Interfaces in a slowly cooled Al-SiC composite

1990 ◽  
Vol 48 (4) ◽  
pp. 380-381
Author(s):  
Asgeir Bardal ◽  
Ragnvald Høier
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Dislocation Density ◽  
Physical Properties ◽  
Local Structure ◽  
Room Temperature ◽  
Al Alloy ◽  
Unreinforced Alloy ◽  
Heat Treated ◽  
The Matrix

In various metal-based composites ceramical powders are added for increased mechanical properties. Commercial materials are made through different production routes and in all cases the physical properties are determined by the production determined microstructure, i.e. by the grain and particle size, the dislocation density and the local structure near and at the interface between the matrix and the ceramical powder. In the present studies it has been focused on the two latter aspects.The matrix of the material investigated is the commercial Al alloy AA6061, with Mg and Si as the major alloying elements, and the powder added is SiC. The material has been subject to various heat-treatments and is being studied by use of TEM, EELS and EDS. In this work we will focus on material produced via a powder route, and specimens which have been heat treated at 400°C for 8 hours, extruded, slowly cooled (l°C/min) down to 180°C and then quenched to room temperature. This gives a material with good ductility, strength a little lower than the unreinforced alloy and a stiffness which is about 50% higher.

The effect of ageing duration on the mechanical properties of Al alloy 6061-garnet composites

2001 ◽  
Vol 215 (2) ◽  
pp. 113-119
Author(s):  
S C Sharma
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Al Alloy ◽  
Destructive Testing ◽  
Transmission Electron ◽  
Heat Treated ◽  
The Matrix ◽  
Reinforcing Particle ◽  
Alloy 6061

A well-consolidated composite of Al alloy 6061 reinforced with 4, 8 and 12 wt% garnet was prepared by a liquid metallurgy technique, the composite was heat treated for different ageing durations (T6 treatment), and its mechanical properties were determined by destructive testing. The results of the study indicated that, as the garnet particle content in the composites increased, there were marked increases in the ultimate tensile strength, compressive strength and hardness but there was a decrease in the ductility. There was an improvement in the tensile strength, compressive strength, and hardness with ageing due to precipitation. Precipitation in Al alloy 6061, with and without garnet particulate reinforcement, was studied using transmission electron microscopy. The fracture behaviour of the composites was altered significantly by the presence of garnet particles and the crack propagation through the matrix, and the reinforcing particle clusters resulted in final fracture.

Effects of Particle Size and Distribution on the Microstructure and Mechanical Properties of SiC Reinforced Al-30Si Alloy Composite

2012 ◽  
Vol 271-272 ◽  
pp. 12-16 ◽  
Author(s):  
Zeng Lei Ni ◽  
Ai Qin Wang ◽  
Jing Pei Xie
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Tensile Strength ◽  
Physical Properties ◽  
Combined Effects ◽  
Alloy Composite ◽  
Microstructure And Mechanical Properties ◽  
Sic Particles ◽  
The Matrix ◽  
Sic Particle

This paper studied the combined effects of particle size and distribution on the mechanical properties of the SiC particle reinforced Al-30Si alloy composites. The microstructure of experimental material was analyzed by SEM, the tensile strength and physical properties were examined. The results show that, with the increase of the SiC particle size in the composites, the clustering degree of the SiC particles decreases in the matrix, the SiC particles distribute more ununiformly. The tensile strength is influenced by the SiC particle size, the tensile strength of the composite reinforced by 13μm sized SiC particles is the highest.

Improvement of Mechanical Properties by Two-Step Aging in Ultrafine Grained Al-Ag-Sc Alloy

2014 ◽  
Vol 794-796 ◽  
pp. 857-863
Author(s):  
Daisuke Terada ◽  
Yan Zeng ◽  
Nobuhiro Tsuji
Keyword(s):  
Mechanical Properties ◽  
Grain Boundaries ◽  
Tensile Elongation ◽  
The Other ◽  
Al Alloy ◽  
Other Hand ◽  
Heat Treated ◽  
Ultrafine Grained ◽  
The Matrix ◽  
The Difference

