Orientation Studies of α-Al(Fe,Mn)Si Dispersoids in 3xxx Al Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 39-44 ◽  
Author(s):  
Astrid Marie Flattum Muggerud ◽  
Yan Jun Li ◽  
Randi Holmestad
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Orientation Relationship ◽  
Aluminum Matrix ◽  
Al Alloys ◽  
Orientation Relationships ◽  
The Matrix ◽  
The Common ◽  
Habit Planes ◽  
Al Matrix

Dispersoids are important in 3xxx Al alloys, influencing mechanical properties, texture and recrystallization. In this work α-Al (Fe,Mn)Si dispersoids have been studied after low temperature homogenisation. The common orientation relationship between dispersoids and Al matrix has been reported in earlier studies. Here a systematic study on the orientation relationship and its exceptions is presented. It is found that most of the dispersoids follow the common orientation relationship, [1-1 1] α //[1-1 1]Al , (5-2 -7 ) α //(0 1 1)Al . Here the dispersoids are semi coherent with the Aluminum matrix. Different morphologies and habit planes are possible. Deviations from the most commonly observed orientation relationships are presented and discussed, to underline the complexity of the phase and its relation to the matrix.

On the multiple orientation relationship of the Mg/γ-Mg17Al12precipitation system

2012 ◽  
Vol 45 (2) ◽  
pp. 224-233 ◽  
Author(s):  
Hongwei Liu ◽  
Jiangwen Liu ◽  
Liuzhang Ouyang ◽  
Chengping Luo
Keyword(s):  
Orientation Relationship ◽  
Simple Structure ◽  
Close Packing ◽  
Orientation Relationships ◽  
Complicated Structure ◽  
Starting Point ◽  
The Matrix ◽  
Gross Energy ◽  
Relationship Of ◽  
Habit Planes

The six orientation relationships (ORs) found in the Mg/γ-Mg17Al12precipitation system were summarized and systematically interpreted based on the atomic structure of the precipitate γ-Mg12Al17and the invariant deformation element (IDE) model for diffusional phase transformations. It was found that the pseudo-twinning relationship between the six ORs is a reflection of the pseudo-twinning relationship between the close- or near-close-packing planes ({\overline 8}\hskip.75{\overline 7}\hskip.75{\overline 7}), ({\overline 4}11), (033), (411) and (8{\overline 7}\hskip.75{\overline 7}) in the precipitate γ-Mg12Al17. As a result, the Pitsch–Schrader OR is the starting point for the other five ORs. Multiple morphologies, growth directions and habit planes could be rationally interpreted by the IDE model. This implies that a multiple orientation relationship between the variants of precipitates is favourable in order to minimize the gross energy of precipitation systems in which the matrix has a simple structure while the precipitate has a complicated structure, such as Mg/γ-Mg12Al17, Mg/δ-Zn2Zr3and Mg/η-MgZn2couples.

The orientation relationships of nanobelt-like Si2Hf precipitates in an Al–Si–Mg–Hf alloy

2016 ◽  
Vol 49 (4) ◽  
pp. 1223-1230 ◽  
Author(s):  
Xueli Wang ◽  
Huilan Huang ◽  
Xinfu Gu ◽  
Yanjun Li ◽  
Zhihong Jia ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Coincident Site Lattice ◽  
Orthorhombic Structure ◽  
Orientation Relationships ◽  
Lattice Distribution ◽  
Site Lattice ◽  
Transmission Electron ◽  
Habit Planes ◽  
Al Matrix

The orientation relationships (ORs) between the Al matrix and Si2Hf precipitates with an orthorhombic structure in an Al–Si–Mg–Hf alloy after heat treatment at 833 K for 20 h were investigated by transmission electron microscopy and electron diffraction. Four ORs are identified as (100)Al||(010)p, (0\overline {1}1)Al||(101)pand [011]Al||[\overline {1}01]p; (11\overline {1})Al||(010)pand [011]Al||[\overline {1}01]p; (12\overline {1})Al||(010)p, (101)Al||(100)pand [1\overline {11}]Al||[001]p; (\overline {11}1)Al||(010)pand [112]Al||[\overline {1}01]p. The habit planes of these four ORs are rationalized by the fraction of good atomic matching sites at the interface. In addition, the formation of Si2Hf precipitates with a nanobelt-like morphology is interpreted on the basis of the near-coincident site lattice distribution.

scholarly journals Structural and Mechanical Properties of Amorphous Si3N4 Nanoparticles Reinforced Al Matrix Composites Prepared by Microwave Sintering

