| Fiber Debonding in Residually Stressed Brittle Matrix Composites |
90 |
|
| Authors:
Panos G. Charalambides; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
 | The competition between initial fiber debonding versus fiber failure marks a crucial event of the microstructural failure process in fiber-reinforced brittle matrix composites. In this study, the role of a thermal residual stress field on the debonding conditions is examined theoretically and analytically. The analysis is based on two critical observations, the first being that the mechanics at the tip of a kink crack are driven only by the singularity ... |
|
| Contributions of Sintering and Coarsening to Densification: A thermodynamic Approach |
90 |
|
| Authors:
F. F. Lange; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
|
| The Fracture Resistance and Strength of Brittle Matrix Composites |
90 |
|
| Authors:
F. Zok; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
|
| Electron Microscopy Studies of Nb-Al2O3 Interfaces Formed by Molecular Beam Epitaxy |
90 |
|
| Authors:
J. Mayer; J. A. Dura; C. P. Flynn; M. Ruehle; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| Niobium films were grown by molecular beam epitaxy on sapphire substrates of different orientations. A unique three-dimensional orientation relationship was determined between the Al2O3 substrate and the niobium film independent of substrate orientation: (0001)(s)//(111)(Nb) and 2 -1 -1 0(s)//1 - 1 0(Nb). This observation is in contrast with topotaxial relationships obtained between Al2O3 particles formed by internal oxidation of NbAl alloys where close- packed planes are parallel: (0001)(s)//(110)(Nb). The atomistic ... |
|
| High-Resolution Electron Microscopy Studies of Nb/Al2O3 Interfaces |
90 |
|
| Authors:
J. Mayer; C. P. Flynn; M. Ruehle; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| Single-crystal niobium films were grown by molecular beam epitaxy (MBE) on (0001)2, (1 -1 0 0)(s) and (1 -2 1 0)(s) sapphire substrates. Cross- sectional specimens with thicknesses of < 20 nm were prepared so that the Nb/ Al2O3 interface could be investigated by high-resolution electron microscopy (HREM). The same unique orientation relationship is obtained for niobium films deposited on differently oriented sapphire substrates: (0001)(s)//(111)(Nb) and 2 -1 -1 0(s)//1 ... |
|
| The Influence of the Reaction Layer Structure and Properties on Ductile Phase Toughening in Titanium Aluminide-Niobium Composites. |
1990 |
|
| Authors:
G. R. Odette; H. E. Deve; C. K. Elliott; A. Hasegawa; G. E. Lucas; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, imc materials and material types:, (nb)p/tial, (tinb)p/tial, nb particulates, nb/tial, particulates, tial matrix, tinb particulates, tinb/tial material characteristics and data fields:, crack growths, debonding, diffusion bondings, fracture work, toughening testing and test conditions:, sem, tem miscellaneous and special technical terms:, interfacial, ternary phase diagrams. |
|
| Models for the Strength of Ductile Matrix Composites. |
1990 |
|
| Authors:
Gang Bao; Francesco Genna; John W. Hutchinson; Robert M. McMeeking; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| Numerical results have been obtained for the plastic flow of a metal matrix composite reinforced by rigid, spheres, cylinders and ellipsoids. aligned geometries have been investigated and 2-d and 3-d cellular calculations carried out using the finite element method. the relative effect of particulates, disks and needles used as reinforcements are compared. needles in aligned arrangements are found to produce the greatest strengthening. additional results are presented from plane strain ... |
|
| Solidification Processing Routes to High Aspect Ratio Reinforcements in Gamma-TiAl. |
1990 |
|
| Authors:
J. J. Valencia; J. P. A. Loefvander; J. Roesler; C. G. Levi; R. Mehrabian; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| Additions of ^5%b and ^9%ta to binary gamma-tial result in the formation of a monoboride isomorphous with tib but containing ta in solid solution. this boride exhibits strongly anisotropic growth from the melt, producing rod-like primary phases which are of potential interest for creep strengthening of the gamma matrix. fibrous borides with aspect ratios larger than ^20 and volume fractions of ^0.12 have been produced in arc-melted ti-48al-9ta-4.3b alloys. creep ... |
|
| Toughening of Intermetallics by Coated Ductile Reinforcements. |
1990 |
|
| Authors:
H. E. Deve; A. G. Evans; R. Mahrabian; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The effects of reinforcement debonding and work hardening on ductile reinforcement toughening of gamma-tial have been examined. debonding product layer or by depositing a thin oxide coating between the reinforcement and matrix. the role of work hardening has been explored by comparing nb reinforcements that exhibits high work hardening with solution hardening with solution hardened ti-nb alloy that exhibits negligible work hardening. it is demonstrated that a high work of ... |
