SUBJECTS
|
BROWSE
|
CAREER CENTER
|
POPULAR
|
JOIN
|
LOGIN
Business Skills
|
Soft Skills
|
Basic Literacy
|
Certifications
About
|
Help
|
Privacy
|
Terms
|
Email
Search
Test your basic knowledge |
Engineering Materials
Start Test
Study First
Subject
:
engineering
Instructions:
Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can
study here
.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.
This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Loss of image transmission - You get no image - There is no light transmission - and therefore reflects - scatters - or absorbs ALL of it. Both mirrors and carbon black are opaque.
Opaque
Luminescence examples
Rockwell
Valence band
2. Cracks propagate along grain boundaries.
Modulus of Rupture (MOR)
Intergranular Fracture
Response to a Magnetic Field
4 Types of Magnetism
3. Typical loading conditions are _____ enough to break all inter-atomic bonds
Bending tests
Specific Heat
Not severe
Rockwell
4. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.
Fatigue
Generation of a Magnetic Field - Vacuum
Engineering Fracture Performance
To improve fatigue life
5. Elastic means reversible! This is not a permanent deformation.
Impact energy
Hardness
Reflectance of Non-Metals
Elastic Deformation
6. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
The Transistor
Critical Properties of Superconductive Materials
Pure Semiconductors: Conductivity vs. T
Stress Intensity Factor
7. If a material has ________ - then the field generated by those moments must be added to the induced field.
The Transistor
Modulus of Rupture (MOR)
Internal magnetic moments
Linewidth
8. Resistance to plastic deformation of cracking in compression - and better wear properties.
Thermal expansion
Reflectance of Non-Metals
Large Hardness
Work Hardening
9. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
There is no perfect material?
Incident Light
Linewidth
Domains in Ferromagnetic & Ferrimagnetic Materials
10. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Domains in Ferromagnetic & Ferrimagnetic Materials
Dependence of Heat Capacity on Temperature
HB (Brinell Hardness)
Conduction & Electron Transport
11. Allows you to calculate what happened G=F' x cos(lambda) - F=F' x cos(phi)
LASER
Force Decomposition
Thermal Expansion: Symmetric curve
Impact energy
12. 1. Fluorescent Lamp - tungstate or silicate coating on inside of tube emits white light due to UV light generated inside the tube. 2. TV screen - emits light as electron beam is scanned back and forth.
M is known as what?
Stress Intensity Factor
Elastic Deformation
Luminescence examples
13. Measures Hardness - No major sample damage - Each scales runs to 130 but only useful in range 20-100 - Minor load is 10 kg - Major load: 60 kg (diamond) - 100 kg (1/16 in. ball) - 150 kg (diamond)
Rockwell
Electrical Conduction
Luminescence examples
Sparkle of Diamonds
14. Occur when lots of dislocations move.
Slip Bands
Generation of a Magnetic Field - Within a Solid Material
Why materials fail in service
Charpy or Izod test
15. A measure of the ease with which a B field can be induced inside a material.
Electromigration
Relative Permeability
Stress Intensity values
Opacifiers
16. - Metals that exhibit high ductility - exhibit high toughness. Ceramics are very strong - but have low ductility and low toughness - Polymers are very ductile but are not generally very strong in shear (compared to metals and ceramics). They have low
Yield and Reliability
Paramagnetic Materials
Reflection of Light for Metals
Stress Intensity values
17. Rho=F/A - tau=G/A . Depending on what angle the force is applied - and what angle the crystal is at - it takes different amounts of force to induce plastic deformation.
Reflection of Light for Metals
Shear and Tensile Stress
Lithography
Opacifiers
18. Transmitted light distorts electron clouds - The velocity of light in a material is lower than in a vacuum - Adding large ions to glass decreases the speed of light in the glass - Light can be "bent" (or refracted) as it passes through a transparent
Coefficient of Thermal Expansion
Incident Light
Refraction
IC Devices: P-N Rectifying Junction
19. 1. Tc= critical temperature- if T>Tc not superconducting 2. Jc= critical current density - if J>Jc not superconducting 3. Hc= critical magnetic field - if H > Hc not superconducting
Color
Critical Properties of Superconductive Materials
Not severe
Ductile Materials
20. ...occurs in bcc metals but not in fcc metals.
Force Decomposition
Where does DBTT occur?
How an LCD works
Holloman Equation
21. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow
Paramagnetic Materials
Stress Intensity Factor
IC Devices: P-N Rectifying Junction
Coherent
22. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture
Stages of Failure: Ductile Fracture
Iron-Silicon Alloy in Transformer Cores
Incoherent
Luminescence
23. Diffuse image
Heat Capacity
Ductile Materials
Translucent
Coherent
24. Wet: isotropic - under cut Dry: ansiotropic - directional
Why materials fail in service
There is no perfect material?
