Microstructural Difference between Unreinforced Canning of TC17 Alloy and the Matrix in SiCf/TC17 Composite Fabricated by HIP Process

2016 ◽  
Vol 849 ◽  
pp. 402-408
Author(s):  
Min Juan Wang ◽  
Hao Huang ◽  
Si Qing Li ◽  
Hu Li ◽  
Chuan Xie ◽  
...  
Keyword(s):  
Lamellar Structure ◽  
Hot Isostatic Pressing ◽  
Matrix Alloy ◽  
Carbon Layer ◽  
Sic Fiber ◽  
The Matrix ◽  
Transus Temperature ◽  
The Difference ◽  
Hip Process ◽  
Stabilizing Element

Continuous unidirectional SiCf/TC17 composite has been fabricated by hot isostatic pressing (HIP). After consolidation, the TC17 canning (the unreinforced ambient portion of the specimen) showed an equiaxed microstructure, whereas the matrix of SiCf/TC17 composite (deposited on the continuous SiC fibers by magnetron sputtering) exhibited a typical lamellar structure. In this work, the heat treatments under different condition, XRD, SEM and WDS have been employed to characterize and analyze the microstructural difference. The results indicated that the difference in β transus temperature (Tβ) between the canning and matrix of TC17 alloy induced the microstructural diversity. The introduction of C element (an intensive α stabilizing element) into the matrix alloy may be ascribed to the diffusion of carbon layer at the surface of SiC fiber. As a result, Tβ of matrix TC17 alloy increased to above 1000 °C, much higher than that of the canning TC17 alloy (890 °C). The investigation of microstructure difference reveals the microstructure evolution in SiCf/TC17 composite, which can provide an effective reference for following processing design.

TEM characterization of reaction zone in a SiC fiber-reinforced titanium alloy

1988 ◽  
Vol 46 ◽  
pp. 738-739
Author(s):  
G. Das ◽  
R. E. Omlor
Keyword(s):  
Titanium Alloys ◽  
Reaction Zone ◽  
Carbon Layer ◽  
Fiber Reinforced ◽  
Reaction Products ◽  
Sic Fibers ◽  
Sic Fiber ◽  
The Matrix ◽  
Immense Potential

Fiber reinforced titanium alloys hold immense potential for applications in the aerospace industry. However, chemical reaction between the fibers and the titanium alloys at fabrication temperatures leads to the formation of brittle reaction products which limits their development. In the present study, coated SiC fibers have been used to evaluate the effects of surface coating on the reaction zone in the SiC/IMI829 system.IMI829 (Ti-5.5A1-3.5Sn-3.0Zr-0.3Mo-1Nb-0.3Si), a near alpha alloy, in the form of PREP powder (-35 mesh), was used a茸 the matrix. CVD grown AVCO SCS-6 SiC fibers were used as discontinuous reinforcements. These fibers of 142μm diameter contained an overlayer with high Si/C ratio on top of an amorphous carbon layer, the thickness of the coating being ∽ 1μm. SCS-6 fibers, broken into ∽ 2mm lengths, were mixed with IMI829 powder (representing < 0.1vol%) and the mixture was consolidated by HIP'ing at 871°C/0. 28GPa/4h.

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.

Interaction of elements in carbon-graphite—Al—Mg—Zn—Cu melt system under combined action of temperature and pressure

2021 ◽  
pp. 514-518
Author(s):  
N.Yu. Miroshkin ◽  
V.A. Gulevsky ◽  
S.N. Tsurikhin ◽  
A.I. Bogdanov ◽  
L.M. Gurevich ◽  
...  
Keyword(s):  
Matrix Alloy ◽  
Impregnation Process ◽  
Active Elements ◽  
Cu Alloy ◽  
Inner Surface ◽  
The Matrix ◽  
Combined Action ◽  
Temperature And Pressure ◽  
The Difference ◽  
Titanium Compounds

Redistribution of chemically active elements is established on its inner surface of pores and at the interface with the alloy when impregnating carbon-graphite framework with Al—Mg—Zn—Cu alloy at temperature of 800 °C under pressure of up to 3 MPa. In this case, change in the solubility of melt elements in aluminum is possible as result of the combined action of temperature and pressure in the impregnation process, created due to the difference in the coefficients of thermal and thermal expansion of the matrix alloy, and the material of the impregnation device during impregnation. Titanium compounds are found in the pores filled with metal that are not added to the matrix alloy, but are formed as result of the contact of the matrix alloy melt with the walls of the impregnation device.

