Ceramic materials are widely used as components in a great variety of applications. They are attractive due to their good high temperature strength, high wear resistance, good corrosion restistance and other special physical properties. Their major drawback is their brittleness and the large scatter of mechanical properties. This book describes failure phenomena in ceramic materials under mechanical loading, methods for determining the material properties, and the principles that one should apply when selecting a material. The fracture-mechanical and statistical principles and their use in describing the scatter of strength and lifetime are also covered. Special chapters are devoted to creep behaviour, multiaxial failure criteria and thermal shock behaviour.

Klappentext

The book gives a description of the failure phenomena of ceramic materials under mechanical loading, the methods to determine their properties, and the principles for material selection. The book presents fracture mechanical and statistical principles and their application to describe the scatter of strength and lifetime, while special chapters are devoted to creep behaviour, multiaxial failure criteria and thermal shock behaviour. XXXXXXX Neuer Text Describing how ceramic materials fracture and fail under mechanical loading, this book provides methods for determining the properties of ceramics, and gives criteria for selecting ceramic materials for particular applications. It also examines the fracture-mechanical and statistical principles and their use in understanding the strength and durability of ceramics. Special chapters are devoted to creep behavior, criteria for multiaxial failure, and behavior under thermal shock. Readers will gain insight into the design of reliable ceramic components.

Inhalt

1 Overview and Basic Properties.- 1.1 General Behaviour.- 1.2 Overview of Ceramic Materials.- 1.3 Fields of Application.- 2 Physical Properties.- 2.1 Thermal Expansion Coefficient.- 2.2 Thermal Conductivity.- 2.3 Electrical Conductivity.- 2.4 Specific Heat.- 2.5 Density.- 2.6 Elastic Constants.- 3 Fracture Mechanics.- 3.1 Fundamentals.- 3.1.1 Linear-Elastic Fracture Mechanics.- 3.1.2 Rising Crack Growth Resistance.- 3.2 Experimental Methods for the Determination of the Mode-I Fracture Toughness KIc.- 3.2.1 The Edge-Cracked Bending Bar.- 3.2.2 Specimens with Chevron Notches.- 3.2.3 Specimen with Knoop Indentation Crack.- 3.2.4 Vickers Indentation Cracks.- 3.2.5 Comparison of Different Specimen Types.- 3.3 Experimental Methods for the Determination of Mode-II and Mixed-Mode Fracture Toughness.- 3.3.1 Bending Test with Bars Containing Oblique Notches.- 3.3.2 Three-Point Bending Test with an Eccentric Notch.- 3.3.3 The Asymmetric Four-Point Bending Test.- 3.3.4 Diametral Compression Test.- 3.3.5 Surface Haws in Mixed-Mode Loading.- 3.4 Mixed-Mode Criteria and Experimental Results.- 4 R-Curve Behaviour.- 4.1 Experimental Observation.- 4.1.1 Results for Different Materials.- 4.1.2 Effect of Geometry and Loading Conditions.- 4.1.3 Work-of-Fracture.- 4.1.4 Comparison of Macro- and Microcracks.- 4.2 Determination of R-Curves.- 4.2.1 Specimens with Macrocracks.- 4.2.2 Specimens with Vickers Indentations.- 4.3 Reasons for R-Curve Behaviour.- 4.4 Influence of R-Curves on Strength.- 4.5 Computation of R-Curves.- 4.5.1 Fracture Mechanical Treatment of Bridging Stresses.- 4.5.2 Phase-Transformation Zone and Shielding Stress Intensity Factor.- 4.6 Determination of Bridging Stresses from Crack Profiles.- 5 Subcritical Crack Growth.- 5.1 Basic Relations.- 5.2 Computation of Lifetimes.- 5.2.1 Lifetimes Under Arbitrary Loading History.- 5.2.2 Lifetimes Under Static Load.- 5.2.3 Lifetimes Under Cyclic Load.- 5.3 Methods of Determining Subcritical Crack Growth.- 5.3.1 Double-Torsion Test.- 5.3.2 The Double-Cantilever-Beam Specimen.- 5.3.3 Crack Growth Data from Dynamic Bending Tests.- 5.3.4 Crack Growth Data from Static Bending Tests.- 5.3.5 Lifetime Prediction.- 5.4 Influence of R-Curve Behaviour on Subcritical Crack Growth.- 5.4.1 General Influence.- 5.4.2 Tests with Macroscopic Cracks.- 5.4.3 R-Curves for Subcritical Crack Extension.- 5.4.4 Lifetimes for Natural Cracks.- 5.5 Some Theoretical Considerations on Subcritical Crack Growth.- 6 Cyclic Fatigue.- 6.1 Representation of Cyclic Fatigue Results.- 6.2 Proof of a Cyclic Effect.- 6.3 Methods for the Determination of da/dN-?K Curves.- 6.4 Effect of R-Ratio.- 6.5 Theoretical Considerations.- 6.5.1 Effect of Crack Surface Interactions.- 6.5.2 Effect of Glass Phase Content.- 6.5.3 Effect of Phase Transformation Zones.- 6.6 Differences Between Micro- and Macrocracks.- 7 Determination of Strength.- 7.1 Measurement of Tensile Strength.- 7.1.1 The Tensile Test.- 7.1.2 The Bending Test.- 7.1.3 Test of Pipe Sections.- 7.2 Measurement of Compressive Strength.- 7.2.1 Compression Tests with Cylindrical Specimens.- 7.2.2 Compression Test on Hollow Cylinders.- 7.2.3 Results of Compression Tests.- 8 Scatter of Mechanical Properties.- 8.1 Principal Behaviour.- 8.2 Determination of Weibull Parameters.- 8.3 The Size Effect.- 8.4 Scatter of Lifetimes.- 8.5 Some Specific Problems.- 8.5.1 Three-Parameter Weibull Distribution.- 8.5.2 Multiple Flaw Population.- 8.5.3 Influence of the R-Curve.- 9 Proof Test Procedure.- 9.1 Proof Test Without Subcritical Crack Growth.- 9.2 Proof Test Including Subcritical Crack Growth.- 9.3 Problems in Proof Tests.- 9.3.1 Subcritical Crack Growth During the Proof Test.- 9.3.2 Different Flaw Population at High Temperatures.- 9.3.3 Simulation of the Service Conditions.- 10 Multiaxial Failure Criteria.- 10.1 Representation in Multiaxiality Diagrams.- 10.2 Global Multiaxiality Criteria.- 10.3 Defect Models.- 10.3.1 Cylindrical Pore.- 10.3.2 Spherical Pore.- 10.3.3 Ellipsoidal Pore.- 10.3.4 Circular Cracks.- 10.3.5 Conclusions from Defect Models.- 10.3.6 Statistical Treatment.- 10.3.7 Lifetime.- 10.4 Experimental Methods.- 10.4.1 The Ring-on-Ring Test.- 10.4.2 Ball-on-Ring Test.- 10.4.3 Brazilian-Disk Test.- 10.4.4 Tests with Tubes.- 10.4.5 Triaxial Stress States.- 10.5 Experimental Results.- 11 Thermal Shock Behaviour.- 11.1 Thermal Stresses.- 11.2 Measurement of Thermal Shock Sensitivity.- 11.3 Fracture Mechanical Treatment of Thermal Shock.- 11.4 Thermal Shock Parameters.- 11.5 Size Effect in Thermal Shock.- 11.6 Thermal Fatigue.- 12 High-Temperature Behaviour.- 12.1 Creep Deformation.- 12.1.1 Creep Relations for Tensile Tests.- 12.1.2 Differences in Tensile and Compression Creep.- 12.1.3 Creep Under Variable Stresses.- 12.1.4 Creep Under Bending Load.- 12.2 Failure in the Creep Range.- 12.2.1 Creep Fracture.- 12.2.2 Failure Maps.- 12.3 Creep Crack Growth.- 12.3.1 The C* Integral.- 12.3.2 Experimental Determination of C*.- 13 Plasticity.- 13.1 Plasticity During Contact Loading.- 13.2 Plasticity During Surface Grinding.- 13.3 Plasticity by Phase Transformation in Zirconia.- 13.4 Plasticity by Domain Switching in Piezoelectric Ceramics.- 13.5 Measurement of Plastic Deformations in Bending Tests.- 13.6 Time-Dependent Plasticity Effects.- A.1 Rectangular Bar.- A.2 Comact-Tension (CT) Specimen.- A.3 Round Compact Tension (RCT) Specimen.- A.4 Double-Cantilever-Beam Specimen (DCB).- A.5 Weight Function for Chevron-Notched Bending Bars.- A.6 Specimens for Mixed-Mode Tests.