Di Benedetto / Nicolais / Watanabe Composite Materials

1. Auflage 1992
ISBN: 978-0-444-60079-0
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 292 Seiten

The contributions in this volume bring together the experience of specialists on the highly complex technology required for manufacturing composite structural parts, presenting fundamental descriptions of the processing and properties of these advanced materials.The 34 papers give a thorough overview on recent advances in this field. The contributions have been collected in two general categories: composites based on organic matrices; and composites based on inorganic matrices. In each group properties and manufacturing technologies are analyzed together with long term durability and the special applications for such advanced materials.

Autoren/Hrsg.

Di Benedetto, A. T.

Nicolais, L.

Watanabe, R.

Inhaltsverzeichnis

1;Front Cover;1
2;Composite Materials;4
3;Copyright Page;5
4;Table Of Contents;10
5;Preface;6
6;Symposium Information;8
7;Part I: Composites with Organic Matrices;14
7.1;Chapter 1. Modelling of Processing Technologies for Polymer Matrix Composites;16
7.1.1;MODELLING PRINCIPLES FOR COMPOSITES PROCESSING;16
7.1.2;THERMOKINETIC MODEL;17
7.1.3;RHEOLOGICAL MODEL;18
7.1.4;HEAT TRANSFER;19
7.1.5;RESIN FLOW;21
7.1.6;VOID MODEL;21
7.1.7;CONCLUSIONS;23
7.1.8;REFERENCES;23
7.2;Chapter 2. Environmental Degradation of Polymeric Matrices for High Performance Composites;24
7.2.1;INTRODUCTION;24
7.2.2;PENETRANT SORPTION MODES;28
7.2.3;SORPTION EQUILIBRIA;29
7.2.4;POLYMER PENETRANT SENSITIVITY AND SORPTION HYSTERERIS;29
7.2.5;THE ORIGIN OF THE POLYMER MOISTURE SENSITIVITY;32
7.2.6;CONCLUSIONS;33
7.2.7;REFERENCES;34
7.3;Chapter 3. Recent Advances in Durability Analysis of Polymer Based Composite Systems;36
7.3.1;1. VISCOELASTICITY OF POLYMER BASED COMPOSITE SYSTEMS;37
7.3.2;2. DURABILITY ANALYSIS;38
7.3.3;3. LIMIT BEHAVIOUR;39
7.3.4;4. TIME-TEMPERATURE STRESS SUPERPOSITION PRINCIPLE (TTSSP);39
7.3.5;5. THE CRITICAL ELEMENT APPROACH;39
7.3.6;6. CONCLUSIONS;40
7.3.7;7. ACKNOWLEDGMENTS;40
7.3.8;8. REFERENCES;40
7.4;Chapter 4. Dielectric Characterization of Transport Phenomena in Composite Materials;42
7.4.1;INTRODUCTION;42
7.4.2;EXPERIMENTAL;43
7.4.3;RESULTS AND DISCUSSION;43
7.4.4;CONCLUSIONS;48
7.4.5;REFERENCES;48
7.5;Chapter 5. The Effect of Interfaces on Processing and Properties of Composite Materials;50
7.5.1;1. INTRODUCTION;50
7.5.2;2. WETTABILITY ISSUES IN PROCESSING;50
7.5.3;3. ANALYZING INTERFACES/INTERPHASES;53
7.5.4;4. USING INTERFACES/INTERPHASES TO ALTER MECHANICAL PROPERTIES;56
7.5.5;ACKNOWLEDGMENTS;58
7.5.6;REFERENCES;58
7.6;Chapter 6. Finite Element Analysis of the Effect of an Interphase on the Mechanical Properties of Polymeric Composite Materials– A Review;62
