Microstructure and Mechanical Behaviour of Ultrafine Grained Al-4wt%Cu-(2.5-10) Vol.% SiC Metal Matrix Composites Produced by Powder Compact Forging

2011 ◽  
Vol 275 ◽  
pp. 208-213
Author(s):  
A. Gazawi ◽  
De Liang Zhang ◽  
K.L. Pickering ◽  
Aamir Mukhtar
Keyword(s):  
Metal Matrix ◽  
Powder Compact ◽  
Volume Fraction ◽  
High Energy ◽  
Matrix Composites ◽  
Plastic Yielding ◽  
Composite Powders ◽  
Ultrafine Grained ◽  
Powder Compacts ◽  
Small Plastic Strain

Ultrafine grained Al-4wt%Cu-(2.5-10) vol.% SiC metal matrix composite powders were produced from a mixture of Al, Cu and SiC powders using high energy mechanical milling (HEMM). The composite powders produced were first hot pressed at 300°C with a pressure of 240 MPa to produce cylindrical powder compacts with a relative density in the range of 80-94% which decreased with increasing the SiC volume fraction. Powder compact forging was utilized to consolidate the powder compacts into nearly fully dense forged disks. With increasing the volume fraction of SiC from 2.5% to 10%, the average microhardness of the forged disks increased from 73HV to 162HV. The fracture strength of the forged disks increased from 225 to 412 MPa with increasing the volume fraction of SiC particles from 2.5 to 10%. The Al-4wt%Cu-2.5vol.%SiC forged disk did not show any macroscopic plastic yielding, while the Al-4wt%Cu-(7.5 and 10)vol.% SiC forged disk showed macroscopic plastic yielding with a small plastic strain to fracture (~1%).

Mechanical Behaviour of Ultrafine Grained Cu and Cu-(2.5 and 5) Vol.%Al2O3 Composites Produced by Powder Compact Forging

2011 ◽  
Vol 275 ◽  
pp. 170-173
Author(s):  
Aamir Mukhtar ◽  
De Liang Zhang
Keyword(s):  
Composite Powder ◽  
Powder Compact ◽  
High Energy ◽  
High Yield ◽  
High Yield Strength ◽  
High Fracture ◽  
Composite Powders ◽  
Al2o3 Composite ◽  
Ultrafine Grained ◽  
Powder Compacts

Nanostructured Cu-(2.5 and 5)vol.%Al2O3 composite powders were produced from a mixture of Cu powder and Al2O3 nanopowder using high energy mechanical milling, and then compacted by hot pressing. The Cu and Cu-Al2O3 composite powder compacts were then forged into disks at temperatures in the range of 500-800°C to consolidate the Cu and Cu-Al2O3 composite powders. Tensile testing of the specimens cut from the forged disks showed that the Cu forged disk had a good ductility (plastic strain to fracture: ~15%) and high yield strength of 320 MPa, and the Cu-(2.5 and 5)vol.%Al2O3 composite forged disks had a high fracture strength in range of 530-600 MPa, but low ductility.

MICROSTRUCTURES AND MECHANICAL PROPERTIES OF ULTRAFINE GRAINED Ti-47Al-2Cr (at %) ALLOY PRODUCED USING POWDER COMPACT FORGING

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1739-1744
Author(s):  
VIJAY N. NADAKUDURU ◽  
DELIANG ZHANG ◽  
PENG CAO ◽  
BRIAN GABBITTAS
Keyword(s):  
Mechanical Properties ◽  
Powder Compact ◽  
High Energy ◽  
Alloy Sample ◽  
Bulk Alloy ◽  
Porosity Level ◽  
Fine Grain ◽  
Ultrafine Grained ◽  
Powder Compacts ◽  
Innovative Techniques

Development of innovative techniques to produce gamma TiAl based alloys, with good mechanical properties, while still maintaining ultra fine grain size can be rewarding, but also is a great challenge. In the present study study a Ti -47 Al -2 Cr ( at %) alloy has been synthesized by directly forging green powder compacts of a Ti / Al / Cr composite powder produced by high energy mechanical milling of a mixture of elemental Ti , Al , Cr powders. It has been found that the density of the bulk consolidated alloy sample after forging decreases from 95% of the theoretical density in the central region to 84% in the periphery region. The microstructure of the bulk alloy consisted of several Ti rich regions, which was expected to be mainly due to initial powder condition. The room temperature tensile strength of the samples produced from this process was found to be in the range of 115 – 130 MPa. The roles of canning and green powder compact density in determining the forged sample porosity level and distribution are discussed.

scholarly journals Predictive Computational Model for Damage Behavior of Metal-Matrix Composites Emphasizing the Effect of Particle Size and Volume Fraction

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2143
Author(s):  
Shaimaa I. Gad ◽  
Mohamed A. Attia ◽  
Mohamed A. Hassan ◽  
Ahmed G. El-Shafei
Keyword(s):  
Finite Element ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Particulate Composites ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Zone Method ◽  
Stress Strain ◽  
The Matrix

In this paper, an integrated numerical model is proposed to investigate the effects of particulate size and volume fraction on the deformation, damage, and failure behaviors of particulate-reinforced metal matrix composites (PRMMCs). In the framework of a random microstructure-based finite element modelling, the plastic deformation and ductile cracking of the matrix are, respectively, modelled using Johnson–Cook constitutive relation and Johnson–Cook ductile fracture model. The matrix-particle interface decohesion is simulated by employing the surface-based-cohesive zone method, while the particulate fracture is manipulated by the elastic–brittle cracking model, in which the damage evolution criterion depends on the fracture energy cracking criterion. A 2D nonlinear finite element model was developed using ABAQUS/Explicit commercial program for modelling and analyzing damage mechanisms of silicon carbide reinforced aluminum matrix composites. The predicted results have shown a good agreement with the experimental data in the forms of true stress–strain curves and failure shape. Unlike the existing models, the influence of the volume fraction and size of SiC particles on the deformation, damage mechanism, failure consequences, and stress–strain curve of A359/SiC particulate composites is investigated accounting for the different possible modes of failure simultaneously.