Ceramics ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 126-134 ◽  
Author(s):  
Manohar Mattli ◽  
Penchal Matli ◽  
Abdul Shakoor ◽  
Adel Amer Mohamed
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Yield Strength ◽  
Volume Fraction ◽  
Microwave Sintering ◽  
Aluminum Matrix ◽  
Microstructural Investigation ◽  
Porosity Level ◽  
Amorphous Si3n4 ◽  
Al Matrix

The present study focuses on the synthesis and characterization of amorphous silicon nitride (Si3N4) reinforced aluminum matrix nanocomposites through the microwave sintering process. The effect of Si3N4 (0, 1, 2 and 3 wt.%) nanoparticles addition to the microstructure and mechanical properties of the Al-Si3N4 nanocomposites were investigated. The density of Al-Si3N4 nanocomposites increased with increased Si3N4 content, while porosity decreased. X-ray diffraction (XRD) analysis reveals the presence of Si3N4 nanoparticles in Al matrix. Microstructural investigation of the nanocomposites shows the uniform distribution of Si3N4 nanoparticles in the aluminum matrix. Mechanical properties of the composites were found to increase with an increasing volume fraction of amorphous Si3N4 reinforcement particles. Al-Si3N4 nanocomposites exhibits higher hardness, yield strength and enhanced compressive performance than the pure Al matrix. A maximum increase of approximately 72% and 37% in ultimate compressive strength and 0.2% yield strength are achieved. Among the synthesized nanocomposites, Al-3wt.% Si3N4 nanocomposites displayed the maximum hardness (77 ± 2 Hv) and compressive strength (364 ± 2 MPa) with minimum porosity level of 1.1%.

scholarly journals Effect of Increasing the Strength of Aluminum Matrix Nanocomposites Reinforced with Microadditions of Multiwalled Carbon Nanotubes Coated with TiC Nanoparticles

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1596 ◽  
Author(s):  
Artemiy Aborkin ◽  
Kirill Khorkov ◽  
Evgeny Prusov ◽  
Anatoly Ob’edkov ◽  
Kirill Kremlev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Aluminum Matrix ◽  
High Energy ◽  
High Tech ◽  
Multiwalled Carbon ◽  
The Matrix ◽  
Tic Nanoparticles ◽  
Matrix Nanocomposites

Aluminum matrix composites reinforced with multiwalled carbon nanotubes (MWCNTs) are promising materials for applications in various high-tech industries. Control over the processes of interfacial interaction in Al/MWCNT composites is important to achieve a high level of mechanical properties. The present study describes the effects of coating MWCNTs with titanium carbide nanoparticles on the formation of mechanical properties and the evolution of the reinforcement structure in bulk aluminum matrix nanocomposites with low concentrations of MWCNTs under conditions of solid-phase consolidation of ball-milled powder mixtures. Using high-energy ball milling and uniaxial hot pressing, two types of bulk nanocomposites based on aluminum alloy AA5049 that were reinforced with microadditions of MWCNTs and MWCNTs coated with TiC nanoparticles were successfully produced. The microstructural and mechanical properties of the Al/MWCNT composites were investigated. The results showed that, on the one hand, the TiC nanoparticles on the surface of the MWCNT hybrid reinforcement reduced the damage of reinforcement under the intense exposure of milling bodies, and on the other hand, they reduced the contact area of the MWCNTs with the matrix material (acting as a barrier interface), which also locally inhibited the reaction between the matrix and the MWCNTs.

Microstructures and Mechanical Properties of 6061 Al Matrix Smart Composite Containing TiNi Shape Memory Fiber

1996 ◽  
Vol 459 ◽  
Author(s):  
J. H. Lee ◽  
K. Hamada ◽  
K. Miziuuchia ◽  
M. Taya ◽  
K. Inoue
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Elevated Temperatures ◽  
Volume Fraction ◽  
Matrix Material ◽  
Matrix Alloy ◽  
Flow Strength ◽  
The Matrix ◽  
Shape Memory Fiber ◽  
Al Matrix

ABSTRACT6061 Al-matrix composite with TiNi shape memory fiber as reinforcement has been fabricated by vacuum hot pressing to investigate the microstructure and mechanical properties. The yield stress of this composite increases with increasing amount of prestrain, and it also depends on the volume fraction of fiber and heat treatment. The smartness of the composite is given due to the shape memory effect of the TiNi fiber which generates compressive residual stresses in the matrix material when heated after being prestrained. Microstructual observations have revealed that interfacial reactions occur between the matrix and fiber, creating two intermetallic layers. The flow strength of the composite at elevated temperatures is significantly higher than that of the matrix alloy without TiNi fiber.

scholarly journals Titanium Dioxide Coated Graphene Nanosheets as a Reinforcement in Aluminum Matrix Composites Based on Pressure Sintering Process

