scholarly journals Hypereutectic Al-Ca-Mn-(Ni) Alloys as Natural Eutectic Composites

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 890
Author(s):  
Evgeniya Naumova ◽  
Vitali Doroshenko ◽  
Mikhail Barykin ◽  
Tatyana Sviridova ◽  
Alexandra Lyasnikova ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Phase Distribution ◽  
Solid Phase ◽  
Coefficient Of Thermal Expansion ◽  
Matrix Composites ◽  
Ni Alloys ◽  
System A ◽  
Thermo Calc Software ◽  
As Stress ◽  
Stress Raisers

In the present paper, Natural Metal-Matrix Composites (NMMC) based on multicomponent hypereutectic Al-Ca-(Mn)-(Ni) alloys were studied in as-cast, annealed and rolled conditions. Thermo-Calc software and microstructural observations were utilised for analysing the equilibrium and actual phase composition of the alloys including correction of the Al-Ca-Mn system liquidus projection and the solid phase distribution in the Al-Ca-Mn-Ni system. A previously unknown Al10CaMn2 was discovered by both electron microprobe analysis and X-ray studies. The Al-6Ca-3Mn, Al-8Ca-2Mn, Al-8Ca-2Mn-1Ni alloys with representative NMMC structure included ultrafine Сa-rich eutectic and various small-sized primary crystals were found to have excellent feasibility of rolling as compared to its hypereutectic Al-Si counterpart. What is more, Al-Ca alloys showed comparable Coefficient of Thermal Expansion values due to enormous volume fraction of Al-based eutectic and primary intermetallics. Analysis of tensile samples’ fracture surfaces revealed that primary intermetallics may act either as stress raisers or malleable particles depending on their stiffness under deformation. It is shown that a compact morphology can be achieved by conventional casting without using any refining agents. Novel hypereutectic Al-Ca NMMC materials solidifying with the formation of Al10Mn2Ca primary compound have the best ductility and strength. We reasonably propose these materials for high-load pistons.

Fabrication by SPS and Thermophysical Properties of High Volume Fraction SiCp/Al Matrix Composites

2006 ◽  
Vol 313 ◽  
pp. 171-176 ◽  
Author(s):  
X.F. Gu ◽  
Lian Meng Zhang ◽  
Mei Jun Yang ◽  
Dong Ming Zhang
Keyword(s):  
Thermophysical Properties ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
High Volume ◽  
High Volume Fraction ◽  
Matrix Composites ◽  
Sic Particles ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Al Matrix Composites

SiCp/Al composites containing high volume fraction of SiC particles were fabricated by spark plasma sintering (SPS), and their thermophysical properties, such as thermal conductivity (TC) and coefficient of thermal expansion (CTE), were characterized. High relative density (R-D) of composites was successfully achieved through the optimization of sintering parameters, such as sintering temperature, sintering pressure and heating rate. The measured TCs of SiCp/Al composites fabricated by SPS are higher than 195W/m.k, no matter the volume fraction of SiC particles is high or low as long as the R-D is higher than 95%. The measured CTEs of SiCp/Al composites are in good agreement with the estimated values based on Kerner,s model. The high volume fraction of SiCp/Al composites are a good candidate material to substitute for conventional thermal management materials in advanced electronic packages due to its tailorable thermophysical properties.

Diamond-Based Metal Matrix Composites for Thermal Management Made by Liquid Metal Infiltration — Potential and Limits

2008 ◽  
Vol 59 ◽  
pp. 111-115 ◽  
Author(s):  
Ludger Weber ◽  
Reza Tavangar
Keyword(s):  
Thermal Conductivity ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Room Temperature ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Diamond Powder ◽  
Matrix Composites ◽  
Pressure Infiltration ◽  
The One