7.6.1;ABSTRACT;62
7.6.2;1. INTRODUCTION;62
7.6.3;2. FINITE ELEMENT METHOD F.E.M.;63
7.6.4;3. THE EFFECT OF AN INTERPHASE ON THE STRESS AND ENERGY DISTRIBUTION IN THE EMBEDDED SINGLE FIBER TEST;64
7.6.5;4. PARTICLE COMPOSITES: EFFECT OF AN INTERFACIAL LAYER ON COMPOSITE PROPERTIES;66
7.6.6;5. CONCLUSIONS;67
7.6.7;6. REFERENCES;67
7.7;Chapter 7. Determining the spatial distributions of fibres in composites;68
7.7.1;1. INTRODUCTION;68
7.7.2;2. RANDOM DISTRIBUTIONS - SIMULATIONS;69
7.7.3;3. SHORT FIBRE SPATIAL DISTRIBUTION;70
7.7.4;4. LONG FIBRE COMPOSITES;70
7.7.5;5. INTERPRETATION OF 2D STRUCTURE;72
7.7.6;6. ACKNOWLEDGEMENTS;73
7.7.7;7. REFERENCES;73
7.8;Chapter 8. Fiber Orientation in Short Fiber Injection-Moulded Thermoplastic Composites;74
7.8.1;1. INTRODUCTION;74
7.8.2;2. FIBER ORIENTATION MODELS;75
7.8.3;3. LEAL MODEL;75
7.8.4;4. MODIFIED LEAL MODEL FOR CURVILINEAR FLOW FIELDS;76
7.8.5;5. COMPARISON WITH THE EXPERIMENTAL RESULTS;77
7.8.6;6. FROZEN STRESSES DURING MOULD FILLING PHASE;79
7.8.7;7.REFERENCES;79
7.9;Chapter 9. Wear and Friction of Composite Materials;80
7.9.1;1. Introduction;80
7.9.2;2. Sliding Wear Testing Procedure;82
7.9.3;3. Wear Equations;82
7.9.4;4. Sliding Wear of Polymers and Their Short Fiber Reinforced Composites;84
7.9.5;5. Conclusions;96
7.9.6;Acknowledgements;96
7.9.7;References;97
7.10;Chapter 10. Study on the Effect of Abrasives in Friction Materials Composites;100
7.10.1;1. INTRODUCTION;100
7.10.2;2. EXPERIMENTAL;101
7.10.3;3. RESULTS;101
7.10.4;4. DISCUSSION AND CONCLUSIONS;105
7.10.5;5. ACKNOWLEDGEMENT;106
7.10.6;6. REFERENCES;106
7.11;Chapter 11. Tribological tests with filled plastics;108
7.11.1;1. INTRODUCTION;108
7.11.2;2. EXPERIMENTAL PROCEDURE;109
7.11.3;3. EXPERIMENTAL RESULTS;109
7.11.4;4. DISCUSSION;111
7.11.5;5. CONCLUSIONS;113
7.11.6;6. ACKNOWLEDGEMENT;113
7.11.7;7. REFERENCES;113
7.12;Chapter 12. Polymeric Adhesives: Optimization of Inductive Heating System for Exterior Body Panels;114
7.12.1;1. INTRODUCTION;114
7.12.2;2. DESCRIPTION OF EQUIPMENT AND SPECIMEN;114
7.12.3;3. CHOICE OF PLAN OF EXPERIMENTS;115
7.12.4;4 . DEFINITION OF THE QUALITY CHARACTERISTIC;115
7.12.5;5. ANALYSIS OF RESULTS;116
7.12.6;6. CONCLUSIONS;117
7.12.7;ACKNOWLEDGEMENT;117
7.12.8;REFERENCES;117
7.12.9;BIOGRAPHIES;117
7.13;Chapter 13. Characterization of the Ablative Behaviour of Composite Materials;120
7.13.1;INTRODUCTION;120
7.13.2;COMPOSITE MATERIALS AS THERMAL PROTECTION SYSTEMS;121
7.13.3;MODELLING O F THE ABLATION PROCESS;124
7.13.4;THERMOGRAVIMETRIC ANALYSIS OF THE DECOMPOSITION KINETICS;125
7.13.5;CONCLUSIONS;127
7.13.6;REFERENCES;127
7.14;Chapter 14. Viscoelastic properties of composites;128
7.14.1;1. INTRODUCTION;128
7.14.2;2. MATERIALS AND METHODS;129