Microstructural and basic mechanical characteristics of ZA27 alloy-based nanocomposites synthesized by mechanical milling and compocasting

2018 ◽  
Vol 53 (15) ◽  
pp. 2033-2046 ◽  
Author(s):  
Biljana Bobić ◽  
Aleksandar Vencl ◽  
Jovana Ružić ◽  
Ilija Bobić ◽  
Zvonko Damnjanović
Keyword(s):  
Yield Strength ◽  
Mechanical Milling ◽  
Metal Matrix ◽  
Matrix Alloy ◽  
Compressive Yield Strength ◽  
Za27 Alloy ◽  
The Matrix ◽  
The Difference ◽  
Ball Milling Technique ◽  
Semi Solid

Particulate nanocomposites with the base of ZA27 alloy were synthesized using an innovative route, which includes mechanical milling and compocasting. Scrap from the matrix alloy and ceramic nanoreinforcements were mechanically milled using the ball-milling technique, which led to the formation of composite microparticles. The use of these particles in the compocasting process provided better wettability of ceramic nanoreinforcements in the semi-solid metal matrix, which resulted in a relatively good dispersion of the nanoreinforcements in nanocomposite castings. The presence of nanoreinforcements led to the grain refinement in the matrix of nanocomposites. The mechanical properties of the synthesized nanocomposites are improved and compared with the properties of the metal matrix. The observed increase in the hardness of nanocomposites with Al2O3 nanoreinforcements (20–30 nm) was 6.5% to 10.8%, while the yield strength of these nanocomposites has increased by 12.2% to 23.2%. The hardness and compressive yield strength of the nanocomposites with Al2O3 nanoparticles (100 nm) increased by 1.7% to 8.0% and 2.3% to 8.3%, respectively. The increase in hardness of the nanocomposites with SiC nanoparticles (50 nm) was 11.5% to 20.6%, while the increase in the yield strength was 15.6% to 24.5%. The greatest contribution to the overall strengthening in the synthesized nanocomposites is the result of increased dislocation density due to the difference in coefficients of thermal expansion for the matrix alloy and nanoreinforcements.

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.

Microstructural analysis of fiber coatings and reaction zones in Ti-14Al-21Nb/SiC composites

1990 ◽  
Vol 48 (4) ◽  
pp. 198-199
Author(s):  
Ernest L. Hall ◽  
Ann M. Ritter ◽  
Nathan Lewis
Keyword(s):  
Titanium Aluminide ◽  
Hot Isostatic Pressing ◽  
Microstructural Analysis ◽  
Analytical Electron Microscopy ◽  
Aircraft Engine ◽  
Matrix Alloy ◽  
Ion Milling ◽  
The Matrix ◽  
Reaction Zones ◽  
Sic Composites

Titanium and titanium aluminide fibrous composites are currently under consideration for use in aircraft engine and other applications, and their fabrication, microstructure, and properties are under active investigation. These composites can exhibit enhanced strength relative to the unreinforced matrix alloy, but ductilities are often limited, especially at room temperature. This limited ductility may be related to the formation of brittle reaction zones between the fiber and the matrix during fabrication, heat treatment, or use. In this study, the reaction zones formed during fabrication of a Ti-14 wt. pet. Al-21 wt. pet. Nb (Ti- 142l)/SiC composite were studied using analytical electron microscopy (AEM). The composites were fabricated by plasma-spraying Ti-1421 powder onto a drum wound with SCS-6 SiC fiber obtained from Textron Specialty Materials. The tapes were then stacked and consolidated into 4-ply composites by hot isostatic pressing. After fabrication, samples were prepared for AEM analysis by ion milling.

