Metallic Crystal Structures Quiz
40 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What process involves atoms migrating from an interstitial position to an empty one?

  • Thermal Diffusion
  • Molecular Dynamics
  • Vacancy Diffusion
  • Interstitial Diffusion (correct)

    • What does Fick's First Law relate to in the context of diffusion?

  • Mass transfer rate of elements over time (correct)
  • Volume changes during state transitions
  • Pressure dependency of materials
  • Time dependency of temperature changes

    • What is defined as the minimum temperature required for a solid to change into liquid?

  • Boiling point
  • Melting point (correct)
  • Freezing point
  • Thermal point

    • Which term describes the weight of a material, indicating heavier materials with higher values?

    <p>Density</p> Signup and view all the answers

    What mechanism describes the interchange of atoms from their regular lattice positions to vacant sites?

    <p>Vacancy Diffusion</p> Signup and view all the answers

    Which of the following represents the quantity of voids in solid materials?

    <p>Porosity</p> Signup and view all the answers

    What is the definition of Diffusion Flux?

    <p>The mass of atoms diffusing per unit area per unit time</p> Signup and view all the answers

    What type of microscopy uses an electron beam that passes through a specimen?

    <p>Transmission Electron Microscopy</p> Signup and view all the answers

    What best describes a unit cell in crystalline structures?

    <p>A basic structural unit that defines crystal composition.</p> Signup and view all the answers

    Which of the following elements is known to display a simple-cubic crystal structure?

    <p>Polonium</p> Signup and view all the answers

    In a Face-Centered Cubic (FCC) unit cell, how many total atoms are accounted for?

    <p>8 atoms</p> Signup and view all the answers

    What is the relationship for calculating the edge length (a) of a Face-Centered Cubic unit cell in terms of atomic radius (R)?

    <p>a = 2R√2</p> Signup and view all the answers

    Which of the following best describes the bonding nature in metallic crystal structures?

    <p>Non-directional and metallic bonding.</p> Signup and view all the answers

    How many types of crystal structures are specifically mentioned?

    <p>3 types</p> Signup and view all the answers

    In Hexagonal Close-Packed structures, how many atoms are on the top and bottom faces of the unit cell?

    <p>6 atoms</p> Signup and view all the answers

    What does the formula N = Ni + Nf/2 + Nc/6 represent in crystal structures?

    <p>Calculation of total number of atoms per cell.</p> Signup and view all the answers

    What is the primary purpose of a tension test?

    <p>To apply tensile load along the long axis of a specimen</p> Signup and view all the answers

    Which property of material describes its ability to absorb energy and deform plastically without fracturing?

    <p>Toughness</p> Signup and view all the answers

    What does Poisson's ratio (v) represent in material science?

    <p>The ratio of lateral strain to axial strain</p> Signup and view all the answers

    In which test is a specimen subjected to pure shear force?

    <p>Shear Test</p> Signup and view all the answers

    What characteristic of a material is defined as its ability to resist permanent shape change?

    <p>Hardness</p> Signup and view all the answers

    What does resilience in material properties refer to?

    <p>The energy absorbed during elastic deformation</p> Signup and view all the answers

    What property pertains to the ease with which a material can be deformed under compressive stress?

    <p>Malleability</p> Signup and view all the answers

    During which test does a structural member undergo twisting?

    <p>Torsion Test</p> Signup and view all the answers

    What characterizes a tilt boundary?

    <p>It is formed by aligned edge dislocations.</p> Signup and view all the answers

    Which technique is used for determining grain size by counting intersections?

    <p>Linear Intercept</p> Signup and view all the answers

    What type of boundary is characterized by a mirror lattice symmetry?

    <p>Twin Boundary</p> Signup and view all the answers

    Which of the following is a type of defect in three dimensions?

    <p>Volume Defects</p> Signup and view all the answers

    What does diffusion primarily refer to?

    <p>The process of atoms moving from high to low concentration</p> Signup and view all the answers

    Which term refers to the process where atoms from one metal diffuse into another?

    <p>Interdiffusion</p> Signup and view all the answers

    What is the basic function of optical microscopy in the context of microstructure study?

    <p>It studies microstructures using light and illumination systems.</p> Signup and view all the answers

    How are atomic vibrations related to the properties of solid materials?

    <p>They reflect the displacement of atoms out of their lattice positions.</p> Signup and view all the answers

    What characterizes steady state diffusion?

    <p>The flux remains constant and independent of time.</p> Signup and view all the answers

    What is the significance of the boiling point?

    <p>It is the minimum temperature necessary for a liquid to become gas.</p> Signup and view all the answers

    Which statement accurately describes unsteady state diffusion?