7.14.3;3. ANELASTIC LOSSES AROUND THE GLASS TRANSITION TEMPERATURE;132
7.14.4;4. ANELASTIC LOSSES BELOW THE GLASS TRANSITION TEMPERATURE;135
7.14.5;5. CONCLUSION;138
7.14.6;6. REFERENCES;138
7.15;Chapter 15. The influence of temperature on the strength and creep behaviour of carbon-fibre reinforced thermoplastics;140
7.15.1;1. INTRODUCTION;140
7.15.2;2. TEST METHODS;140
7.15.3;3. MATERIALS;141
7.15.4;4. RESULTS;141
7.15.5;5. DISCUSSION AND CONCLUSIONS;144
7.16;Chapter 16. Creep Damage and Rupture in Carbon/PEEK Composite;146
7.16.1;1 . INTRODUCTION;146
7.16.2;2. MATERIAL AND EXPERIMENTAL TECHNIQUES;147
7.16.3;3. RESULTS AN DISCUSSION;147
7.16.4;4. CONCLUSION;151
7.16.5;5. REFERENCES;152
7.17;Chapter 17. Novel TPO Based Magnetic Composites;154
7.17.1;1. INTRODUCTION;154
7.17.2;2. EXPERIMENTAL;155
7.17.3;3. RESULTS AND DISCUSSION;159
7.17.4;4. ACKNOWLEDGEMENTS;159
7.17.5;5. REFERENCES;159
7.18;Chapter 18. Numerical Analysis of Buckling Response For Some Axially Loaded Cylindrical CFRP Panels;160
7.18.1;1 INTRODUCTION;160
7.18.2;2 PROBLEM FORMULATION;161
7.18.3;3 ISOTROPIC MATERIAL;162
7.18.4;4 COMPARISONS WITH THEORETICAL FORMULATION;163
7.18.5;5 ORTHOTROPIC MATERIALS;163
7.18.6;REFERENCES;166
8;Part II: Composites with Inorganic Matrices;168
8.1;Chapter 19. SiC Whisker Reinforced Alumina Matrix Composites;170
8.1.1;ABSTRACT;170
8.1.2;1. Introduction;170
8.1.3;2. Toughening mechanisms in composites.;171
8.1.4;3. Factors affecting toughening by whiskers;178
8.1.5;4. Conclusion;183
8.1.6;References;184
8.2;Chapter 20. Importance of Interfaces in Aluminium and Magnesium Alloy Metal Matrix Composites Reinforced with SiC Particles;186
8.2.1;ABSTRACT;186
8.2.2;INTRODUCTION;186
8.2.3;ZCM 630 Alloy;189
8.2.4;Conclusions;191
8.2.5;Acknowledements;191
8.2.6;References;191
8.3;Chapter 21. SiC-Si3N4 CVD composite layer;192
8.3.1;1. INTRODUCTION;192
8.3.2;2. EXPERIMENTAL;193
8.3.3;3. RESULTS AND DISCUSSION;193
8.3.4;4. SUMMARY;195
8.3.5;5. REFERENCES;196
8.4;Chapter 22. Laser Synthesis of Composite Si/C/N Ceramic Powders;198
8.4.1;1. INTRODUCTION;198
8.4.2;2. EXPERIMENTAL;199
8.4.3;ACKNOWLEDGEMENT;203
8.4.4;3. REFERENCES;203
8.5;Chapter 23. Vibrational properties of piezoelectric composites;204
8.5.1;1. INTRODUCTION;204
8.5.2;2. EXPERIMENT;205
8.5.3;3. RESULTS AND DISCUSSION;205
8.5.4;4. REFERENCES;209
8.6;Chapter 24. Recent Development of Functionally Gradient Materials For Special Application to Space Plane.;210
8.6.1;ABSTRACT;210
8.6.2;1. INTRODUCTION;210
8.6.3;2. P/M FABRICATION PROCEDURES OF FGM;212
8.6.4;3. OPTIMUM COMPOSITION PROFILE DESIGN;214
8.6.5;4. THERMOMECHANICAL EVALUATION OF P/M FGM;216
8.6.6;5. MICROSTRUCTURAL OPTIMIZATION;218
8.6.7;6. CONCLUDING REMARKS;219
8.6.8;ACKNOWLEDGEMENTS;220
8.6.9;REFERENCES;220
8.7;Chapter 25. Ceramic matrix nanocomposites;222
