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What is a dislocation in the context of materials science?
What is a dislocation in the context of materials science?
When was the existence of dislocations directly observed?
When was the existence of dislocations directly observed?
What are the two primary types of dislocations?
What are the two primary types of dislocations?
Which of the following best describes an edge dislocation?
Which of the following best describes an edge dislocation?
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What is the motion of a screw dislocation?
What is the motion of a screw dislocation?
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What is the term used to describe permanent deformation of materials by dislocation motion?
What is the term used to describe permanent deformation of materials by dislocation motion?
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Which of the following is true about a slip system?
Which of the following is true about a slip system?
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What is a slip plane?
What is a slip plane?
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What is slip direction?
What is slip direction?
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What does grain size reduction do to a material's strength?
What does grain size reduction do to a material's strength?
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According to the Hall-Petch Equation, what happens as grain size decreases?
According to the Hall-Petch Equation, what happens as grain size decreases?
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Which of the following strengthening mechanisms involves adding alloying elements to a metal?
Which of the following strengthening mechanisms involves adding alloying elements to a metal?
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What type of impurity atom replaces a host atom in solid solution strengthening?
What type of impurity atom replaces a host atom in solid solution strengthening?
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What type of impurity atoms fill the gaps between atoms in solid solution strengthening?
What type of impurity atoms fill the gaps between atoms in solid solution strengthening?
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Which strengthening mechanism involves the metal becoming stronger after plastic deformation?
Which strengthening mechanism involves the metal becoming stronger after plastic deformation?
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What is the effect of strain hardening on a metal?
What is the effect of strain hardening on a metal?
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What is percent cold work (PCW) a measure of?
What is percent cold work (PCW) a measure of?
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Which of the following is the formula for percent cold work?
Which of the following is the formula for percent cold work?
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What is recovery in the context of metal deformation?
What is recovery in the context of metal deformation?
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What occurs during recrystallization?
What occurs during recrystallization?
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What happens during grain growth?
What happens during grain growth?
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What is the primary role of grain boundaries in strengthening metals?
What is the primary role of grain boundaries in strengthening metals?
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Which technique is most effective for strengthening polycrystalline materials?
Which technique is most effective for strengthening polycrystalline materials?
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What happens when metals undergo extensive plastic deformation at low temperatures?
What happens when metals undergo extensive plastic deformation at low temperatures?
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Which of the following is NOT a stage in the recovery, recrystallization, and grain growth process?
Which of the following is NOT a stage in the recovery, recrystallization, and grain growth process?
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What are polymers?
What are polymers?
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What are the repeating units in polymers called?
What are the repeating units in polymers called?
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Which of the following is a natural polymer?
Which of the following is a natural polymer?
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Which polymer is used to make plastic bags?
Which polymer is used to make plastic bags?
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Which polymer is known for its elasticity?
Which polymer is known for its elasticity?
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Which polymer is commonly used to make pipes?
Which polymer is commonly used to make pipes?
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Which polymer is lightweight, strong, and used in packaging?
Which polymer is lightweight, strong, and used in packaging?
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Which of the following is a synthetic polymer?
Which of the following is a synthetic polymer?
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What is the main monomer used to make polystyrene?
What is the main monomer used to make polystyrene?
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What is cross-linking in polymers?
What is cross-linking in polymers?
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What is the main feature of biodegradable polymers?
What is the main feature of biodegradable polymers?
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Which polymer is used for making bottles?
Which polymer is used for making bottles?
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What is Bakelite used for?
What is Bakelite used for?
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What is the process called when monomers join without producing any byproduct?
What is the process called when monomers join without producing any byproduct?
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What property allows polymers to stretch and return to their original shape?
What property allows polymers to stretch and return to their original shape?
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Which polymer is used for making bulletproof vests?
Which polymer is used for making bulletproof vests?
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What property of polymers makes them suitable for use as insulators in electrical applications?
What property of polymers makes them suitable for use as insulators in electrical applications?
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What is a key factor affecting the strength of a polymer?
What is a key factor affecting the strength of a polymer?
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Which property of polymers is enhanced by cross-linking?
Which property of polymers is enhanced by cross-linking?
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Why are polymers like polystyrene used for insulation?
Why are polymers like polystyrene used for insulation?
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What does the molecular mass of a polymer represent?
What does the molecular mass of a polymer represent?
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Which term is used to describe the average molecular mass of polymers weighted by the number of molecules?
Which term is used to describe the average molecular mass of polymers weighted by the number of molecules?
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The Polydispersity index (PDI) is calculated using which formula?
The Polydispersity index (PDI) is calculated using which formula?
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What is the value of the Polydispersity index (PDI) of natural polymers?