Effect of Y2O3 Coating on the Interface and Mechanical Properties of SiC Fiber Reinforced GH4738 Composites

2017 ◽  
Vol 898 ◽  
pp. 604-608 ◽  
Author(s):  
Pei Huan Li ◽  
Yong Zhang ◽  
Xuan Hui Qu
Keyword(s):  
Mechanical Properties ◽  
Hot Isostatic Pressing ◽  
Tensile Tests ◽  
Interfacial Reactions ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Sic Fiber ◽  
Elevated Temperature Tensile ◽  
Barrier Coating ◽  
The Matrix

To prevent the strong interfacial reactions in SiC fiber reinforced nickel-based superalloys matrix composites, yttrium oxide (Y2O3) was used as the barrier coating by reaction magnetron sputtering method. Compared with the composites without coating, after the high temperature hot isostatic pressing (HIP), Y2O3 coating effectively protected the SiC fibers from the interfacial reactions, and no element diffusion can be observed between the fibers and the matrix. The elevated temperature tensile tests were performed on both SiC/GH4738 and SiC/Y2O3/GH4738 composite. The results indicated that the strength of the composites with Y2O3 coating can increase about 35% in comparison with the composites without coating.

scholarly journals The Difference of Lamellar Structure Formation between Ti-45Al-5.4V-3.6Nb-Y Alloy and Ti-44Al-4Nb-4V-0.3Mo-Y Alloy

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 566
Author(s):  
Jianchao Han ◽  
Shuzhi Zhang ◽  
Changjiang Zhang ◽  
Fantao Kong ◽  
Yuyong Chen ◽  
...  
Keyword(s):  
Structure Formation ◽  
Phase Field ◽  
Lamellar Structure ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Common Factor ◽  
Β Phase ◽  
The Common ◽  
The Difference ◽  
Stabilizing Element

In this study, the effect factors on the formation of lamellar structure for Ti-45Al-5.4V-3.6Nb-Y alloy and Ti-44Al-4Nb-4V-0.3Mo-Y alloy is discussed in detail. During heat treatment in different procedures, temperature was the common factor influencing the formation of lamellar structures of Ti-45Al-5.4V-3.6Nb-Y and Ti-44Al-4Nb-4V-0.3Mo-Y alloys. In the range of 1230 °C and 1300 °C, the volume fraction of lamellar structure in Ti-45Al-5.4V-3.6Nb-Y alloy was proportional to the annealing temperature. However, between 1210 °C and 1260 °C, the volume fraction of lamellar structure in Ti-44Al-4Nb-4V-0.3Mo-Y alloy deceased when temperature was located in the α + γ + β triple phase field and then increased when temperature was in the α + β binary phase field. Besides the influence of temperature, the lamellar structure formation of Ti-44Al-4Nb-4V-0.3Mo-Y alloy was also affected by the β-phase stabilizing element.

Tem analysis of multiple-energy arsenic implanted and Rta'd silicon

1987 ◽  
Vol 45 ◽  
pp. 246-247
Author(s):  
R.A. Herring
Keyword(s):  
Device Fabrication ◽  
High Concentration ◽  
Tem Analysis ◽  
Defect Clusters ◽  
High Fluences ◽  
Small Defect ◽  
Before And After ◽  
The Matrix ◽  
The Difference ◽  
Factor Type

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.

Development of Prolonged Delivery of Tramadol and Dissolution Translation by Statistical Data Treatment

2011 ◽  
Vol 4 (1) ◽  
pp. 1331-1337
Author(s):  
P B Parejiya ◽  
B S Barot ◽  
P K Shelat
Keyword(s):  
Drug Release ◽  
Study Data ◽  
Stability Study ◽  
Dissolution Time ◽  
Matrix Tablet ◽  
Burst Effect ◽  
The Matrix ◽  
The Mean ◽  
The Difference ◽  
Dissolution Efficiency

The present study was carried out to fabricate a prolonged design for tramadol using Kollidon SR (Polyvinyl acetate and povidone based matrix retarding polymer). Matrix tablet formulations were prepared by direct compression of Kollidon SR of a varying proportion with a fixed percentage of tramadol. Tablets containing a 1:0.5 (Drug: Kollidon SR) ratio exhibited a rapid rate of drug release with an initial burst effect. Incorporation of more Kollidon SR in the matrix tablet extended the release of drug with subsequent minimization of the burst effect as confirmed by the mean dissolution time, dissolution efficiency and f2 value. Among the formulation batches, a direct relationship was obtained between release rate and the percentage of Kollidon SR used. The formulation showed close resemblance to the commercial product Contramal and compliance with USP specification. The results were explored and explained by the difference of micromeritic characteristics of the polymers and blend of drug with excipients. Insignificant effects of various factors, e.g. pH of dissolution media, ionic strength, speed of paddle were found on the drug release from Kollidon-SR matrix. The formulation followed the Higuchi kinetic model of drug release. Stability study data indicated stable character of Batch T6 after short-term stability study.

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