Realizing that the properties of metals and alloys are determined by their microstructures and, in turn, that microstructure is controlled by thermal and mechanical processing, this seminar begins with a brief examination of the way in which metal atoms interact and bond to form a basic crystal structure. The casting and solidification of pure metals is examined briefly as a prelude to an explanation of the way in which alloys solidify. The concepts of solid solutions and phase diagrams are introduced in terms of common alloy systems such as steels and aluminum-base alloys. Thermal and mechanical processing methods for strengthening and toughening alloys are discussed, with special emphasis on the microstructure alterations that account for the changes in the properties of steels as a result of heat treatment. Precipitation hardening in alloys based on nonferrous metals (such as aluminum) is also explained.

After introducing the concepts and practices associated with control of microstructure, the relationships between microstructure and mechanical properties (hardness, strength, toughness, ductility, fatigue life, etc.) will be discussed and related to industrial practices for such processes as cold working, hardening and tempering of steels, and annealing. The methods used to test for mechanical properties will be reviewed and such terms as yield strength, tensile strength, fatigue limit, CVN toughness, and others will be explained.

This seminar will dispel some of the "witchcraft and black magic" often attributed to the practice of metallurgy. A better appreciation of the basics of the field will benefit those persons who find themselves involved in the specification and processing of metals as well as in quality control functions.

• Recognize and define key elements of terminology used in metallurgical practice
• Associate the control of the structure of metals and alloys with the properties that they exhibit
• Associate processing techniques with control of microstructure
• Describe and interpret the results of mechanical property testing of metals
  

• Brief Overview of the Field of Metallurgy and Materials
• Metals in the Solid State
  • Nature of crystals and the metallic bond between atoms
  • Effect of bonding on properties (elastic stiffness, thermal expansion, melting temperature)
  • Definition of crystal structures and their significance in metals and alloys
  • Important defects in metal crystals (vacancies, dislocations)
  • Grains and grain boundaries in metals
• Solidification of Pure Metals
  • As-cast structures (grain formation)
  • Casting defects (gas porosity, shrinkage cavities)
• Metal Alloys
  • Concept of solid state solubility
  • Phase diagrams
  • Development of microstructure during solidification
  • Equilibrium solidification
  • Inhomogeneous structures (coring) and alloy casting defects
  • Ferrous alloys
  • Nonferrous alloys
• Heat Treatment of Steel
  • Definition and designations for steels
  • The Fe-Fe3C phase diagram
  • Austenitizing
  • Influence of cooling rate on microstructure and hardness -- microstructures (pearlite, bainite, martensite); IT and CCT diagrams; annealing and normalizing; hardening by quenching and tempering; hardenability of steels (response to quenching); tempering quenched steels to improve ductility and toughness
  • Surface hardening by carburizing and induction
• Precipitation (Age) Hardening
  • Fundamentals
  • Age hardening of aluminum alloys
• Mechanical Properties of Metals and Alloys
  • Origin of mechanical properties in metal structures -- role of crystal defects (dislocations); role of microstructure
  • Definition and testing of mechanical properties (hardness, yield strength, tensile strength, ductility, toughness, fatigue life)
• Fabrication of Metals by Deformation Processing
  • Effects of cold working on structure and properties -- strain hardening; annealing to stress relieve and soften after cold work
  • Effects of hot working on structure and properties
  • General deformation methods (rolling, forging, drawing, etc.)
• Open Discussion of Issues Related to Metallurgy in the Transportation Vehicle Industry
• Summary and Wrap-up