Diamond-based metal matrix composites have been made based on pure Al and eutectic Ag-3Si alloy by gas pressure infiltration into diamond powder beds with the aim to maximize thermal conductivity and to explore the range of coefficient of thermal expansion (CTE) that can be covered. The resulting composites covered roughly the range between 60 and 75 vol-% of diamond content. For the Al-based composites a maximum thermal conductivity at room temperature of 7.6 W/cmK is found while for the Ag-3Si based composites an unprecedented value of 9.7 W/cmK was achieved. The CTE at room temperature varied as a function of the diamond volume fraction between 3.3 and 7.0 ppm/K and 3.1 and 5.7 ppm/K for the Al-based and the Ag-3Si-based composites, respectively. The CTE was further found to vary quite significantly with temperature for the Al-based composites while the variation with temperature was less pronounced for the Ag-3Si-based composites. The results are compared with prediction by analytical modeling using the differential effective medium scheme for thermal conductivity and the Schapery bounds for the CTE. For the thermal conductivity good agreement is found while for the CTE a transition of the experimental data from Schapery’s upper to Schapery’s lower bound is observed as volume fraction increases. While the thermophysical properties are quite satisfactory, there is a trade-off to be made in these materials between high thermal conductivity and low CTE on the one side and surface quality and machinability on the other.

AlN nanowires for Al-based composites with high strength and low thermal expansion

2007 ◽  
Vol 22 (10) ◽  
pp. 2711-2718 ◽  
Author(s):  
Y.B. Tang ◽  
Y.Q. Liu ◽  
C.H. Sun ◽  
H.T. Cong
Keyword(s):  
Thermal Expansion ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Maximum Yield ◽  
High Strength ◽  
Mechanical And Thermal Properties ◽  
Matrix Composites ◽  
Interfacial Reaction Product ◽  
Low Thermal Expansion ◽  
Al Matrix

Based on the synthesis of a sufficient amount of AlN nanowires (AlN-NWs), AlN-NWs/Al composites with homogenously distributed AlN-NWs were fabricated. Microstructural observations reveal that the interface between AlN-NWs and Al matrix is clean and bonded well, and no interfacial reaction product was formed at the nanowire-matrix boundary. Mechanical properties including yield and tensile strength of the composites were improved with AlN-NWs volume fraction changing from 5 to 15 vol%, and the maximum yield and tensile strengths of the composite were about 6 and 5 times, respectively, as high as those of Al matrix. Meanwhile, AlN-NWs effectively decreased the coefficient of thermal expansion (CTE) of the composites, and the CTE of 15 vol% composite was about one half that of Al matrix. The results obtained suggest that AlN nanowire is a promising reinforcement for optimizing the mechanical and thermal properties of metal matrix composites.

Structural and Thermal Properties of Hot Pressed Cu/C Matrix Composites Materials Used for the Thermal Management of High Power Electronic Devices

2007 ◽  
Vol 534-536 ◽  
pp. 1505-1508 ◽  
Author(s):  
Pierre Marie Geffroy ◽  
Jean François Silvain
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Carbon Fibers ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Copper Matrix ◽  
Matrix Composites ◽  
Porosity Level ◽  
Materials Used ◽  
Short Carbon

In order to obtain materials for electronic applications that exhibit both excellent thermal conductivity and low coefficient of thermal expansion (CTE), copper matrix composites have been reinforced by short high modulus graphite fibers. The lack of fiber/matrix interaction prevents any degradation of the carbon reinforcement during the elaboration steps and the normal use of these materials. Elaboration conditions, such as mixing conditions of the short carbon fibers and the copper powder, dimension and shape of the two powders, and finally densification atmosphere, temperature, pressure and time, have been optimized. Main parameters involved in the thermal properties of the Cu/C composite materials have been analyzed and adjusted. CTE is mainly related with the carbon volume fraction; CTE ranging from 9 to 13 10-6/°C can be reproductively obtained with carbon volume fraction ranging from 50% to 20%. Thermal conductivity properties are more complex and are linked mainly with 1) the porosity level inside the material, and 2) the orientation, properties and volume fraction of the carbon fibers. For short carbon fibers, in plane thermal conductivity ranging from 200 to 550 W/mK have been reproductively measured associated with thermal conductivity through-thickness ranging from 150 to 300 W/mK.

The behaviour of aluminium matrix composites under thermal stresses

2016 ◽  
Vol 23 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Khushbu Dash ◽  
Suvin Sukumaran ◽  
Bankim C. Ray
Keyword(s):  
Thermal Conductivity ◽  
Thermal Cycling ◽  
Thermal Fatigue ◽  
Thermal Stresses ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Interparticle Spacing ◽  
Aluminium Matrix ◽  
Matrix Composites ◽  
Aluminium Matrix Composites

AbstractThe present review work elaborates the behaviour of aluminium matrix composites (AMCs) under various kinds of thermal stresses. AMCs find a number of applications such as automobile brake systems, cryostats, microprocessor lids, space structures, rocket turbine housing, and fan exit guide vanes in gas turbine engines. These applications require operation at varying temperature conditions ranging from high to cryogenic temperatures. The main objective of this paper was to understand the behaviour of AMCs during thermal cycling, under induced thermal stresses and thermal fatigue. It also focuses on the various thermal properties of AMCs such as thermal conductivity and coefficient of thermal expansion (CTE). CTE mismatch between the reinforcement phase and the aluminium matrix results in the generation of residual thermal stress by virtue of fabrication. These thermal stresses increase with increasing volume fraction of the reinforcement and decrease with increasing interparticle spacing. Thermal cycling enhances plasticity at the interface, resulting in deformation at stresses much lower than their yield stress. Low and stable CTE can be achieved by increasing the volume fraction of the reinforcement. The thermal fatigue resistance of AMC can be increased by increasing the reinforcement volume fraction and decreasing the particle size. The thermal conductivity of AMCs decreases with increase in reinforcement volume fraction and porosity.

Analysis of Coefficient of Thermal Expansion and Thermal Conductivity of Bi-Modal SiC/A356 Composites Fabricated via Powder Metallurgy Route

2017 ◽  
Author(s):  
Preetkanwal Singh Bains ◽  
H. S. Payal ◽  
Sarabjeet Singh Sidhu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Powder Metallurgy ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Powder Metallurgy Method ◽  
Matrix Composites ◽  
Sic Particulates

The present study investigates the thermal conductivity and coefficient of thermal expansion of bimodal SiCp reinforced Aluminum matrix composites formed via powder metallurgy method. The after-effects of proportion of particulate reinforcement as size distribution and sintering parameters on the thermal properties have been explored. The Box-Behnken design for response surface methodology was adopted to recognize the significance of chosen variables on the thermal conductivity and coefficient of thermal expansion of the composite. It is witnessed that the thermal conductivity and coefficient of thermal expansion enhanced due to increase in fine SiC particulates volume fraction. It has been exhibited that the fine SiC particulates (37μm) doped Al-matrix occupied interstitial positions and developed continuous SiC-matrix network. SEMs were conducted to evaluate the microstructure architecture for MMCs.

Thermal Expansion Behavior of the Electroless Copper Coated Cu-SiCp Composites Fabricated via the Conventional Powder Metallurgical Technique

2013 ◽  
Vol 594-595 ◽  
pp. 857-861
Author(s):  
K. Azmi ◽  
M.N. Derman ◽  
A.M. Mustafa Al Bakri ◽  
A.V. Sandu
Keyword(s):  
Silicon Carbide ◽  
Thermal Expansion ◽  
Optical Fibers ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Copper Matrix ◽  
Packaging Materials ◽  
Matrix Composites ◽  
Advanced Packaging ◽  
Silicon Carbide Particles

The introduction of the metal matrix composites as the advanced electronic packaging materials is highly anticipated because their thermal properties can be engineered to match those of semiconductors, ceramics substrates and optical fibers. Among these advanced packaging materials, silicon carbide particles reinforced copper matrix (Cu-SiCp) composites are highly rated due to the high thermal conductivity of copper and low coefficient of thermal expansion (CTE) of silicon carbide. However, the Cu-SiCp composites fabricated via the conventional powder metallurgy (PM) technique usually have immature thermophysical properties due to the weak bonding between the copper matrix and the SiCp reinforcement. In order to improve the bonding between the two constituents, the SiCp were coated with copper via electroless coating process prior to PM fabrication processes. Based on the experimental results, The CTE and porosity of the Cu-SiCp composites were significantly affected by the volume fraction of SiCp. Furthermore, the CTE and porosity of the Cu-Coated Cu-SiCp composites were significantly lower than the non-Coated Cu-SiCp composites. These differences were mainly contributed by the nature of the bonding between the copper matrix and SiCp reinforcement.