In order to improve limited ductility of ultrafine grained (UFG) Al alloys, mechanical properties of an UFG Al alloy having fine precipitates within grains were investigated. An Al-0.2wt%Sc-4.2wt%Ag alloy was severely deformed by the ARB process at room temperature and subsequently heat-treated by a two-step aging. After the first aging in the two-step aging, fine Al3Sc precipitates were formed. In the specimen ARB processed by 4cycles, the fine Al3Sc precipitates were homogeneously dispersed within the grains. On the other hand, in the specimen ARB processed by 8 cycles, Al3Sc precipitates were linearly-aligned on the grain boundaries that had moved during the heat treatment. After the second aging, fine G.P. zones of Ag as well as Ag2Al precipitates were observed within the grains in the specimen ARB processed by 4 cycles. Coarse precipitates of Ag2Al at grain boundaries were observed in the specimen ARB processed by 8 cycles. The difference in the distribution of precipitates was considered to be due to the difference in fraction of high angle grain boundaries in the matrix microstructures. The strength of the solution treated specimen increased by the two-step aging while the tensile elongation decreased. On the other hand, both of the strength and elongation of the specimen ARB processed by 4 cycles increased after the two-step aging. In case of the specimen ARB processed by 8 cycles, the strength decreased slightly and the elongation increased by the two-step aging, and the aged specimen exhibited a good balance between strength and elongation.

Influences of the γ′ Phase on the Mechanical Properties of a Nickel-Based Single Crystal Superalloy

2021 ◽  
Vol 1023 ◽  
pp. 45-52
Author(s):  
Xiao Yan Wang ◽  
Meng Li ◽  
Zhi Xun Wen
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Single Crystal ◽  
Tensile Properties ◽  
Room Temperature ◽  
Solution Treatment ◽  
Single Crystal Superalloy ◽  
Original Material ◽  
Solid Solution Treatment ◽  
The Matrix

After solid solution treatment at 1335°C for 4 hours and cooling to room temperature at different rate, the nickel-based single crystal superalloy were made into three kinds of nickel-based single crystal superalloy materials containing different size γ′ phases, respectively. The tensile test of I-shaped specimens was carried out at 980°C, and their effect of γ′ phase microstructure on the tensile properties was studied. The results show that the yielding strength of the material air-cooled to room temperature was lower than that with cooling rate at 0.15°C/s, but both of them were lower than the yielding strength of original material. Little difference was found on the elastic modulus of I-shaped specimens made of three kinds of materials. When the cubic degree of the γ′ phase is higher and the size is larger, the tensile properties of the material is better, which can be attributed to the larger size and narrower channel of the matrix phase that lead to higher dislocation resistance.

scholarly journals Physical and Mechanical Properties Evaluation of Particle Board Produced from Saw Dust and Plastic Waste

2018 ◽  
Vol 40 ◽  
pp. 1-8 ◽  
Author(s):  
Atoyebi Olumoyewa Dotun ◽  
Adeolu Adesoji Adediran ◽  
Adisa Cephas Oluwatimilehin
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Weight Ratio ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Maximum Point ◽  
Mixing Ratios ◽  
Saw Dust ◽  
Three Phase ◽  
The Matrix

The current work reports on the fabrication of composite matrix from saw dust (SD) and recycled polyethylene terephthalate (PET) at different weight ratio by flat-pressed method. Wood plastic composites (WPCs) were made with a thickness of 15 mm after mixing the saw dust and PET followed by a three phase press cycle. Physical properties (Density, Water Absorption (WA) and Thickness Swelling (TS)) and Mechanical properties (Modulus of Elasticity (MOE) and Modulus of Rupture (MOR)) were determined base on the mixing ratios according to the standard. WA and TS were measured after 2 h and 24 h of immersion in water. The results showed that as the density increased, the SD content decreased from 90 % to 50 % into the matrix. However, WA and TS decreases when the PET content increased in the matrix. Remarkably, the MOE and MOR attained a maximum point at 964.199 N/mm2and 9.03 N/mm2respectively in 50 % SD content. In comparism with standard, boards D and E can be classified as medium density boards while A, B and C are low density boards. The results indicated that the fabrication of WPCs from sawdust and PET would technically be feasible for indoor uses in building due to favorable physical properties exhibited. The mechanical properties response showed that it cannot be used for structural or load bearing application.

scholarly journals The Effect of Reinforcement Ratio on the Composite Structure and Mechanical Properties in Al-MgO Composites Produced by the Melt Stirring Method

2011 ◽  
Vol 20 (4) ◽  
pp. 096369351102000 ◽  
Author(s):  
Recep Çalin ◽  
Pul Muharrem ◽  
Ramazan Çitak ◽  
Ulvi Şeker
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Metal Matrix ◽  
Vertical Direction ◽  
Homogeneous Distribution ◽  
Matrix Composites ◽  
Liquid Matrix ◽  
The Matrix ◽  
Micro Structures ◽  
Scanning Electron

In this study, Al- MgO metal matrix composites (MMC) were produced with 5 %, 10 % and 15 % reinforcement- volume (R-V) ratios by the melt stirring method. In the production of composites 99.5 % pure Al was used as the matrix and MgO powders with the particle size of −105 μm were used as the reinforcement. For every R-V ratio; stirring was made at 500 rev/min at 750°C liquid matrix temperature for 4 minutes and the samples were cooled under normal atmosphere. Then hardness and fracture strengths of the samples were determined and their micro structures were evaluated by using Scanning Electron Microscope (SEM). In general, it was observed that the reinforcement exhibited a homogeneous distribution in horizontal direction. But there is a slight inhomogeneity in vertical direction. It was determined that the increase in the R-V ratio increased the porosity and also the hardness. As for the fracture strength, the highest strength was obtained with the 5 % MgO reinforced sample.

