Test 2 Review
Crystallographic Defects
Grain
Grain Boundary
Interstitial defect
Point Defects
Small Angle Grain Boundary
Stacking Fault
Substitutional Defect
Surface Defects
Vacancy
Dislocations and slip
Dislocation density
Edge Dislocation
Mixed dislocation
Screw Dislocation
Slip
Slip Direction
Slip Plane
Slip System
Atomic Movement in Materials:
Activation Energy
Diffusion
Diffusion Coefficient
Flux
Grain Boundary Diffusion
Interstitial Diffusion
Self-Diffusion
Surface Diffusion
Vacancy Diffusion
Volume Diffusion
Chapter 6
Viscoelastic material
DBTT
Ductility
Elastic deformation
Engineering strain
Engineering stress
Flexural strength (MOR)
Fracture toughness
Hardness test
Impact energy
Impact test
Load
Macrohardness
Microhardness
Modulus of elasticity
Modulus of resilience
Necking
Offset yield strength
Percent elongation
Percent reduction in area
Plastic deformation
Poisson’s ratio
Stiffness
Strain
Strain gage
Strain rate
Stress relaxation
Tensile strength
True stress
True strain
Yield strength
Young’s modulus
Chapter 7
Climb
Creep
Endurance limit
Fatigue life
Fatigue strength
S-N curve
Stress corrosion
Striations
Toughness
Weibull modulus
Imperfections in the Atomic Arrangement and Slip
1. What do all lattice imperfections have in common?
2. In general, how are lattice imperfections and material properties related? How can
lattice imperfections be used to our benefit?
3. Show a simple schematic of a stress-strain curve (tensile). Identify the elastic vs
plastic regions.
4. What occurs to a crystal during elastic deformation?
5. What occurs to a crystal during plastic deformation?
6. How can the fact that the actual strength of a material is significantly lower than the
strength as predicted by the strength of the bonds?
7. Who is Goldie?
8. What is slip and how is it related to plastic deformation?
9. How can the movement of dislocations be impeded? What happens to the material
properties when this occurs?
10. How can the movement of dislocations be enhanced?
11. What is the critical resolved shear stress?
a. What law is used to describe this?
b. Name the three types of common crystal structures and identify the
relative critical resolved shear stress and explain why.
12. What is cross-slip? Which common crystal structures are capable of experiencing
cross-slip and why?
13. The relative strength and ductility of a material (crystal structure) depends ONLY on
the number of slip systems that that crystal structure has, right? Explain.
Atom Movement in Materials
1. What is diffusion?
2. What are the Arrhenius Plot and Arrhenius Equation?
3. What is the activation energy?
4. Draw a Vacancy.
5. Draw an Interstitial.
6. Name and describe the three major mechanisms of diffusion.
7. There are many factors that affect the rate of diffusion in materials.
7.1. List the factors.
7.2. Describe how these factors affect the rate of diffusion.
8. Name the types of diffusion and provide a schematic showing these.
9. Which type of diffusion provides for the fastest rate of diffusion and why?
10. Which type of diffusion provides for the slowest rate of diffusion and why?
11. Why is diffusion important for understanding material processing?
Chapter 6 and 7
1. Know how to generate a stress strain curve from load displacement data
2. Know the parts of a stress strain curve
3. Know how load and strain can be measured during testing
4. Understand the difference between macrohardness and microhardness testing
5. Know what an ASTM test standard is
6. Understand what impact testing is and the DBTT and how this relates to crystal
structures.
7. Understand the difference between:
a. Destructive and nondestructive testing
b. Structural and coupon testing
c. Field and laboratory testing
8. Understand some of the general concepts associated with the other tests discussed
briefly in class;
a. Creep
b. Fatigue
c. Bending
d. Fracture toughness
9. Understand how we use test data and why it is important to understand how the data
is generated.