|
| Effects of Plasticity on the Crack Propagation Resistance of a Metal/Ceramic Interface. |
1990 |
|
| Authors:
I. E. Reimanis; B. J. Dalgleish; M. Brahy; M. Ruehle; A. G. Evans; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| Fracture experiments have been conducted on a gold/sapphire interface. the interface is found to fail by interface separation in a nominally "brittle" manner with a critical strain energy release rate. critical dissipation = 50jm(-2), substantially larger than the work of adhesion, w(ad)=0.5jm(-2). evidence of plastic deformation on the gold fracture surface, such as blunting steps and slip steps, suggest that plastic dissipation is the primary contribution to the measured critical ... |
|
| Electron Microscopy Studies of Nb-Al2O3 Interfaces Formed by Molecular Beam Epitaxy. |
1990 |
|
| Authors:
J. Mayer; J. A. Dura; C. P. Flynn; M. Ruehle; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, experimental, mmc materials and material types:, (al2o3)p/nb, al2o3 substrates, al2o3/nb, films, nb fibers, nb films, nb matrix, particulates, plates, substrates material characteristics and data fields:, cte, decohesions, diffusion bondings, growth rates, interfacial energy, internal oxidation, thermal stress testing and test conditions:, hrem, sad, tem, xrd manufacturing:, annealing, fabrications, millings miscellaneous and ... |
|
| The Processing and Mechanical Behavior of an Aluminum Matrix Composite Reinforced With Short Fibers. |
1990 |
|
| Authors:
Y. L. Klipfel; M. Y. He; R. M. McMeeking; A. G. Evans; R. Mehrabian; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| An aluminum alloy composite reinforced with chopped al2o3 fibers randomly oriented in a plane has been produced by a modified squeeze casting process and its mechanical behavior compared with the corresponding behavior of the matrix. the specific characteristics of the compositing process have been examined vis-a-vis the characteristics of liquid metal infiltration into the capillaries of the fiber bundle. the flow stresses in the as-cast composite have been correlated with ... |
|
| The New High-Toughness Ceramics |
NOV 89 |
|
| Authors:
A. G. Evans; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The principal microstructural sources of toughening are reviewed, with emphasis on comparisons between theory and experiment. Process zone mechanisms, such as transformation and microcracking, as well as bridging mechanisms induced by either ductile networks of fiber/whiskers are afforded primary consideration. Microstructural variables that allow toughness optimization are established. |
|
| The Processing and Mechanical Properties of High Temperature/High Performance Composites. Book 1, Section 1: Coatings and Interfaces |
15 OCT 89 |
399 pages |
| Authors:
CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
 | The third annual report of the University Research Initiative project at UCSB on High-Temperature, High-Performance Composites consists of four sections compiled in a total of six books. The first sections is concerned with coatings and interfaces and is expressed in Book 1. The second section focuses on strength and fracture resistance and is found in Books 2 and 3. The third section describes research on flow and creep strength, this ... |
|
| The Processing and Mechanical Properties of High Temperature/High Performance Composites. Book 2, Section 2: Strength and Fracture Resistance |
15 OCT 89 |
392 pages |
| Authors:
CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The third annual report of the University Research Initiative project at UCSB on High-Temperature, High-Performance Composites consists of sections compiled in a total of six books. The first section in Book 1 is concerned with the properties and structure of bimaterial interfaces and the related problem of coating decohesion and cracking. The second section describes research on the strengths and fracture resistance of brittle matrix composites manufactured with fibers, whiskers ... |
|
| The Processing and Mechanical Properties of High Temperature/High Performance Composites. Book 3, Section 2: Strength and Fracture Resistance. Part 2 |
15 OCT 89 |
442 pages |
| Authors:
CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The third annual report of the University Research Initiative project at UCSB on High-Temperature, High-Performance Composites consists of sections compiled in a total of six books. The first section in Book 1 is concerned with the properties and structure of bimaterial interfaces and the related problem of coating decohesion and cracking. The second section describes research on the strengths and fracture resistance of brittle matrix composites manufactured with fibers, whiskers ... |