What is the value of the Polydispersity index (PDI) of natural polymers?
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Which of the following accurately describes weight-average molecular mass (MW)?
Which of the following accurately describes weight-average molecular mass (MW)?
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Why is it important to study failure?
Why is it important to study failure?
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What is one of the three usual causes of failure?
What is one of the three usual causes of failure?
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Which type of fracture is usually preferred?
Which type of fracture is usually preferred?
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Why is ductile fracture preferred over brittle fracture?
Why is ductile fracture preferred over brittle fracture?
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Which type of environment-assisted fatigue failure involves fluctuating thermal stresses?
Which type of environment-assisted fatigue failure involves fluctuating thermal stresses?
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What are the three usual causes of failure?
What are the three usual causes of failure?
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Which type of fracture occurs with very little accompanying plastic deformation?
Which type of fracture occurs with very little accompanying plastic deformation?
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What is the main characteristic of brittle fracture?
What is the main characteristic of brittle fracture?
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What type of failure is the single largest cause of failure in metals?
What type of failure is the single largest cause of failure in metals?
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Which testing techniques are used to measure impact energy?
Which testing techniques are used to measure impact energy?
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What is fatigue?
What is fatigue?
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What is the definition of creep?
What is the definition of creep?
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Which phase of creep involves a constant creep rate?
Which phase of creep involves a constant creep rate?
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What type of creep occurs at elevated temperatures due to fluctuating stresses?
What type of creep occurs at elevated temperatures due to fluctuating stresses?
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Which type of crack is more stable, requiring an increase in applied stress to propagate?
Which type of crack is more stable, requiring an increase in applied stress to propagate?
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Study Notes
Materials Science - Dislocations and Strengthening Mechanisms
- Dislocation Definition: A linear crystalline defect in the atomic structure.
- Dislocation Observation: Dislocations were directly observed in the 1950s.
- Primary Dislocation Types: Edge and screw.
- Edge Dislocation Description: An extra half-plane of atoms is inserted.
- Screw Dislocation Motion: The dislocation moves perpendicular to the applied stress.
- Permanent Deformation Term: Slip.
- Slip System: Involves the movement of dislocations along a slip plane and direction.
- Slip System Criterion: Only occurs in materials with cubic crystal structures.
Materials Science - Slip System and Planar Attributes
- Slip Plane: The plane with the highest density of atoms.
- Slip Direction: The direction in which dislocations move within the slip plane.
Materials Science - Grain Size and Strength
- Grain Size Reduction Effect: Increases strength by increasing grain boundaries.
Materials Science - Strengthening Mechanisms
- Solid Solution Strengthening: Adding alloying elements.
- Grain Size Reduction Strengthening: Decreases strength by reducing dislocation movement but increases strength by increasing grain boundaries.
- Strain Hardening: Strengthening a metal after plastic deformation.
Materials Science - Recovery, Recrystallization, and Grain Growth
- Recovery Process: Mild heating to rearrange dislocations without affecting hardness.
- Recrystallization: New, strain-free grains form, reducing dislocation density.
- Grain Growth: Grains grow larger and the number of grain boundaries decreases and strength reduces.
Materials Science - Failure
- Causes of Failure: Improper material selection, processing, and design.
- Types of Failure: Fracture, fatigue, and creep.
- Ductile Fracture: Provides a warning before failure, less energy intensive.
- Brittle Fracture: Occurs with no prior deformation.
- Fatigue: Failure that results from repeated stress or strain cycling.
- Creep: Time-dependent and permanent deformation of materials subjected to constant stress or load.
Materials Science - Polymer Basics
- Polymers Definition: Large molecules composed of repeating units.
- Repeating Units: Monomers
- Natural Polymer Example: Rubber.
- Synthetic Polymer Example: Teflon
Materials Science - Polymer Properties and Applications
- Elasticity Polymer Example: Rubber
- Plastic Bag Polymer: Polyethylene
- Bulletproof Vest Polymer: Kevlar
- Insulating Polymer: Certain types of polymers.
- Polystyrene Use: Insulation
- Strength Factors: Arrangement of molecular chains (degree of crystallinity).
- Cross-linking Effect: Enhances thermal and chemical resistance.
Materials Science - Additional Concepts
- Molecular Mass of Polymer: Average mass of polymer molecules in a sample.
- Polydispersity Index (PDI): Ratio of weight-average molecular mass / number-average molecular mass.
- Natural Polymer PDI: 1 (approximately)
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Description
Explore the intricate concepts of dislocations and their impact on the strength of materials in this quiz. Understand the different types of dislocations, their behavior under stress, and the importance of slip systems and grain size in material strength. Perfect for students studying advanced materials science topics!