Thermomechanical Behavior of Low CTE Metal-Matrix Composites Fabricated Through Ultrasonic Additive Manufacturing

2012 ◽  
Author(s):  
Ryan Hahnlen ◽  
Marcelo J. Dapino
Keyword(s):  
Shear Strength ◽  
Additive Manufacturing ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Large Strain ◽  
Matrix Composites ◽  
Interface Shear ◽  
Mechanical Coupling ◽  
Ultrasonic Additive Manufacturing

Shape memory and superelastic NiTi are often utilized for their large strain recovery and actuation properties. The objective of this research is to utilize the stresses generated by pre-strained NiTi as it is heated in order to tailor the CTE of metal-matrix composites. The composites studied consist of an Al 3003-H18 matrix with embedded NiTi ribbons fabricated through an emerging rapid prototyping process called Ultrasonic Additive Manufacturing (UAM). The thermally-induced strain of the composites is characterized and results show that the two key parameters in adjusting the effective CTE are the NiTi volume fraction and prestrain of the embedded NiTi. From the observed behavior, a constitutive composite model is developed based constitutive SMA models and strain matching composite models. Additional composites were fabricated to characterize the NiTi-Al interface through EDS and DSC. These methods were used to investigate the possibility of metallurgical bonding between the ribbon and matrix and determine interface shear strength. Interface investigation indicates that mechanical coupling is accomplished primarily through friction and the shear strength of the interface is 7.28 MPa. Finally, using the developed model, a composite was designed and fabricated to achieve a near zero CTE. The model suggests that the finished composite will have a zero CTE at a temperature of 135°C.

scholarly journals Extraction of void fraction in metal matrix composite using morphological image processing

1994 ◽  
Vol 3 (2) ◽  
pp. 096369359400300
Author(s):  
Lun X. He ◽  
David K. Hsu ◽  
John P. Basart
Keyword(s):  
Image Processing ◽  
Void Fraction ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Matrix Material ◽  
Void Content ◽  
Matrix Composites ◽  
Cross Sectional ◽  
Morphological Image Processing ◽  
The Matrix

In continuous fiber reinforced metal matrix composites, the volume fraction of voids in the matrix material is an important parameter for material property characterization. In analyzing a cross-sectional micrograph of such a composite, the presence of fiber images and voids occurring on the perimeter of fibers complicates the determination of void content. This paper describes image processing steps using mathematical morphology for the extraction of void fraction in a composite.

Novel Ultrafine-Grained Aluminium Metal Matrix Composites Prepared from Fine Atomized Al Powders

2014 ◽  
pp. 1425-1430
Author(s):  
M. Balog ◽  
F. Simancik ◽  
P. Krizik ◽  
M. Nosko ◽  
W. Rajner ◽  
...  
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Matrix Composites ◽  
Ultrafine Grained ◽  
Aluminium Metal

Constrained network model for predicting densification behavior of composite powders

1987 ◽  
Vol 2 (1) ◽  
pp. 59-65 ◽  
Author(s):  
F. F. Lange
Keyword(s):  
Network Model ◽  
Powder Compact ◽  
Volume Fraction ◽  
Random Network ◽  
Simple Relation ◽  
Unit Cell ◽  
Densification Behavior ◽  
Inert Particle ◽  
Composite Powders ◽  
Inert Particles

Inert particles that do not contribute to the densification of a composite powder compact are visualized as located on network sites; the network is defined by the distribution of the particles in the powder matrix. Because the distances between neighboring network sites are not identical, the strain produced by the sintering powder between all inert particle pairs cannot be the same as that for the powder compact without the inert particles. The constrained network model is based on the hypothesis that the densification of the composite will be constrained by the network and will mimic that of the network. The shrinkage of the network, and thus the densification of the composite, is estimated with a periodic network. A distance between the minimum and maximum site pairs within the unit cell defines the distance between site pairs in the random network where the powder between the particles densifies in the same manner as that for the powder without the inert particle. When the particles form a continuous touching network, composite shrinkage and densification is nil. The chosen lattice must also conform to this condition. A simple relation was developed relating the densification behavior of the composite to that of the matrix without the inert particles and the parameter associated with the chosen lattice. By choosing the lattice formed by the tetrakaidecahedron unit cell (volume fraction of particles for a touching network = 0.277), remarkable agreement was achieved for the experimental data concerning the densification behavior of the ZnO/SiC composite system reported by De Jonghe et al. [L. C. De Jonghe, M. N. Rahaman, and C. H. Hsueh, Acta Metall. 34, 1467 (1986)]. The universal nature of this lattice for other composites is discussed with respect to site percolation theory. The application of this concept to powder compacts containing either whiskers or agglomerates is briefly discussed.

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