|
| The Processing and Mechanical Properties of High Temperature/High Performance Composites. Book 4, Section 3: Flow and Creep Strength |
15 OCT 89 |
194 pages |
| Authors:
CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| Substantial activity has been initiated to examine creep strength and ductility during both plastic flow and creep in the presence of reinforcements. The variables of principal interest are the reinforcement aspect ratio and size, as well as their fracture/debond resistance. Papers include: Flow strength and ductility of an aluminum alloy reinforced with SiC particulates; Aspects of the high temperature performance of ceramics and ceramic composites; Brittle-to- ductile transition in silicon ... |
|
| The Processing and Mechanical Properties of High Temperature/High Performance Composites. Book 5, Section 4: Processing: Matrices and Composites. Part 1 |
15 OCT 89 |
274 pages |
| Authors:
CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The third annual report of the University Research Initiative project at UCSB on High-Temperature, High-Performance Composites consists of sections compiled in a total of six books. The first section in Book 1 is concerned with the properties and structure of bimaterial interfaces and the related problem of coating decohesion and cracking. The second section describes research on the strengths and fracture resistance of brittle matrix composites manufactured with fibers, whiskers ... |
|
| The Processing and Mechanical Properties of High Temperature/High Performance Composites. Book 6, Section 4: Processing: Matrices and Composites. Part 2 |
15 OCT 89 |
249 pages |
| Authors:
CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The third annual report of the University Research Initiative project at UCSB on High-Temperature, High-Performance Composites consists of sections compiled in a total of six books. The first section in Book 1 is concerned with the properties and structure of bimaterial interfaces and the related problem of coating decohesion and cracking. The second section describes research on the strengths and fracture resistance of brittle matrix composites manufactured with fibers, whiskers ... |
|
| The High Temperature Alpha Field in the Titanium-Aluminum Phase Diagram |
89 |
|
| Authors:
C. McCullough; J. J. Valencia; H. Mateos; C. G. Levi; R. Mehrabian; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| An investigation was conducted to determine the reliability of the phase diagram of Ti-Al using high temperature x-ray diffraction of homogenized Ti-50at%Al and solidification experiments; these tests revealed that the phase in equlibrium with liquid Ti-50at%Al alloy is the hexagonal close packed solid solution based on alpha-Ti structure, and not the body centered cubic form represented on the current phase diagram which must be revised to include a high temperature ... |
|
| Solidification of Supercooled Intermetallic Powders |
89 |
|
| Authors:
C. G. Levi; J. J. Valencia; R. Mehrabian; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| Studies were made on the rapid liquid to solid transformations in intermetallic-forming Ti-Al powders at various levels of supercooling; A review of solidification both with and without equilibrium at the solid-liquid interface, thermal history of supercooled Ti-Al alloys, and experimental observations of Ti-(10-50) at% Al alloy powders, arc-melted buttons and splats were discussed; the solidification patterns have been described. |
|
| Microstructure Evolution in TiAl Alloys With B Additions: Conventional Solidification |
89 |
|
| Authors:
M. E. Hyman; C. McCullough; J. J. Valencia; C. G. Levi; R. Mehrabian; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| An investigation of the solidification microstructure of arc-melted, near-equiatomic TiAl alloys containing boron additions was performed, and the results were compared to solidification microstructures of binary Ti-Al and Ti-B alloys prepared similarly; the ternary alloy had a matrix consisting of the same alpha(sub 2) and gamma phases found in the binary TiAl with the exception of the boride phase; the boride phase was found to change; the solidification path has ... |
|
| The Strength and Fracture of Alumina Bonded With Aluminum Alloys |
89 |
|
| Authors:
B. J. Dalgleish; K. P. Trumble; A. G. Evans; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| Alumina has been liquid state bonded with pure al and al-4 wt% mg and the mechanical behavior of the bonds has been characterized. it has been shown that failure never occurs by interface cracking. instead, when the bond layer is thick, the bond strength is limited either by plastic flow or by ductile fracture in the metal. conversely, when the bond layer is thin, failure occurs in the ceramic, limited ... |