    <p>The concentration gradient is not uniform across the plate.</p> Signup and view all the answers

    How is specific gravity determined?

    <p>By comparing the density of a material to the density of a reference substance.</p> Signup and view all the answers

    What does Fick’s Second Law address?

    <p>The relationship between flux and concentration gradient over time.</p> Signup and view all the answers

    What does the term 'stress' refer to in mechanical properties?

    <p>The instantaneous load divided by the original cross-sectional area.</p> Signup and view all the answers

    What does the size and shape of a material influence?

    <p>The diffusion rate into and out of the material.</p> Signup and view all the answers

    What does 'strain' refer to in the context of materials?

    <p>The deformation experienced by a material relative to its original dimensions.</p> Signup and view all the answers

    Study Notes

    Metallic Crystal Structures

    • Metallic crystal structures are characterized by metallic bonding, which is non-directional in nature.
    • Three common crystal structures in metals are:
      • Face-Centered Cubic (FCC)
      • Body-Centered Cubic (BCC)
      • Hexagonal Close-Packed (HCP)

    Face-Centered Cubic (FCC) Crystal Structure

    • Found in metals like copper, aluminum, silver, and gold.
    • Has a cubic unit cell with atoms located at the corners and centers of all the cube faces.
    • Each unit cell contains 6 atoms.

    Body-Centered Cubic (BCC) Crystal Structure

    • Has a cubic unit cell with atoms located at the corners and one in the center of the cube.
    • Contains 2 atoms per unit cell.
    • Examples include iron, chromium, and tungsten.

    Hexagonal Close-Packed (HCP) Crystal Structure

    • Has a unit cell with a hexagonal top and bottom face with six atoms.
    • Each face is separated by a plane in the middle of the cell that contributes three additional atoms, for a total of nine atoms per unit cell.
    • Examples include magnesium, zinc, and titanium.

    Point Defects in Solid Solutions

    • Point defects are imperfections at atomic level.
    • Two common types:
      • Vacancy: A missing atom from its regular lattice position.
      • Interstitial Atom: An extra atom inserted into the crystal lattice.

    Grain Size

    • Grain size refers to the average size of the crystalline grains in a polycrystalline material.
    • Smaller grain sizes generally increase the strength and hardness of a material.

    Diffusion in Solids

    • Diffusion is the movement of atoms, ions, or molecules from a region of higher concentration to a region of lower concentration.
    • Types of diffusion:
      • Interdiffusion/Impurity Diffusion: The movement of atoms of one metal into another.
      • Self-Diffusion: The interchange of positions between atoms of the same type.

    Diffusion Mechanisms

    • Two main mechanisms:
      • Vacancy Diffusion: Atoms move to adjacent vacant lattice sites.
      • Interstitial Diffusion: Atoms move between interstitial positions in the crystal lattice.

    Fick's Laws of Diffusion

    • Fick's First Law: Describes steady-state diffusion, where the diffusion flux is constant over time.
    • Fick's Second Law: Describes unsteady-state diffusion, where the diffusion flux changes with time.

    Physical Properties of Materials

    • Physical properties describe how a material interacts with its environment. Key physical properties include:
      • Density: Mass per unit volume.
      • Porosity: The volume fraction of voids within a material.
      • Melting Point: The temperature at which a solid transforms into a liquid.
      • Boiling Point: The temperature at which a liquid transforms into a gas.
      • Specific Gravity: The ratio of the density of a material to the density of a reference material.
      • Color: The reflective property of a material.
      • Size and Shape: The dimensions of a material.

    Mechanical Properties of Materials

    • Mechanical properties describe how a material responds to applied forces. Key mechanical properties include:
      • Stress: The force acting on a unit area of a material.
      • Strain: The deformation of a material under stress.
      • Elastic Deformation: Reversible deformation that disappears when the stress is removed.
      • Plastic Deformation: Permanent deformation that remains after the stress is removed.
      • Resilience: The ability of a material to absorb energy during elastic deformation.
      • Toughness: The ability of a material to absorb energy before fracture.
      • Hardness: The material's resistance to permanent indentation.
      • Hardenability: The ability of a material to attain hardness through heat treatment.
      • Brittleness: The tendency of a material to fracture easily without significant plastic deformation.
      • Malleability: The ability of a material to deform under compressive stress without fracture.
      • Ductility: The ability of a material to deform under tensile stress without fracture.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Naval Material Reviewer PDF

    Description

    Test your knowledge on metallic crystal structures, including Face-Centered Cubic (FCC), Body-Centered Cubic (BCC), and Hexagonal Close-Packed (HCP) structures. Explore the unique characteristics, examples, and configurations of these common metallic arrangements.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser