XD™ Titanium Aluminide Composites

1988 ◽  
Vol 120 ◽  
Author(s):  
L. Christodoulou ◽  
P. A. Parrish ◽  
C. R. Crowe
Keyword(s):  
Titanium Aluminide ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Measurement Techniques ◽  
Physical Property ◽  
Casting Process ◽  
Matrix Composition ◽  
Al Alloy ◽  
Matrix Composites ◽  
New Generation

AbstractThe advantages of reinforcing metals with ceramic particles to produce metal matrix composites are well known. The behavior of discontinuously reinforced intermetallic compounds, however, has not been extensively studied. Martin Marietta Laboratories has produced a new generation of discontinuously reinforced titanium aluminide composites using a proprietary casting process known as XD™ technology. These new materials possess enhanced properties at room and elevated temperatures and may be cast, extruded, or forged. The effects of matrix composition, reinforcing phase, and thermal mechanical processing on properties have been studied using optical and various electron microscopy and mechanical and physical property measurement techniques to characterize the alloys. To date, most work has been done on a two-phased lamellar Ti-45 a/o Al alloy reinforced with TiB2 ceramic having an equiaxed morphology. Data on temperature dependence of the dynamic Young's modulus, coefficient of thermal expansion, deformation and fracture behavior, and microstructure are presented.

Processing of Nickel-Copper Coated Carbon Fibre Rods Reinforced Al6082/4% Al2O3/2%Gr Matrix Composites

2019 ◽  
Vol 969 ◽  
pp. 727-731
Author(s):  
Marise Srinivasu ◽  
R. Suresh ◽  
L. Shivaramu
Keyword(s):  
Carbon Fibre ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Casting Process ◽  
Al Alloy ◽  
Fibre Reinforcement ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
Aluminum Metal ◽  
Coated Carbon

Aluminum metal matrix with carbon fibre reinforcement composites are potential materials for automotive, aerospace and electronics industries. The interaction between Al matrix and carbon fibre reinforcement, plays vibrant role to decide the properties of the Metal Matrix Composites (MMC’s). However, interaction between Al alloy matrix and carbon fibre is forming an Aluminum Carbide (Al4C3) at higher temperature (>650°C). This consequence degrades the mechanical properties and promotes corrosion. To overcome corrosion problem and improve the composite properties, metallic coating on carbon rod is very vital. In the present study, aluminum metal matrix composites (Al6082/4%Al2O3+2%Gr) were developed with coated carbon fibre rod using stir casting process. Carbon fibre rods of 3 mm diameter is coated with nickel by electro less process and then copper coating done by electrolytic process. The bonding between matrix and reinforcement was observed in SEM and EDAX analysis. The results indicates the absent of Al4C3 formation.

scholarly journals Synthesis, Characterization and Testing of Al Alloy Based Hybrid Composite Materials

2019 ◽  
Vol 9 (2S2) ◽  
pp. 139-142
Keyword(s):  
Composite Materials ◽  
Casting Process ◽  
Stir Casting ◽  
Homogeneous Distribution ◽  
Al Alloy ◽  
Matrix Composites ◽  
Boron Carbide B4c ◽  
Weight Proportion

The developments in the area of aerospace, advancing activities in aircraft field and automotive industry emerges the exploit of new materials. In such applications, the role of Metal Matrix Composites (MMCs) is inevitable. In the proposed article, the fabrication of Al (6351) alloy reinforced with SiC and varying weight proportion of Boron Carbide (B4C) was done through stir casting process. The characterization of prepared composite materials is evaluated to ensure the homogeneous distribution of reinforced particulates in Al matrix. The existence of alloying elements and their mapping is done through EDS. Moreover, the enhancement of physical and mechanical behavior of the fabricated composites is also discussed in detail.

scholarly journals Evaluation of Mechanical and Thermal Properties of Aluminium-7475 Reinforced with Graphite and Fly ash

2021 ◽  
Vol 309 ◽  
pp. 01186
Author(s):  
K Sunil Kumar Reddy ◽  
M Kannan ◽  
R Karthikeyan
Keyword(s):  
Wear Resistance ◽  
Fly Ash ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Coefficient Of Thermal Expansion ◽  
Casting Process ◽  
Mechanical And Thermal Properties ◽  
Matrix Composites ◽  
Graphite Content ◽  
Weight Percentage

The aluminium is used for variety of reasons and they are known for their improved strength, stiffness, wear resistance which are useful in the marine, space, transport, automobile related industries. When aluminium reinforced with ceramic materials like fly ash, silicon carbide, tungsten carbide, boron carbide, fired bricks then a composite of better plastic forming capability, excellent heat and wear resistance will be formed. The objective of the experiment is to assess the thermal and mechanical properties of the Aluminium Metal Matrix Composites (AMMCs) when reinforced with ceramics. Aluminium (Al-7475) based metal matrix composites reinforced with varying weight percentage of Graphite(Gr) (3%, 6%, 9% and 12%) and fly ash being constant (10wt%) by the stir casting process. The composites tensile strength and hardness improved with the amount of graphite content improved in weight percentage up to 9% then decreased. While the composite’s Thermal Conductivity(TC) and Coefficient of Thermal Expansion(CTE) varying temperature range from 50°Cto 300°C reduces with increase in weight percentage of the graphite content.

Cross-section TEM sample preparation of Ti-6Al-4V/SCS6 (SiC) fiber-reinforced composites

1992 ◽  
Vol 50 (1) ◽  
pp. 402-403
Author(s):  
Warren J. Moberly ◽  
Scott Apt
Keyword(s):  
Thermal Processing ◽  
Titanium Aluminide ◽  
Thermal Stresses ◽  
Coefficient Of Thermal Expansion ◽  
Hot Isostatic Pressing ◽  
Matrix Composites ◽  
Sic Fiber ◽  
Structural Applications ◽  
The Matrix ◽  
Intermetallic Matrix Composites

Titanium-based metal matrix composites (MMC) and titanium aluminide intermetallic matrix composites (IMC) have been selected for future aerospace structural applications. The mechanical integrity of these composites are dictated by the thermodynamic stability of the fiber / matrix interface and deformation that occurs at the interface. The thermal processing incurred during hot-isostatic-pressing (HIP) results in the formation of intermetallic phases, with detrimental mechanical properties, at the interface. In addition, the thermal processing results in residual stresses due to the mismatch in coefficient of thermal expansion (CTE) between the Ti-based matrix and the SiC fiber. In some cases the thermal stresses are sufficient to cause yielding in the matrix, and/or lead to fatigue from the thermal cycling that will be incurred during application.

Tensile Properties and Plasticity of Semi-Solid Cast 6061 Al Alloy at Elevated Temperatures

2014 ◽  
Vol 496-500 ◽  
pp. 366-370
Author(s):  
Sukrit Songkuea ◽  
Patcharee Sripan ◽  
Sirikul Wisutmethangoon ◽  
Jessada Wannasin ◽  
Thawatchai Plookphol
Keyword(s):  
Tensile Properties ◽  
Elevated Temperatures ◽  
Casting Process ◽  
Tensile Tests ◽  
Strain Hardening Exponent ◽  
Al Alloy ◽  
Globular Structure ◽  
Elongation At Break ◽  
Semi Solid ◽  
6061 Al Alloy

The purpose of this study was to investigate the tensile properties and plasticity of semi-solid 6061 Al alloy at room and elevated temperatures. The semi-solid 6061 alloy was produced by the Gas Induced Semi-Solid (GISS) technique followed by squeeze casting process. The conventional liquid squeeze cast (CLC) 6061 alloy was also fabricated for comparison. The tensile tests were performed at temperature of 25 °C, 100 °C and 175 °C. The experimental results showed that the UTS, 0.2% yield strength and % elongation at break of the SSM alloy are higher than those of the CLC one at all temperatures. Based on the simple flow law, σt=Kεtn , the strain hardening exponentnand the strength coefficientKof the SSM alloy are lower than those of the CLC. The SSM alloy demonstrates more plasticity than the CLC. The results may be attributed to the more globular structure of the SSM alloy.

scholarly journals Analysis of Surface Roughness and Burr Height in Drilling of Aluminium Matrix Composites using Taguchi Technique

2020 ◽  
Vol 12 (2) ◽  
pp. 173-182
Author(s):  
C. SARALA RUBI ◽  
J. UDAYA PRAKASH
Keyword(s):  
Surface Roughness ◽  
Fly Ash ◽  
Casting Process ◽  
Stir Casting ◽  
Al Alloy ◽  
Matrix Composites ◽  
Taguchi Technique ◽  
Burr Height ◽  
Response Table ◽  
Reinforcing Material

The present research involves the opportunity of utilising the signal to noise (S/N) ratio analysis to set machining factors in the drilling of aluminium alloy LM6-Fly ash composites (AMCs). The purpose of this research is to understand, during drilling of AMCs, the consequences of variables, feed rate, spindle speed, drill material and amount of reinforcing material on surface roughness and burr height. AMCs are formed with LM6 (Al alloy) as continuous component via the stir casting process and fly ash as reinforced content. The Taguchi design strategy is a widely accepted method which is used to produce quality products that require minimum commitment. Likewise, the L27 orthogonal array is used for conducting experiments. The response table, response graphs and analysis of variance (ANOVA) illustrate the prospective atmosphere and the impacts of input process variables. Taguchi technique considerably enhances the drilling operation.