|
| The Structure of Delta-Alumina Evolved from the Melt and the Gamma Yields Delta Transformation |
89 |
|
| Authors:
V. Jayaram; C. G. Levi; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
|
| The Morphological Stability of Polycrystalline Fibers |
89 |
|
| Authors:
K. T. Miller; F. F. Lange; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
|
| Single Crystal Zirconia Thin Films from Liquid Precursors |
89 |
|
| Authors:
K. T. Miller; F. F. Lange; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
|
| Powder Processing and Densification of Ceramic Composites |
89 |
|
| Authors:
Fred F. Lange; David C. C. Lam; Olivier Sudre; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
|
| Densification Behavior of Al2O3 Powders Containing ZrO2 Inclusions |
89 |
|
| Authors:
O. Sudre; D. C. C. Lam; F. F. Lange; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
|
| The Effect of Interfaces on the Mechanical Performance of Fiber Reinforced Brittle Materials |
89 |
|
| Authors:
H. C. Cao; E. Bischoff; O. Sbaizero; M. Ruehle; A. G. Evans; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The mechanical properties of a series of six fiber-reinforced ceramics and glasses has been evaluated with the objective of critically assessing present understanding. A major parallel theme has been the characterization of the interface and an assessment of the thermomechanical properties of the interfaces as they relate to composite behavior. The results establish that the available mechanical property models correlate well with experiments, provided that independent measurements are made of ... |
|
| Debonding Properties of Residually Stressed Brittle-Matrix Composites |
89 |
|
| Authors:
P. G. Charalambides; A. G. Evans; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| Trends in interface debonding have been calculated during fiber pullout for composites with interfaces subject to residual tension. The debond behavior is shown to depend sensitively on the thermal expansion mismatch. The results are used as the basis for designing a pullout test specimen suitable for measuring the mixed-mode fracture energy of bimaterial interfaces. The solutions also provided the background needed to assess the role of debonding in the toughening ... |
|
| Fiber Debonding in Residually Stressed Brittle Matrix Composites |
89 |
|
| Authors:
P. G. Charalambides; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The competition between initial fiber debonding versus fiber failure marks a crucial event of the microstructural failure process in fiber reinforced brittle matrix composites. In this study, the role of a thermal residual stress field on the debonding conditions is examined theoretically and analytically. The analysis is based on two critical observations, the first being that the mechanics at the tip of a kink crack are driven only by the ... |
|
| Some Anisotropic Aspects and the Analysis of Mixed Mode Delamination Cracking in Fiber Reinforced and Laminated Ceramic Matrix Composites |
89 |
|
| Authors:
P. G. Charalambides; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The mechanics of delamination cracking for uniaxially fiber reinforced composites and laminated prenotched beams, for the combined loading of an applied moment and an axial force have been presented. As a first step, solutions for the delamination steady-state energy release rate (G) due to a moment were developed. It was demonstrated that G asymptotes to a universal value that depends only on the relative notch depth. Solutions for the delamination ... |
|
| Some Recent Developments in Numerical Modelling of Fracture Toughness in Brittle Matrix Composites |
89 |
|
| Authors:
C. L. Hom; P. A. Mataga; M; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| Finite element analysis was used to study the fracture toughening of a ceramic by a stress induced dilatant transformation of second phase particles. The finite element method was based on a continuum theory which modeled the composite as subcritical material. Transient crack growth was simulated in the finite element mesh by a nodal release technique. The crack's remote tensile opening load was adjusted to maintain the near tip energy release ... |
|
| Numerical Results for Transformation Toughening in Ceramics |
89 |
|
| Authors:
C. L. Hom; R. M. McMeeking; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| Finite element analysis was used to study the fracture toughening of a ceramic by a stress induced dilatant transformation of second phase particles. The finite element method was based on a continuum theory which modeled the composite as subcritical material. Transient crack growth was simulated in the finite element mesh by a nodal release technique. The crack's remote tensile opening load was adjusted to maintain the near tip energy release ... |
