Gamma Titanium Aluminide Alloys

Preface
 
INTRODUCTION
 
CONSTITUTION
The Binary Ti-Al Phase Diagram
Ternary and Multicomponent Alloy Systems
 
THERMOPHYSICAL CONSTANTS
Elastic and Thermal Properties
Point Defects
Diffusion
 
PHASE TRANSFORMATIONS AND MICROSTRUCTURES
Microstructure Formation on Solidification
Solid State Transformations
 
DEFORMATION BEHAVIOR OF SINGLE-PHASE ALLOYS
Single-Phase Gamma(TiAl) Alloys
Deformation Behavior of Single-Phase Alpha2(Ti3Al) Alloys
Beta/B2 Phase Alloys
 
DEFORMATION BEHAVIOR OF TWO-PHASE ALPHA(Ti3Al) + GAMMA(TiAl) ALLOYS
Lamellar Microstructures
Deformation Mechanisms, Contrasting Single-Phase and Two-Phase Alloys
Generation of Dislocations and Mechanical Twins
Glide Resistance and Dislocation Mobility
Thermal and Athermal Stresses
 
STRENGTHENING MECHANISMS
Grain Refinement
Work Hardening
Solution Hardening
Precipitation Hardening
Optimized Nb-Bearing Alloys
 
DEFORMATION BEHAVIOR OF ALLOYS WITH A MODULATED MICROSTRUCTURE
Modulated Microstructures
Misfitting Interfaces
Mechanical Properties
 
CREEP
Design Margins and Failure Mechanisms
General Creep Behavior
The Steady-State or Minimum Creep Rate
Effect of Microstructure
Primary Creep
Creep-Induced Degradation of Lamellar Structures
Precipitation Effects Associated with the Alpha2 -> Gamma Phase Transformations
Tertiary Creep
Optimized Alloys, Effect of Alloy Composition and Processing
Creep Properties of Alloys with a Modulated Microstructure
 
FRACTURE BEHAVIOR
Length Scales in the Fracture of TiAl Alloys
Cleavage Fracture
Crack-Tip Plasticity
Fracture Toughness, Strength, and Ductility
Fracture Behavior of Modulated Alloys
Requirements for Ductility and Toughness
Assessment of Property Variability
 
FATIGUE
Definitions
The Stress-Life (S-N) Behavior
HCF
Effects of Temperature and Environment on the Cyclic Crack-Growth Resistance
LCF
Thermomechanical Fatigue and Creep

Fritz Appel has continued to play an active role in TiAl research since his retirement in 2006 as group leader of physical metallurgy. He obtained his Ph.D. in 1973 and his habilitation in 1987 from the Martin-Luther University in Halle, Germany. He spent six months in Japan on a JSPS fellowship in 1987, joining the GKSS Research Center in Geesthacht in 1990. Dr. Appel received the Tammann Award from the German Society for Materials Science in 1999 and the Charles Hatchett Award in 2002 from the Institute of Materials, London. He has published over 160 papers, given over 80 invited lectures and holds six patents in the field.

Jonathan Paul has been a member of the Institute of Materials Research in Geesthacht since 1999. He obtained his Ph.D. from Manchester University in 1990, and after a year of postdoctoral research, moved to the Commissariat à l'Énergie Atomique at Saclay in 1993. Between 1995 and 1997 he worked as a research fellow at GKSS, before being employed at the Defence Evaluation Research Agency (formerly known as the Royal Aircraft Establishment, now re-named QinetiQ) within the Structural Materials Centre in Farnborough. Dr. Paul received the Vanadium Award in 1995 and the Charles Hatchett Award in 2002, both from the Institute of Materials, London. He has co-authored and authored a number of publications and holds four patents.

Michael Oehring works in the physical metallurgy group at the Institute of Materials Research in Geesthacht. He received his Ph.D. in 1988 from the University of Göttingen, Germany, where he remained until 1989, working in the area of field ion microscopy. He then joined the applied physical metallurgy group at GKSS, where he remained until 1993, before transferring to the group headed by Fritz Appel. Dr. Oehring received the Charles Hatchett Award in 2002 from the Institute of Materials, London, and has authored or co-authored over 100 papers as well as five patents.a research fellow at GKSS, before being employed at

The authors probably had the intention to create a guide through the issue of TiAl-alloys, what they have succeeded. All in all, the book is everything but boring. It makes curious while reading and explains simply and in detail the materials technology of TiAl-alloys. To summarize, this book is not only useful as a reference book for industrial users, but also as a textbook for students. It should really not be
missing in any university library.