Preparation of Electron Transparent Metal-Matrix Composites

1968 ◽  
Vol 26 ◽  
pp. 334-335 ◽  
Author(s):  
M. R. Pinnel ◽  
A. Lawley
Keyword(s):  
Stainless Steel ◽  
Load Transfer ◽  
Volume Fraction ◽  
Steel Wire ◽  
Initial Step ◽  
Interfacial Region ◽  
Matrix Composites ◽  
Specific Test ◽  
The Matrix ◽  
The One

Numerous phenomenological descriptions of the mechanical behavior of composite materials have been developed. There is now an urgent need to study and interpret deformation behavior, load transfer, and strain distribution, in terms of micromechanisms at the atomic level. One approach is to characterize dislocation substructure resulting from specific test conditions by the various techniques of transmission electron microscopy. The present paper describes a technique for the preparation of electron transparent composites of aluminum-stainless steel, such that examination of the matrix-fiber (wire), or interfacial region is possible. Dislocation substructures are currently under examination following tensile, compressive, and creep loading. The technique complements and extends the one other study in this area by Hancock.The composite examined was hot-pressed (argon atmosphere) 99.99% aluminum reinforced with 15% volume fraction stainless steel wire (0.006″ dia.).Foils were prepared so that the stainless steel wires run longitudinally in the plane of the specimen i.e. the electron beam is perpendicular to the axes of the wires. The initial step involves cutting slices ∼0.040″ in thickness on a diamond slitting wheel.

Deformation at interfaces of Ti-6Al-4V/SiC fiber composites

1992 ◽  
Vol 50 (1) ◽  
pp. 158-159
Author(s):  
Warren J. Moberly ◽  
Daniel B. Miracle ◽  
S. Krishnamurthy
Keyword(s):  
Thermal Stresses ◽  
Load Transfer ◽  
Coefficient Of Thermal Expansion ◽  
Hot Isostatic Pressing ◽  
Matrix Composites ◽  
Ongoing Research ◽  
Aerospace Applications ◽  
Sic Fiber ◽  
The Matrix ◽  
Intermetallic Matrix Composites

Titanium-aluminum alloy metal matrix composites (MMC) and Ti-Al intermetallic matrix composites (IMC), reinforced with continuous SCS6 SiC fibers are leading candidates for high temperature aerospace applications such as the National Aerospace Plane (NASP). The nature of deformation at fiber / matrix interfaces is characterized in this ongoing research. One major concern is the mismatch in coefficient of thermal expansion (CTE) between the Ti-based matrix and the SiC fiber. This can lead to thermal stresses upon cooling down from the temperature incurred during hot isostatic pressing (HIP), which are sufficient to cause yielding in the matrix, and/or lead to fatigue from the thermal cycling that will be incurred during application, A second concern is the load transfer, from fiber to matrix, that is required if/when fiber fracture occurs. In both cases the stresses in the matrix are most severe at the interlace.

Effect of Titanium Carbide Particles on Mechanical Properties of Aluminum Matrix Composites

2017 ◽  
Vol 5 (2) ◽  
pp. 20-30
Author(s):  
Zaman Khalil Ibrahim
Keyword(s):  
Mechanical Properties ◽  
Titanium Carbide ◽  
Compression Strength ◽  
Volume Fraction ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Powder Metallurgy Technique ◽  
Carbide Particles ◽  
Properties Of Composites

In this research aluminum matrix composites (AMCs) was reinforced by titanium carbide (TiC) particles and was produced. Powder metallurgy technique (PM) has been used to fabricate AMCs reinforced with various amounts (0%, 4%, 8%, 12%, 16% and 20% volume fraction) of TiC particles to study the effect of different volume fractions on mechanical properties of the Al-TiC composites. Measurements of compression strength and hardness showed that mechanical properties of composites increased with an increase in volume fraction of TiC Particles. Al-20 % vol. TiC composites exhibited the best properties with hardness value (97HRB) and compression strength value (275Mpa).

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