|
| Structure and Chemistry of Metal/Ceramic Interfaces. |
1989 |
|
| Authors:
M. Ruehle; A. G. Evans; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The present state of knowledge is reviewed concerning the structure and chemistry of metal/ceramic interfaces. experimental observations are described for several model systems and open problems concerning different aspects of structure and properties of heterophase boundaries are discussed. keywords:, mmc, review, survey, theoretical ag matrix, al2o3/nb, al2o3/pt, mgo/ag, nb matrix, pt matrix, adhesive work, diffusion bondings, internal oxidation, phase diagrams, edax, hrem, sem, tem, evaporations, thermal processing, atomistic models, bonding ... |
|
| A Method for Calculating Stress Intensities in Bimaterial Fracture. |
1989 |
|
| Authors:
P. P. L. Matos; R. M. McMeeking; P. G. Charalambrides; M. D. Drory; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| A numerical method is presented for obtaining the values of K(sub 1 asterisk), K(sub 2 asterisk), and K (sub 3 asterisk) in the elasticity solution at the tip of an interface crack in general states of stress. the basis of the method is an evaluation of the j-integral by the virtual crack extension method. individual stress intensities can then be obtained from further calculations of j perturbed by small increments ... |
|
| A Test Specimen for Determining the Fracture Resistance of Bimaterial Interfaces. |
1989 |
|
| Authors:
P. G. Charalambides; J. Lund; A. G. Evans; R. M. McMeeking; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, analytical, composite materials, experimental, mmc, theoretical materials and material types:, al/pmma, bimaterials, laminates, pmma/al material characteristics and data fields:, fracture resistances, poisson's ratios, strain energy release rates, strains, young's modulus testing and test conditions:, finite element methods, fracture analysis miscellaneous and special technical terms:, interfacial, models. |
|
| Effects of Non-Planarity on the Mixed Mode Fracture Resistance of Bimaterial Interfaces. |
1989 |
|
| Authors:
A. G. Evans; J. W. Hutchinson; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, analytical, composite materials, theoretical material characteristics and data fields:, compression, fracture resistances miscellaneous and special technical terms:, interfacial, mathematical, models. |
|
| The Morphological Stability of Polycrystalline Fibers. |
1989 |
|
| Authors:
K. T. Miller; F. F. Lange; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, cmc, composite materials materials and material types:, al2o3 layers, al2o3 substrates, fibers, laminates, polycrystalline fibers, substrates, zro2 fibers material characteristics and data fields:, grain boundary, grain growths manufacturing:, dry spinning, sintered, spinnings miscellaneous and special technical terms:, mathematical, morphology. |
|
| Toughening in Composites of Al2O3 Reinforced With Al. |
1989 |
|
| Authors:
B. D. Flinn; M. Ruehle; A. G. Evans; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, data, mmc, mmc data materials and material types:, al matrix, al2o3/al, in situ composites, toughened composites material characteristics and data fields:, plastic stretch data, strain data, toughening, work of rupture data testing and test conditions:, edax, tem miscellaneous and special technical terms:, darpa, in situ, mathematical, microstructures, n00014-86-k-0753 contracts, onr. |
|
| Partitioning Reactions to Control and Develop Unique Microstructures |
31 JUL 88 |
88 pages |
| Authors:
Fred F. Lange; Manfred Ruehle; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| TEM Transmission Electron Microscopy studies for different zirconium dioxide ceramics are reported. Observations are described to characterize the atomistic defects present in Mg-PSZ. TEM is applied to study phase stability and transformation in Y-TZP. The nucleation of stable m-ZrO2 at stress singularities associated with grain boundaries was studied in situ and related to strains and strain distributions determined by high resolution electron microscopy. The effect of grain growth on the ... |
|
| The Processing and Mechanical Properties of High Temperature/High Performance Composites. Book 6, Section 4: Processing: Intermetallics and Ceramic Composites |
88 |
|
| Authors:
A. G. Evans; R. Mehrabian; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The second annual report of the University Research Initiative project at UCSB on High-Temperature, High-Performance Composites consists of four sections compiled in a total of six books. The first section is concerned with the properties and structure of bimaterial interfaces and is expressed in Books 1 and 2. The second deals with the related problem of coating decohesion and cracking, Book 3. The third section describes research on the toughening ... |