Preparation and Mechanical Properties of Nano-SiCp/Mg Composites by Ultrasonic Dispersion

2010 ◽  
Vol 150-151 ◽  
pp. 792-795 ◽  
Author(s):  
Hong Yan ◽  
Zhi Hu
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Ultrasonic Method ◽  
Fracture Morphology ◽  
Dispersion Strengthening ◽  
Ultrasonic Dispersion ◽  
Sic Nanoparticles ◽  
The Matrix ◽  
Dislocation Strengthening ◽  
Magnesium Composites

SiC nanoparticles reinforced AZ61 magnesium composites were fabricated by Ultrasonic method. The distribution of nanoparticles in the matrix and the fracture morphology of the composites were observed by SEM, and the mechanical properties of the composites were tested at room temperature. Experimental shows that SiC nanoparticles were dispersed well in the matrix with the pretreatment method. Compared with the matrix, the tensile strength and hardness of the composites were improved respectively. Meanwhile, the ductility of the composites didn’t be obviously decreased. The enhancement function of nano composites was predicted with the dislocation strengthening and Orowan dispersion strengthening mechanisms. The predicted results coincided well with experimental ones.

A Study on Modification Properties of Silicone Rubber Using Organic Filler from Golden Apple Snail Shell

2016 ◽  
Vol 718 ◽  
pp. 40-44
Author(s):  
Sujirat Tepsila ◽  
Amnart Suksri
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Silicone Rubber ◽  
Room Temperature ◽  
Inorganic Filler ◽  
Apple Snail ◽  
Snail Shell ◽  
Hardness Property ◽  
Golden Apple Snail ◽  
Good Agreement

Silicone rubber room temperature vulcanization (RTV) is widely used as an insulator. This paper aims to improve the electrical and mechanical properties of RTV with organic filler from golden apple snail shells. The processed golden apple snail shells have the particle size of 75 μm. Specimen were made from silicone rubber with an addition of organic filler and inorganic filler for tested under ASTM D638-2a standard. The filler ratio was varying from 0 to 50% by weight with incremental of 5%. Experimental results showed that, there were good agreement in threshold of electrical and mechanical properties. RTV with the organic filler ratio of 40% out performed the inorganic filler in electrical aspect. Tensile strength of RTV was found to be increased when 5% addition of organic filler is used and decreases steadily as this filler is increased. The amount of filler has greater contribution to the hardness property of the RTV and it may become brittle when it is used in excessive amount.

scholarly journals Effect of Two-Stage Homogenization Heat Treatment on Microstructure and Mechanical Properties of AA2060 Alloy

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 40
Author(s):  
Chaoyang Chaoyang ◽  
Guangjie Guangjie ◽  
Lingfei Lingfei ◽  
Fei Fei ◽  
Lin Lin
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Cast Alloy ◽  
Hardness Test ◽  
Test Methods ◽  
Al Alloy ◽  
Two Stage ◽  
Homogenization Treatment ◽  
Transmission Electron ◽  
The Matrix

The microstructure evolution of AA2060 Al alloy containing Li during two-stage homogenization treatment was investigated by optical microscopy (OM), scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), differential scanning calorimeter (DSC), transmission electron microscopy (TEM), mechanical properties and Vickers micro-hardness test methods. The results demonstrate that severe precipitation of θ(Al2Cu) and S(Al2CuMg) phase existed in the as-cast alloy, especially in the center position. Cu elements were concentrated at grain boundary and gradually decreased from the boundary to the interior. Numerous eutectic phases of θ(Al2Cu) and S (Al2CuMg) containing Zn and Ag elements were segregated at grain boundaries. The overheating temperature of the as-cast alloy is 497 °C. After two-stage homogenization treatment, the θ(Al2Cu) and S (Al2CuMg) in the surface, middle and center positions were completely dissolved into the matrix, thus achieved uniform homogenization effect. Moreover, water cooling could prevent the precipitation after homogenization, which provided good performance of the studied alloy. The optimum two-stage homogenization treatment of AA2060 alloy was 460 °C/4 h + 490 °C/2 4 h. The homogenization kinetic analysis was discussed as well.

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