Author: Lixin Wu
Publisher:
ISBN:
Category : Metallic composites
Languages : en
Pages : 170
Book Description
A Study of the Mechanical Properties of Ti(Al,O)/Al2O3 and Ti3Al(O)/TiAl(O)/Al2O3 Composites with Different Volume Fractions of Al2O3
Author: Lixin Wu
Publisher:
ISBN:
Category : Metallic composites
Languages : en
Pages : 170
Book Description
Publisher:
ISBN:
Category : Metallic composites
Languages : en
Pages : 170
Book Description
A Study of the Interfacial Stability of Ti/Al2O3, Ti3Al/Al2O3 and TiAl/Al2O3 Composite Materials
Author: Joel Alan DeKock
Publisher:
ISBN:
Category :
Languages : en
Pages : 352
Book Description
This thesis is a study of the interfacial stability of the Ti-Base metal matrix composites Ti/Al2O3, Ti3Al/Al2O3 and TiAl/Al2O3. Interfacial stability is discussed in view of the importance of thermodynamics and kinetics as the primary considerations which govern the type of stability observed. From a thermodynamics approach, the application of phase equilibrium diagrams is essential in the design of composite systems. A classification system, with reference to phase equilibrium, is used to describe the type of interfacial stability observed for the composites studied. In addition, electron-probe microanalysis, atom-probe field ion microscopy and X-ray diffraction results are used to establish Ti-Al-O phase relations for the temperature range 900-to-1250 deg C. The kinetics of interfacial stability is discussed with particular attention given to the kinetic considerations; diffusion path, phase formation sequence, steady-state layer growth and interface morphology. Kinetic results in the form of parabolic growth constants and calculated interdiffusion coefficients are presented.
Publisher:
ISBN:
Category :
Languages : en
Pages : 352
Book Description
This thesis is a study of the interfacial stability of the Ti-Base metal matrix composites Ti/Al2O3, Ti3Al/Al2O3 and TiAl/Al2O3. Interfacial stability is discussed in view of the importance of thermodynamics and kinetics as the primary considerations which govern the type of stability observed. From a thermodynamics approach, the application of phase equilibrium diagrams is essential in the design of composite systems. A classification system, with reference to phase equilibrium, is used to describe the type of interfacial stability observed for the composites studied. In addition, electron-probe microanalysis, atom-probe field ion microscopy and X-ray diffraction results are used to establish Ti-Al-O phase relations for the temperature range 900-to-1250 deg C. The kinetics of interfacial stability is discussed with particular attention given to the kinetic considerations; diffusion path, phase formation sequence, steady-state layer growth and interface morphology. Kinetic results in the form of parabolic growth constants and calculated interdiffusion coefficients are presented.
High Temperature Mechanical Characterization and Analysis of Al2O3 /Al2O3 Composition
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781720571773
Category :
Languages : en
Pages : 36
Book Description
Sixteen ply unidirectional zirconia coated single crystal Al2O3 fiber reinforced polycrystalline Al2O3 was tested in uniaxial tension at temperatures to 1400 C in air. Fiber volume fractions ranged from 26 to 31%. The matrix has primarily open porosity of approximately 40%. Theories for predicting the Young's modulus, first matrix cracking stress, and ultimate strength were applied and evaluated for suitability in predicting the mechanical behavior of Al2O3/Al2O3 composites. The composite exhibited pseudo tough behavior (increased area under the stress/strain curve relative to monolithic alumina) from 22 to 1400 C. The rule-of-mixtures provides a good estimate of the Young's modulus of the composite using the constituent properties from room temperature to approximately 1200 C for short term static tensile tests in air. The ACK theory provides the best approximation of the first matrix cracking stress while accounting for residual stresses at room temperature. Difficulties in determining the fiber/matrix interfacial shear stress at high temperatures prevented the accurate prediction of the first matrix cracking stress above room temperature. The theory of Cao and Thouless, based on Weibull statistics, gave the best prediction for the composite ultimate tensile strength.Gyekenyesi, John Z. and Jaskowiak, Martha H.Glenn Research CenterHIGH TEMPERATURE; ALUMINUM OXIDES; FIBER COMPOSITES; POLYCRYSTALS; CERAMIC FIBERS; TEMPERATURE EFFECTS; CERAMIC MATRIX COMPOSITES; MODULUS OF ELASTICITY; STRESS-STRAIN RELATIONSHIPS; WEIBULL DENSITY FUNCTIONS; TENSILE STRENGTH; TENSILE TESTS; FIBER-MATRIX INTERFACES; HIGH TEMPERATURE TESTS; ZIRCONIUM OXIDES