Scattering
Etching
25. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
Engineering Fracture Performance
Magnetic Storage Media Types
Incident Light
Pure Semiconductors: Conductivity vs. T
26. 1. Ductility- % elongation - % reduction in area - may be of use in metal forming operations (e.g. - stretch forming). This is convenient for mechanical testing - but not very meaningful for most deformation processing. 2. Toughness- Area beneath str
Stress Intensity Factor
Dependence of Heat Capacity on Temperature
Specific Heat
How to gage the extent of plastic deformation
27. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Translucent
Ductile Fracture
Internal magnetic moments
4 Types of Magnetism
28. The ability of a material to transport heat - Atomic Perspective: Atomic vibrations and free electrons in hotter regions transport energy to cooler regions - Metals have the largest values
Thermal Conductivity
Elastic Deformation
Modulus of Rupture (MOR)
Impact - Toughness
29. Metals are good conductors since their _______is only partially filled.
Valence band
Intergranular Fracture
Rockwell
Shear and Tensile Stress
30. The magnetic hysteresis phenomenon: Stage 1: Initial (unmagnetized state) Stage 2: Apply H - align domains Stage 3: Remove H - alignment remains => Permanent magnet Stage 4: Coercivity - Hc negative H needed to demagnitize Stage 5: Apply -H - align d
Not severe
Shear and Tensile Stress
Hysteresis and Permanent Magnetization
Work Hardening
31. 1. Insulators: Higher energy states NOT ACCESSIBLE due to gap 2. Semiconductors: Higher energy states separated by a smaller gap.
Diamagnetic Materials
Energy States: Insulators and Semiconductors
Holloman Equation
Luminescence
32. They are used to assess properties of ceramics & glasses.
Yield and Reliability
Thermal Shock Resistance
Insulators
Bending tests
33. A parallel-plate capacitor involves an insulator - or dielectric - between two metal electrodes. The charge density buildup at the capacitor surface is related to the dielectric constant of the material.
Charpy or Izod test
Why materials fail in service
Insulators
Conduction & Electron Transport
34. - The emission of light from a substance due to the absorption of energy. (Could be radiation - mechanical - or chemical energy. Could also be energetic particles.) - Traps and activator levels are produced by impurity additions to the material - Whe
Iron-Silicon Alloy in Transformer Cores
The three modes of crack surface displacement
Luminescence
Metallization
35. Cracks pass through grains - often along specific crystal planes.
Specific Heat
Why materials fail in service
Transgranular Fracture
Ductile-to-Brittle Transition
36. The size of the material changes with a change in temperature - polymers have the largest values
Coefficient of Thermal Expansion
Conduction & Electron Transport
Superconductivity
Response to a Magnetic Field
37. There is always some statistical distribution of flaws or defects.
There is no perfect material?
HB (Brinell Hardness)
Why fracture surfaces have faceted texture
Hardness
38. Undergo extensive plastic deformation prior to failure.
Ductile Materials
Response to a Magnetic Field
Energy States: Insulators and Semiconductors
How an LCD works
39. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Hysteresis and Permanent Magnetization
Fatigue
HB (Brinell Hardness)
Refraction
40. 1. Ability of the material to absorb energy prior to fracture 2. Short term dynamic stressing - Car collisions - Bullets - Athletic equipment 3. This is different than toughness; energy necessary to push a crack (flaw) through a material 4. Useful in
Heat Capacity
Translucent
Work Hardening
Impact - Toughness
41. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Luminescence
Intergranular Fracture
Lithography
Dependence of Heat Capacity on Temperature
42. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
HB (Brinell Hardness)
Electrical Conduction
Intergranular Fracture
Relative Permeability
43. Dramatic change in impact energy is associated with a change in fracture mode from brittle to ductile.
How an LCD works
Ductile-to-Brittle Transition
IC Devices: P-N Rectifying Junction
Internal magnetic moments
44. 1. Diamagnetic (Xm ~ 10^-5) - small and negative magnetic susceptibilities 2. Paramagnetic (Xm ~ 10^-4) - small and positive magnetic susceptibilities 3. Ferromagnetic - large magnetic susceptibilities 4. Ferrimagnetic (Xm as large as 10^6) - large m
Specific Heat
4 Types of Magnetism
The three modes of crack surface displacement
Plastic Deformation (Metals)
45. 1. Tensile (opening) 2. Sliding 3. Tearing
Thermal Conductivity
Stress Intensity Factor
Where does DBTT occur?
The three modes of crack surface displacement
46. Ohms Law: voltage drop = current * resistance
Two ways to measure heat capacity
Ductile Materials
Heat Capacity
Electrical Conduction
47. Is analogous to toughness.
Brittle Materials
Impact energy
Metals: Resistivity vs. T - Impurities
Refraction
48. Materials change size when temperature is changed
Luminescence
Translucent
Oxidation
Thermal expansion
49. The Magnetization of the material - and is essentially the dipole moment per unit volume. It is proportional to the applied field. Xm is the magnetic susceptibility.
Transgranular Fracture
Magnetic Storage Media Types
Why materials fail in service
M is known as what?
50. Becomes harder (more strain) to stretch (elongate)
Coefficient of Thermal Expansion
IC Devices: P-N Rectifying Junction
Work Hardening
Why materials fail in service