid stir casting technique was investigated. Al7Si and Al7SiMg were used as metal matrix. High purity silicon carbida with average particle size mesh 400 was used as reinforcement particle. Aluminum matrix composites with variation of SiC: 5 %, 7.5 % and 10 % wt were manufactured by the semi solid stir casting technique. Stiring process was performed by 45 ° degree carbide impeller at rotation of 600 rpm and temperature of 570 °C for 15 minutes. Characteritation of composites speciment were: microscopic examination, density, hardness, tensile and impact test. Hardness and density were tested randomly at top, midlle and bottom of composites product. Based on distribution of density, distribution of hardness and SEM photomicrograph, it can be concluded that semisolid stir casting produces the uniform distribution of particles in the matrix alloy. The results also indicate that introducing SiC reinforcement in aluminum matrix increases the hardness of Al7Si composite and Al7SiMg composite. Calculated porosities increases with increasing wt % of SiC reinforcements in composite. The addition of 1 % Mg also increases the hardness of composites, reduces porosities of composite and enhances the mechanical properties of composites.

scholarly journals Al-AlN nano-structural aluminum-matrix composite manufacturing by powder metallurgy method

2019 ◽  
Vol 2019 (10) ◽  
pp. 3-11
Author(s):  
Александр Амосов ◽  
Aleksandr Amosov ◽  
Антонина Кузина ◽  
Antonina Kuzina ◽  
Юлия Титова ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Solid Phase ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composite ◽  
Nano Particles ◽  
Phase Method ◽  
Aluminum Matrix Composites ◽  
Powder Metallurgy Method ◽  
Matrix Composites ◽  
Solid Phase Method

According to the review of liquid-phase and solid-phase methods of manufacturing aluminum-matrix composites reinforced with ceramic nano-particles one can obtain cast composites having a reinforcing phase not more than 5% by weight. There is shown a possibility to manufacture Al-AlN nano-composite with considerably higher content (up to 30% by weight) AlN aluminum nitride nano-particles with the aid of a solid-phase method of powder metallurgy.

Using explosive energy for processing aluminum matrix composites

2000 ◽  
Vol 10 (PR9) ◽  
pp. Pr9-119-Pr9-122
Author(s):  
V. Popov ◽  
V. Gulbin ◽  
E. Sungurov
Keyword(s):  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Explosive Energy
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