|
| The Processing and Mechanical Properties of High Temperature/High Performance Composites. Book 4, Section 3: Toughening: Part 1 of 2 |
88 |
|
| Authors:
A. G. Evans; R. Mehrabian; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The second annual report of the University Research Initiative project at UCSB on High-Temperature, High-Performance Composites consists of four sections compiled in a total of six books. The first section is concerned with the properties and structure of bimaterial interfaces and is expressed in Books 1 and 2. The second deals with the related problem of coating decohesion and cracking, Book 3. The third section describes research on the toughening ... |
|
| The Processing and Mechanical Properties of High Temperature/High Performance Composites. Book 5, Section 3: Toughening: Part 2 of 2 |
88 |
|
| Authors:
A. G. Evans; R. Mehrabian; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The second annual report of the University Research Initiative project at UCSB on High-Temperature, High-Performance Composites consists of four sections compiled in a total of six books. The first section is concerned with the properties and structure of bimaterial interfaces and is expressed in Books 1 and 2. The second deals with the related problem of coating decohesion and cracking, Book 3. The third section describes research on the toughening ... |
|
| Toughening Mechanisms in Intermetallic Gamma-TiAl Alloys Containing Ductile Phases |
88 |
|
| Authors:
C. K. Elliott; G. R. Odette; G. E. Lucas; J. W. Sheckherd; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| Development towards better understanding of ductile phase toughening in powder-processed intermetallic gamma-tial alloys is the focus of this paper. the nominally ductile phases studied include nb and ti6al4v in the form of pancake-shaped particles. toughening is primarily due to the formation of crack face bridging zones. toughness increases in the composites with a ti6al4v phase are limited due to particle embrittlement during processing. in such a case, toughening is associated ... |
|
| Structure and Chemistry of Metal/Ceramic Interfaces |
88 |
|
| Authors:
M. Ruehle; A. G. Evans; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The present state of knowledge is reviewed concerning the structure and chemistry of metal/ceramic interfaces. also discussed are experimental observations described for several model systems as well as open problems concerning different aspects of structure and properties of heterophase boundaries. |
|
| The Influence of Residual Stress on the Toughness of Reinforced Brittle Materials |
88 |
|
| Authors:
D. B. Marshall; A. G. Evans; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
|
| High Toughness Ceramics |
88 |
|
| Authors:
A. G. Evans; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The principal microstructural sources of toughening are reviewed, with emphasis on comparisons between theory and experiment. Process zone mechanisms, such as transformation and microcracking, as well as bridging mechanisms induced by either ductile phases or fiber and whiskers are afforded primary consideration. Microstructural variable which allow toughness optimization are discussed. |
|
| Effects of Residual Stress and Frictional Sliding on Cracking and Pull- Out in Brittle Matrix Composites |
88 |
|
| Authors:
L. S. Sigl; A. G. Evans; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| The crack growth resistance and matrix cracking stress for high toughness brittle matrix composites depends on interface debonding, as well as the residual stress, the elastic properties, the friction coefficient along the debond and the fiber strength. A comprehensive analysis is prevented of the interrelationships between these variables for uniaxially reinforced systems when the interface is subject to residual compression. |
|
| The Strength of Ceramics Bonded With Metals. |
1988 |
|
| Authors:
B. J. Dalgleish; M. C. Lu; A. G. Evans; CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS
|
| This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, composite materials, experimental, mmc, theoretical materials and material types:, al2o3 materials, al2o3/au, al2o3/cu, al2o3/pt, layers, pt foils, pt layers material characteristics and data fields:, diffusion bondings, flow stress, interfacial failures, interfacial stresses testing and test conditions:, bending specimens, finite element methods, stress analysis miscellaneous and special technical terms:, interfacial, interfacial cracks, ... |
|
Reports by Corporate Author
