18 Questions
What type of defect are dislocations classified as?
One-dimensional defects
When are dislocations typically introduced into the lattice of a material?
During solidification of the material
Which type of dislocation is formed by a shear stress applied to produce the distortion?
Pure screw dislocation
What is an edge dislocation characterized by?
An extra portion of a plane of atoms
Which type of dislocation exhibits components of both edge and screw dislocations?
Mixed dislocations
In which type of materials are dislocations particularly useful in explaining deformation and strengthening?
Metals only
What term is used to describe the dependence of physical properties on crystallographic direction?
Anisotropy
In which type of materials are the measured properties independent of the direction of measurement?
Isotropic materials
What increases with decreasing structural symmetry in materials?
Degree of anisotropy
What term describes a specimen composed of anisotropic grains behaving isotropically?
Homogeneous
Which property may have different values in different crystallographic directions?
Index of refraction
What is the term for the imperfections in atomic arrangements that affect the physical properties of materials?
Dislocations
What is the maximum allowable concentration of interstitial impurity atoms?
Less than 10%
Why must the atomic diameter of an interstitial impurity be substantially smaller than that of the host atoms?
To fit into the interstitial positions
What do surface defects do in a material?
Separate a material into regions with different orientations
What causes atomic mismatch at grain boundaries?
Transition in crystalline orientation from one grain to another
What defines a twin boundary in a material?
Specific mirror lattice symmetry
Why do small interstitial impurity atoms introduce lattice strains in a material?
Due to their larger size than interstitial sites
Test your knowledge about imperfections in atomic arrangements, focusing on dislocations which are linear or one-dimensional defects that result in misaligned atoms within a crystal lattice.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