Publisher: Createspace Independent Publishing Platform
ISBN: 9781720571773
Category :
Languages : en
Pages : 36
Book Description
Sixteen ply unidirectional zirconia coated single crystal Al2O3 fiber reinforced polycrystalline Al2O3 was tested in uniaxial tension at temperatures to 1400 C in air. Fiber volume fractions ranged from 26 to 31%. The matrix has primarily open porosity of approximately 40%. Theories for predicting the Young's modulus, first matrix cracking stress, and ultimate strength were applied and evaluated for suitability in predicting the mechanical behavior of Al2O3/Al2O3 composites. The composite exhibited pseudo tough behavior (increased area under the stress/strain curve relative to monolithic alumina) from 22 to 1400 C. The rule-of-mixtures provides a good estimate of the Young's modulus of the composite using the constituent properties from room temperature to approximately 1200 C for short term static tensile tests in air. The ACK theory provides the best approximation of the first matrix cracking stress while accounting for residual stresses at room temperature. Difficulties in determining the fiber/matrix interfacial shear stress at high temperatures prevented the accurate prediction of the first matrix cracking stress above room temperature. The theory of Cao and Thouless, based on Weibull statistics, gave the best prediction for the composite ultimate tensile strength.Gyekenyesi, John Z. and Jaskowiak, Martha H.Glenn Research CenterHIGH TEMPERATURE; ALUMINUM OXIDES; FIBER COMPOSITES; POLYCRYSTALS; CERAMIC FIBERS; TEMPERATURE EFFECTS; CERAMIC MATRIX COMPOSITES; MODULUS OF ELASTICITY; STRESS-STRAIN RELATIONSHIPS; WEIBULL DENSITY FUNCTIONS; TENSILE STRENGTH; TENSILE TESTS; FIBER-MATRIX INTERFACES; HIGH TEMPERATURE TESTS; ZIRCONIUM OXIDES
Processing, Microstructure and Mechanical Properties OfTixAly/Al2O3 and Al2Ti4C2/TixAly/Al2O3/TiC Composites
Author: Zhihong Cai
Publisher:
ISBN:
Category : Ceramic metals
Languages : en
Pages : 110
Book Description
Publisher:
ISBN:
Category : Ceramic metals
Languages : en
Pages : 110
Book Description
The Processing and Characterization of FeCrAlY/Al2O3 Composites
Author: Julian Escareno Ambriz
Publisher:
ISBN:
Category : Metallic composites
Languages : en
Pages : 302
Book Description
Publisher:
ISBN:
Category : Metallic composites
Languages : en
Pages : 302
Book Description
Experimental and Numerical Studies of Aluminum-Alumina Composites
Author: Pradeep Gudlur
Publisher:
ISBN:
Category :
Languages : en
Pages : 182
Book Description
The preliminary goal of this study is to determine the effects of processing conditions, compositions and microstructural morphologies of the constituents on the physical and thermo-mechanical properties of alumina (Al2O3) reinforced aluminum (Al) composites. Composites with 0, 5, 10, 20 and 25 vol% Al2O3 were manufactured using powder metallurgy method. The elastic properties (Young's and shear modulus) and the coefficient of thermal expansion (CTE) of the composites were determined using Resonant Ultrasound Spectroscopy (RUS) and Thermo Mechanical Analyzer (TMA) respectively at various temperatures. Increasing compacting pressure improved relative density (or lowered porosity) of the composites. Furthermore, increasing the Al2O3 vol% in the composite increased the elastic moduli and reduced the CTE of the composites. Increasing the testing temperature from 25 to 450 °C, significantly reduced the elastic moduli of the composites, while the CTE of the composites changed only slightly with temperatures. Secondly, the goal of this study is to determine the effect of microstructures on the effective thermo-mechanical properties of the manufactured Al-Al2O3 composites using finite element (FE) method. Software OOF was used to convert the SEM micrographs of the manufactured composites to FE meshed models, which were then used to determine the effective elastic modulus and CTE. It was observed that, effective modulus dropped by 19.7% when porosity increased by 2.3%; while the effective CTE was mildly affected by the porosity. Additionally, the effect of residual stress on the effective thermo-mechanical properties was studied, and the stress free temperature of the composites was determined. Another objective of this