A Review on Optimization of Friction and Wear Parameters (Al Alloy-B4C) Composite Using Taguchi Technique

2015 ◽  
Vol 813-814 ◽  
pp. 491-497
Author(s):  
Vishwanath Prasad ◽  
V.K. Soni ◽  
R.S. Rana
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Coefficient Of Thermal Expansion ◽  
Signal To Noise Ratio ◽  
Matrix Alloy ◽  
Al Alloy ◽  
Matrix Composites ◽  
Sliding Velocity

Metal matrix composites (MMCs) have proved their viability as good alternatives to conventional alloys in high strength and stiffness application in industries like automobile, aerospace and mineral processing. Al metal matrix composites (MMCs) are being considered as a group of advanced materials for their lightweight, low coefficient of thermal expansion, and good wear resistance properties. The optimization of parameter has been done by using different techniques like Taguchi, DOE and their results were verified by ANOVA. Signal-to-noise ratio and Analysis of variance (ANOVA) were used to investigate the influence of parameters on the wear rate. Based on various papers the conclusion of this review paper is to study the influence of applied load, sliding speed and sliding distance on the various parameter such as optimum wear and co-efficient of friction of Al alloy-B4C composite to enhance the quality of product and suggest the best combination of wear parameter which helps to reduce the wear of product with the help of Taguchi method. The wear resistance of the composite was found to be considerably higher than that of the matrix alloy and increased with increasing particle content. The major observation based on reviewed papers is that the major factor in determining the wear rate is load applied followed by distance and sliding velocity whereas distance affects the coefficient of friction to a large extent followed by load and sliding velocity.

Characterization of Fiber/Matrix Interfaces by Transmission Electron Microscopy in Titanium Aluminide/Sic Composites

1992 ◽  
Vol 273 ◽  
Author(s):  
Cecil G. Rhodes
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Titanium Aluminide ◽  
Matrix Composition ◽  
Matrix Composites ◽  
Reaction Products ◽  
Alloy Matrix ◽  
Transmission Electron ◽  
Matrix Reinforcement ◽  
Sic Composites

ABSTRACTThis paper presents examples of the use of transmission electron microscopy to characterize matrix/reinforcement interaction in titanium aluminide matrix composites reinforced with continuous SCS-6 type SiC. As a result of the high temperature required for consolidating this type composite, reaction products form in the interface. Using diffraction and x-ray energy dispersive spectroscopy techniques, reaction products in Ti3Al and Ti2AINb alloy matrix composites have been identified. TiC1 –x and Ti5 Si3 compounds are common in these composites, with AlTi3C also present depending on consolidation temperature and matrix composition. Residual stress calculations indicate that these reaction products may be subject to cracking during cooling from consolidationtemperatures.

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.

Microstructural characterization of plasma-processed Ti-Al metal matrix composites

1989 ◽  
Vol 47 ◽  
pp. 552-553
Author(s):  
M. G. Burke ◽  
M. N. Gungor ◽  
M. A. Burke
Keyword(s):  
High Temperature ◽  
Titanium Aluminide ◽  
Plasma Processing ◽  
Microstructural Characterization ◽  
High Temperature Strength ◽  
Matrix Composites ◽  
Intermetallic Matrix ◽  
Long Time ◽  
Strength And Stiffness ◽  
Intermetallic Matrix Composites

Intermetallic matrix composites are candidates for ultrahigh temperature service when light weight and high temperature strength and stiffness are required. Recent efforts to produce intermetallic matrix composites have focused on the titanium aluminide (TiAl) system with various ceramic reinforcements. In order to optimize the composition and processing of these composites it is necessary to evaluate the range of structures that can be produced in these materials and to identify the characteristics of the optimum structures. Normally, TiAl materials are difficult to process and, thus, examination of a suitable range of structures would not be feasible. However, plasma processing offers a novel method for producing composites from difficult to process component materials. By melting one or more of the component materials in a plasma and controlling deposition onto a cooled substrate, a range of structures can be produced and the method is highly suited to examining experimental composite systems. Moreover, because plasma processing involves rapid melting and very rapid cooling can be induced in the deposited composite, it is expected that processing method can avoid some of the problems, such as interfacial degradation, that are associated with the relatively long time, high temperature exposures that are induced by conventional processing methods.

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