8.7.1;1. INTRODUCTION;222
8.7.2;2. EXPERIMENTAL;222
8.7.3;3. RESULTS;223
8.7.4;4. DISCUSSION;226
8.7.5;5. CONCLUSIONS;227
8.7.6;6. REFERENCES;227
8.8;Chapter 26. Matrix vs Interface Contribution in Al/SiC MMC'S;228
8.8.1;1. INTRODUCTION;228
8.8.2;2. SPECIMEN PREPARATION;230
8.8.3;3. RESULTS;231
8.8.4;4. DISCUSSION;232
8.8.5;5. CONCLUSION;232
8.8.6;6. ACKNOWLEDGEMENTS;233
8.8.7;7. REFERENCES;233
8.9;Chapter 27. Wetting and reactivity of SiC particulates with liquid aluminium alloys;234
8.9.1;1. INTRODUCTION;234
8.9.2;2. MATERIALS AND EXPERIMENTAL PROCEDURES;235
8.9.3;3. RESULTS AND DISCUSSION;236
8.9.4;4. CONCLUDING REMARKS AND FUTURE WORK;239
8.9.5;ACKNOWLEDGEMENTS;239
8.9.6;REFERENCES;239
8.10;Chapter 28. X–RAY LINE BROADENING FOURIER ANALYSIS OF A METAL MATRIX COMPOSITE OBTAINED BY LIQUID INFILTRATION AFTER SLOW AND RAPID COOLING FROM HIGH ANNEALING TEMPERATURE;240
8.10.1;1. INTRODUCTION;240
8.10.2;2. EXPERIMENTAL;241
8.10.3;3. RESULTS AND DISCUSSION;241
8.10.4;4. CONCLUSIONS;245
8.10.5;ACKNOWELEDGMENTS;245
8.10.6;5.REFERENCES;245
8.11;Chapter 29. Simulation of the behaviour of high temperature oxidized structures (application to coating);246
8.11.1;1. INTRODUCTION;246
8.11.2;2. MECHANICAL MODEL;247
8.11.3;3. NUMERICAL MODEL;249
8.11.4;4. EXAMPLE AND RESULTS;249
8.11.5;5. COMPARISON CALCULATION / EXPERIENCE;250
8.11.6;6. CONCLUSION;250
8.11.7;REFERENCES;251
8.12;Chapter 30. NiAl–TiB2 Composite Manufactured by Melt Spinning;252
8.12.1;1. INTRODUCTION;252
8.12.2;2. EXPERIMENTAL PROCEDURES;253
8.12.3;3. RESULTS AND DISCUSSION;253
8.12.4;4. CONCLUSIONS;257
8.12.5;ACKNOWLEDGEMENTS;257
8.12.6;5. REFERENCES;257
8.13;Chapter 31. Liquid phase sintering of stainless steel matrix composites;258
8.13.1;1. INTRODUCTION;258
8.13.2;2. EXPERIMENTAL PROCEDURE;259
8.13.3;3. RESULTS AND DISCUSSION;259
8.13.4;4. CONCLUSION;262
8.13.5;5. REFERENCES;263
8.14;Chapter 32. Aluminide oxidation barrier on nickel–cobalt / ThO2 composites obtained by a pack diffusion type coating process;264
8.14.1;1. INTRODUCTION;264
8.14.2;2. EXPERIMENTAL;265
8.14.3;3. RESULTS;266
8.14.4;4. CONCLUSIONS;268
8.14.5;ACKNOWLEDGMENTS;270
8.14.6;5. REFERENCES;270
8.15;Chapter 33. Manufacture and characterization of continuous SiC fibre reinforced aluminium composites by low pressure plasma spraying;272
8.15.1;Abstract;272
8.15.2;Introduction;272
8.15.3;I. Experimental;273
8.15.4;II. Results and discussion;275
8.15.5;Conclusions;283
8.15.6;References;283
8.16;Chapter 34. Thermal characterization of multilayer structures of cera mic ferrites;286
8.16.1;1 - INTRODUCTION;286
8.16.2;2- SAMPLE PREPARATION;287
8.16.3;3- THERMAL DIFFUSIVITY MEASUREMENTS;288
8.16.4;4- LAYERED STRUCTURE;290
8.16.5;5- CONCLUSIONS;291
8.16.6;6- REFERENCES;291
9;AUTHOR INDEX;292