2020 ◽  
Author(s):  
Zheng-Hua Guo ◽  
Qingjie Wu ◽  
Ning Li ◽  
Li-Hong Jiang ◽  
Wen He ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Dioxide ◽  
Load Transfer ◽  
Graphene Nanosheets ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Powder Metallurgy Method ◽  
Matrix Composites ◽  
The Matrix ◽  
Coating Layers

Abstract Graphene nanoplatelets (GNPs) reinforced 7075 aluminum (Al) nanocomposites were successfully synthesized using the powder metallurgy method. A novel method for optimizing interfacial bonding by coating titanium dioxide (TiO 2 ) on the surface of GNPs was proposed in this manuscript. The effects of GNPs on mechanical properties and microstructure of the aluminum matrix nanocomposites, both with and without TiO 2 coating layers, have been investigated. Experimental results showed that the corresponding mechanical properties of the nanocomposites were further improved when the GNPs have TiO 2 coating layers, compared with the addition of pure GNPs. The yield strength, ultimate tensile strength, and microhardness of the nanocomposites reinforced with TiO 2 -coated GNPs increased by 22.9%, 25.9%, and 20.1%, respectively, in comparison to those of the matrix. The further improvement of the mechanical properties could be attributed to the existence of the coating layer, which optimizes the interface bonding between the reinforcement and the matrix, thereby improving the effectiveness of load transfer.

scholarly journals Study of Microstructural and Mechanical Properties of Al/SiC/TiO2 Hybrid Nanocomposites Developed by Microwave Sintering

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1078
Author(s):  
Manohar Reddy Mattli ◽  
Penchal Reddy Matli ◽  
Adnan Khan ◽  
Rokaya Hamdy Abdelatty ◽  
Moinuddin Yusuf ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tio2 Nanoparticles ◽  
Microwave Sintering ◽  
Aluminum Matrix ◽  
Hybrid Nanocomposites ◽  
Shear Mode ◽  
Fixed Amount ◽  
Metal Matrix Nanocomposites ◽  
Hybrid Metal Matrix Nanocomposites ◽  
Al Matrix

Aluminum hybrid metal matrix nanocomposites (Al/SiC/TiO2) were synthesized through a microwave-assisted powder metallurgy process, and their evolved microstructure and mechanical properties were investigated. The Al/SiC/TiO2 hybrid nanocomposites were prepared by reinforcing aluminum (Al) matrix with a fixed amount of silicon carbide (SiC) nanoparticles (5 wt.%) and varying concentrations of titanium dioxide (TiO2) nanoparticles (3, 6, and 9 wt.%). The morphology results revealeda uniform distribution of SiC and TiO2 reinforcements in the aluminum matrix. An increase in the hardness and compressive strength of the Al/SiC/TiO2 hybrid nanocomposites was noticed with the increasein TiO2 nanoparticles. The Al/SiC/TiO2 hybrid nanocomposites that had an optimum amount of TiO2 nanoparticles (9 wt.%) showcased the best mechanical properties, with maximum increments of approximately 124%, 90%, and 23% of microhardness (83 ± 3 HV), respectively, yield strength (139 ± 8 MPa), and ultimate compression strength (375 ± 6 MPa) as compared to that of pure Al matrix. The Al/SiC/TiO2 hybrid nanocomposites exhibited the shear mode of fracture during their deformation process.

Preparation and Characterization of Hybrid Aluminum Matrix Composites Reinforced with MWCNT Using Powder Metallurgy Process

2015 ◽  
Vol 813-814 ◽  
pp. 620-624
Author(s):  
S. Dhandapani ◽  
T. Rajmohan ◽  
K. Palanikumar ◽  
Charan Mugunthan
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Metal Matrix ◽  
Matrix Material ◽  
Aluminum Matrix ◽  
Nano Particles ◽  
Aluminum Matrix Composites ◽  
The Matrix ◽  
Carbon Nano Tubes

Metal Matrix Nano Composites (MMNC) consist of a metal matrix reinforced with nano-particles featuring physical and mechanical properties very different from those of the matrix. Especially carbon Nano tubes (CNT) can improve the matrix material in terms of wear resistance, damping properties and mechanical strength. The present investigation deals with the synthesis and characterization of aluminium matrix reinforced with micro B4C particles, and Multi Wall Carbon nano Tubes (MWCNT) were prepared by powder metallurgy route. Powder mixture containing fixed weight (%) of B4C and different wt% of MWCNT as reinforcement constituents that are uniaxial cold pressed and later green compacts are sintered in continues electric furnace. Microstructure and Mechanical properties such as micro hardness and density are examined. Micro structure of samples has been investigated using scanning electron microscope (SEM) .The results indicated that the increase in wt % of MWCNT improves the bonding and mechanical properties.