study is to examine the stress-strain response of Al-Al2O3 composites due to compressive loads at various temperatures. Elastic modulus, yield stress and strain hardening parameters were determined from the stress-strain curves and their dependency on temperature, porosity and volume fraction were studied. The experimental results were compared with the numerical results. It was observed that high-localized stresses were present near the pores and at the interfaces between Al and Al2O3 constituents. Finally, functionally graded materials (FGMs) with varyingAl2O3 concentration (0, 5and 10 vol%) in Al were manufactured; and their stress-strain response and CTE were determined at various temperatures. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151205
Publisher:
ISBN:
Category :
Languages : en
Pages : 182
Book Description
The preliminary goal of this study is to determine the effects of processing conditions, compositions and microstructural morphologies of the constituents on the physical and thermo-mechanical properties of alumina (Al2O3) reinforced aluminum (Al) composites. Composites with 0, 5, 10, 20 and 25 vol% Al2O3 were manufactured using powder metallurgy method. The elastic properties (Young's and shear modulus) and the coefficient of thermal expansion (CTE) of the composites were determined using Resonant Ultrasound Spectroscopy (RUS) and Thermo Mechanical Analyzer (TMA) respectively at various temperatures. Increasing compacting pressure improved relative density (or lowered porosity) of the composites. Furthermore, increasing the Al2O3 vol% in the composite increased the elastic moduli and reduced the CTE of the composites. Increasing the testing temperature from 25 to 450 °C, significantly reduced the elastic moduli of the composites, while the CTE of the composites changed only slightly with temperatures. Secondly, the goal of this study is to determine the effect of microstructures on the effective thermo-mechanical properties of the manufactured Al-Al2O3 composites using finite element (FE) method. Software OOF was used to convert the SEM micrographs of the manufactured composites to FE meshed models, which were then used to determine the effective elastic modulus and CTE. It was observed that, effective modulus dropped by 19.7% when porosity increased by 2.3%; while the effective CTE was mildly affected by the porosity. Additionally, the effect of residual stress on the effective thermo-mechanical properties was studied, and the stress free temperature of the composites was determined. Another objective of this study is to examine the stress-strain response of Al-Al2O3 composites due to compressive loads at various temperatures. Elastic modulus, yield stress and strain hardening parameters were determined from the stress-strain curves and their dependency on temperature, porosity and volume fraction were studied. The experimental results were compared with the numerical results. It was observed that high-localized stresses were present near the pores and at the interfaces between Al and Al2O3 constituents. Finally, functionally graded materials (FGMs) with varyingAl2O3 concentration (0, 5and 10 vol%) in Al were manufactured; and their stress-strain response and CTE were determined at various temperatures. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151205
High Temperature Mechanical Characterization and Analysis of Al2O3 /Al2O3 Composition
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 38
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 38
Book Description
Mechanical Working of (Al2O3)p/Al Composite
Author: Jae Chul Lee
Publisher:
ISBN:
Category : Aluminum alloys
Languages : en
Pages : 534
Book Description
Publisher:
ISBN:
Category : Aluminum alloys
Languages : en
Pages : 534
Book Description
TEM Study of Interfacial Reactions and Precipitation Mechanisms in Al2O3 Short Fiber Or High Volume Fraction SiC Particile Reinforced Al-4Cu-1Mg-0.5Ag Squeeze-cast Composites
Author: Cyril Cayron
Publisher:
ISBN: 9783905594232
Category : Metallic composites
Languages : en
Pages : 170
Book Description
Publisher:
ISBN: 9783905594232
Category : Metallic composites
Languages : en
Pages : 170
Book Description
The Effect of Fiber Volume Fraction on the Properties of Al/[alpha] - Al2O3 Metal Matrix Composites
Author: Sailen Choudhury
Publisher:
ISBN:
Category : Metallic composites
Languages : en
Pages : 232
Book Description
Publisher:
ISBN:
Category : Metallic composites
Languages : en
Pages : 232
Book Description