Leseproben

Modelling of Processing Technologies for Polymer Matrix Composites

Jose M. Kenny    Department of Materials and Production Engineering, University of Naples, P. Tecchio, 80125, Naples, ITALY

Abstract

A general model for the description of the thermo-chemo-rheological changes of the matrix during the processing of polymer based composites, has been developed in recent years. The master model includes, specific submodels dedicated to the different physico-chemical aspects of composite processing: reaction kinetics, heat transfer, viscosity, fluid flow and void formation during processing. The main objective of this work is to highlight the contribution of the understanding of the matrix behaviour to the right choice of processing conditions.

MODELLING PRINCIPLES FOR COMPOSITES PROCESSING

In the last decade several studies of the fundamental aspects of the processing of high performance composites have been reported [1–6]. In those research works a common scientific approach based on the understanding of the fundamental chemical and physical phenomena governing the behaviour of the composite matrix and allowing a better choice and control of processing conditions has been developed.

The final objective of those activities was the construction of a general processing model that could be adapted to different specific technologies. In order to develop such general model several submodels are needed as shown in Fig. 1. The first submodel describes the kinetics of the matrix chemical transformations, responsible of the final structure of the composite. The thermokinetic model predicts the exothermal heat of reaction and the degree of cure as a function of process time and temperature. The rheological model describes the viscosity evolution as function of time, temperature and degree of cure. Therefore, the rheological model is combined with the thermokinetic model forming the chemorheological model including also the gel point. For non-isothermal conditions also a heat transfer model is needed. If the heat transfer model is combined with the chemorheological and cure kinetic models, the degree of cure, temperature and viscosity, as a function of time and position in the composite, can be predicted. The flow model predicts resin content distribution and final composite thickness. Finally, the void model predicts the conditions needed to avoid the formation of voids.

Figure 1 Modeling philosophy of the processing of composite materials

A more detailed examination of the modelling of composite processing technologies will be given in the following sections where each of the submodels mentioned in this section, integrated into a general master model, will be discussed.

THERMOKINETIC MODEL

The thermokinetic model is the first step in the construction of the master model being a prerequisite for all the other submodels. It describes the rate at which heat is given off during the reaction, and the degree of cure, a, as a function of temperature and time. For curing reactions, the rate of heat flow dH/dt, can be conveniently measured by differential scanning calorimetry (DSC) [7]. It has been assumed for these processes that the quantity dH/dt is directly proportional to the rate of disappearance of reactive groups during curing, da/dt. Empirical thermokinetic models for non-autocatalytic reactions have usually the following form:

a/dt=K1-an

  (1)

Integration of this equation can be used to predict a, da/dt and dH/dt as a function of time and temperature. The rate constant K depends on temperature and generally is given by:

=KOexp–E/RT

  (2)

KO is a preexponencial factor (frequency factor), E is the activation energy, R is me gas constant and T the absolute temperature. A much better description of the thermoset behavior has recently been reported [8]:

a/dt=Aexp–E/RTam–an

  (3)

where am is the maximum degree of reaction obtained at a given temperature in an isothermal test. For reactions with autocatalytic behavior the following rate equation has been found useful [9]:

a/dt=K1+K2am1–an

  (4)

where K1 and K2 are the kinetic constants depending on the temperature through an Arrhenius type equation like Eq. (2).