A symmetry-violating precipitation process induced under irradiation

1990 ◽  
Vol 48 (4) ◽  
pp. 930-931
Author(s):  
W. Kesternich
Keyword(s):  
Orientation Relationship ◽  
Neutron Irradiation ◽  
Dark Field ◽  
Fast Neutrons ◽  
Double Diffraction ◽  
Cube Orientation ◽  
Precipitate Growth ◽  
The Matrix ◽  
The Common ◽  
Diffraction Effects

TiC precipitates in austenitic steel have been found to reveal a very unusual precipitation behaviour /l,2/. As a consequence, nucleation initiated by dislocation recovery or growth induced during recrystallization can be used to create predesired modifications of the microstructure and the mechanical properties /2—3/. The extraordinary high resistance to precipitate growth and coarsening /l/ appears to be the key property in these applications and also appears to be the origin for a unique precipitate phenomenon which was observed in the present irradiation experiment.A 1.4970 type steel (15Ni—15Cr austenite, containing Ti and C) was neutron irradiated at 845 K to a dose of 2.6 x 1025 m-2 thermal neutrons (helium production) and 3.0 x 1025 fast neutrons (1.5dpa). Before irradiation the steel was solution annealed leaving about half of the Ti and C in supersaturated solution. Defect cascades introduced by the neutron irradiation acted as nucleation centres for MC (M=Ti, Nb, Mo...) precipitates as has already previously been demonstrated in Ti- and Nb-stabilized steels /4/. In addition to the common, irregularly shaped MC precipitates, however, two further precipitate variants were created during the present high temperature neutron irradiation. One precipitate variant was star—shaped with cube—on—cube orientation relationship with the matrix. The other variant was nail—shaped. Analysis of crystal structure and orientation relationship of the nail—shaped precipitates was made difficult by their small shape and by double diffraction effects. Fig. la shows a (001) SAD pattern of matrix (heavy spots) and precipitates (fine spots). The quadruplets in the vicinity of <110> are created from the new precipitates. Each of the four quadruplet spots actually consists of three closely spaced spots (Fig. lb), and the eight precipitate spots surrounding each of the matrix spots in Fig. la each consist of two spots. After the double diffraction effects had been assigned (schematic in Fig. lb for example) they were reduced by specified specimen tilting around two axes (Fig. lc). It was found by combined dark- field and diffraction analyses that all diffraction spots originated from TiC precipitates and that four orientation variants of the TiC precipitates were distinguishable. They are imaged in Fig. 1d in bright field and in Fig. 2 in four corresponding dark field images by using reflections 0 to 3 of Fig. lc. 0 shows precipitates of the common cube—on— cube orientation relationship. 1 to 3 shows nail—shaped precipitates with nail axes pointing along the three <110> directions. The diffraction analysis revealed that the lattice of the nail precipitates is rotated by 45 degrees around the nail axes from cube-on-cube orientation, thus giving rise to the three orientation variants.

Synthesis and Mechanical Properties of a Novel Al/Β-Al3Mg2 Nanocomposite Prepared by Mechanical Alloying Process

2012 ◽  
Vol 445 ◽  
pp. 827-832 ◽  
Author(s):  
R.A. Khosroshahi ◽  
A. Zolriasatein ◽  
M. Emamy ◽  
N. Nemati
Keyword(s):  
Mechanical Properties ◽  
Materials Science ◽  
Aluminum Matrix ◽  
Microstructural Characterization ◽  
Optical Microscope ◽  
Composite Powders ◽  
New Class ◽  
The Matrix ◽  
Complex Metallic Alloys ◽  
Wear Tests

Complex metallic alloys (CMA) are new crystalline intermetallic phases representing an upcoming field in materials science. The β-Al3Mg2 intermetallic compound belongs to this new class of materials. Different amounts of pre-alloyed β-Al3Mg2 nanoparticles (from 0 to 20 wt.%) were mixed with aluminum matrix powder and then co-milled in attrition ball mill for 10 hours. Consolidated samples were prepared by hot pressing of blended composite powders. Microstructural characterization, applying an optical microscope (OM) and scanning electron microscope (SEM) equipped with an energy dispersive X-ray (EDX) analyzer confirmed the formation of uniformly distributed β-Al3Mg2 nanoparticles in the matrix. Furthermore the results indicated that, increasing the amounts of β-Al3Mg2 nanoparticles leads the matrix grain size to be reduced. Effects of reinforcement contents on mechanical properties of nanocomposite samples were also investigated via hardness, compressive and wear tests. The results revealed that with increasing reinforcement content in the matrix, mentioned attributes of the composites are significantly improved.

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