Although there are several ways to determine the parameters of the kinetic equation [7], one procedure is to perform isothermal DSC tests and then use nonlinear regression analysis to determine the constants [8]. The model can then be verified by comparison with results obtained in isothermal and in dynamic tests performed at different heating rates.

A practical application of the thermokinetic model is the prediction of the cure time at a given temperature to reach a specified degree of cure, for example the end of the cure or the gel point in combination with viscosity measurements. The thermokinetic model can be also used associated with the chemorheological model to describe the evolution of the polymeric structure and its viscosity. Finally, the thermokinetic model also predicts the amount of heat given off during the reaction. Then, if it is coupled with a heat transfer model (as described later), the temperature and degree of cure distribution inside a composite can be described for non-isothermal conditions.

RHEOLOGICAL MODEL

The rheological model should be able to predict the viscosity as a function of temperature and time. Since the viscosity depends on the degree of cure, the viscosity model has to be combined with the thermokinetic model, in the chemorheological model.

Viscosity measurements are usually performed in a dynamic mechanic spectrometer for fluids provided with disposable parallel plates. The location of the gel point can be determined from infinite viscosities obtained in shear mode tests [10]. Also it has been determined as the minimum in the loss factor (tan delta) at low frequencies [6] in dynamic tests.

There are two different phenomena which govern the viscosity of a thermoset [10]. One phenomenon is the growing size of the molecules during curing which increases the viscosity of the resin. The other is the effect of temperature on molecular mobility. These two mechanisms together determine the viscosity of reactive polymers in the fluid state. A fundamental approach has been reported [5,10]. The temperature effect can be taken into account using the WLF-equation while the molecular size dependence is considered a function of the molecular weight (Mw). Following this approach the final expression of the viscosity becomes:

aT/µo=gMwa/Mwo)3.4expC1Tr-Tgo/C2+Tr-TgoexpC1T-Tga/C2+T-Tga

  (5)

The parameter g is the ratio of the square of the radii of gyration of a branched to a linear chain of the same molecular weight; g is a number on the order of 1 that can be calculated applying statistical analysis. Since Tg depends on the degree of cure this dependence has to be determined and included into the expression. Equation (6) was found to successfully describe the experimentally determined viscosity of a model TGDDM-DDS epoxy system [10] and of TGDDM-DDS matrices of commercial prepregs [5]. The described theoretical approach, based on fundamental physical and chemical principles, requires the knowledge of the molecular weight and of the functionalities of the components, the nature of the chemical reactions and how Tg varies with the degree of cure.

For thermosets with complicated reaction mechanisms or where the composition and functionalities of the molecules in the resin mixture are unknown, an empirical approach is necessary. In order to describe the viscosity of polyester matrices Kenny et al. [6] adopted a model similar to the one originally used by Castro and Macosko for polyurethanes viscosity [11]:

=AµexpEµ/RTag/ag-aA+Ba

  (6)

where µ is the viscosity, ag is the extent of reaction at the gel point and Aµ, Eµ, A and B are constants to be determined by regression analysis of experimental data.

In addition to the prediction of minimum viscosity and gelation, one important application of chemorheological models is the ability to design resin chemistry and processing conditions in order to obtain specific viscosity characteristics. As an example, too low resin viscosity during autoclave curing of carbon fiber/epoxy may cause starvation problems. On the other hand, if the resin viscosity is too high, consolidation problems may arise. Then, the cured composite may contain voids and other defects. Therefore, a processing window in terms of required viscosities must be defined in order to produce a composite with the required resin content.

HEAT TRANSFER

As discussed earlier, the cure of a thermoset is always associated with a significant development of heat. The temperature distribution inside the composite will depend on the competition between heat generation and heat diffusion through the thickness. While for thin laminates it can be assumed that the...