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. The ability of a material to be rapidly cooled and not fracture
Thermal Shock Resistance
Stress Intensity values
Why do ceramics have larger bonding energy?
LASER
2. The ability of a material to absorb heat - Quantitatively: The energy required to produce a unit rise in temperature for one mole of a material.
Hardness
Heat Capacity
Not severe
Metallization
3. 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
How to gage the extent of plastic deformation
LASER
Meissner Effect
Superconductivity
4. Superconductors expel magnetic fields - This is why a superconductor will float above a magnet.
Meissner Effect
Two ways to measure heat capacity
Stages of Failure: Ductile Fracture
Force Decomposition
5. Process by which metal atoms diffuse because of a potential.
Electromigration
HB (Brinell Hardness)
Why materials fail in service
Pure Semiconductors: Conductivity vs. T
6. 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)
Ductile Fracture
Rockwell
Modulus of Rupture (MOR)
Hysteresis and Permanent Magnetization
7. Growth of an oxide layer by the reaction of oxygen with the substrate - Provides dopant masking and device isolation - IC technology uses 1. Thermal grown oxidation (dry) 2. Wet Oxidation 3. Selective Oxidation
Linewidth
Reflection of Light for Metals
Bending tests
Oxidation
8. Not ALL the light is refracted - SOME is reflected. Materials with a high index of refraction also have high reflectance - High R is bad for lens applications - since this leads to undesirable light losses or interference.
Insulators
Reflectance of Non-Metals
Opacifiers
Magnetic Storage Media Types
9. 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.
Coefficient of Thermal Expansion
Specific Heat
M is known as what?
Magnetic Storage Media Types
10. - 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
Incident Light
Stress Intensity values
Yield and Reliability
Hysteresis and Permanent Magnetization
11. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
What do magnetic moments arise from?
M is known as what?
Liquid Crystal Displays (LCD's)
Heat Capacity
12. 1. Insulators: Higher energy states NOT ACCESSIBLE due to gap 2. Semiconductors: Higher energy states separated by a smaller gap.
Slip Bands
Energy States: Insulators and Semiconductors
Griffith Crack Model
Coefficient of Thermal Expansion
13. Occur when lots of dislocations move.
Relative Permeability
Reflectance of Non-Metals
Slip Bands
Refraction
14. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW
Magnetic Storage
Metals: Resistivity vs. T - Impurities
Work Hardening
Rockwell
15. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Why materials fail in service
Liquid Crystal Displays (LCD's)
Ductile Fracture
Transparent
16. Cracks propagate along grain boundaries.
Heat Capacity
Electrical Conduction
Metallization
Intergranular Fracture
17. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Heat Capacity from an Atomic Prospective
Thermal Shock Resistance
IC Devices: P-N Rectifying Junction
Electromigration
18. As the applied field (H) increases the magnetic domains change shape and size by movement of domain boundaries.
Oxidation
Critical Properties of Superconductive Materials
Thermal expansion
Domains in Ferromagnetic & Ferrimagnetic Materials
19. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Sparkle of Diamonds
Pure Semiconductors: Conductivity vs. T
Impact energy
Incident Light
20. Increase temperature - increase in interatomic separation - thermal expansion
Not severe
Coherent
Holloman Equation
Thermal Expansion: Asymmetric curve
21. Metals are good conductors since their _______is only partially filled.
There is no perfect material?
True Strain
Valence band
Opacifiers
22. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
Soft Magnetic Materials
Heat Capacity
Opacity
Brittle Fracture
23. Elastic means reversible! This is not a permanent deformation.
Modulus of Rupture (MOR)
Luminescence
Coefficient of Thermal Expansion
Elastic Deformation
24. High toughness; material resists crack propagation.
High impact energy
LASER
Pure Semiconductors: Conductivity vs. T
Color
25. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Superconductivity
Reflection of Light for Metals
Ductile Materials
Soft Magnetic Materials
26. 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
Translucent
Thermal Conductivity
Large Hardness
4 Types of Magnetism
27. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.
Dependence of Heat Capacity on Temperature
Relative Permeability
True Stress
Holloman Equation
28. Becomes harder (more strain) to stretch (elongate)
Superconductivity
4 Types of Magnetism
Work Hardening
Intergranular Fracture
29. Emitted light is in phase
Refraction
Thermal Expansion: Symmetric curve
Coherent
Paramagnetic Materials
30. Dramatic change in impact energy is associated with a change in fracture mode from brittle to ductile.
Yield and Reliability
Ductile-to-Brittle Transition
Opaque
Oxidation
31. Liquid polymer at room T - sandwiched between two sheets of glass - coated with transparent - electrically conductive film. - Character forming letters/ numbers etched on the face - Voltage applied disrupts the orientation of the rod- shaped molecule
How an LCD works
Sparkle of Diamonds
Film Deposition
LASER
32. Specific heat = energy input/(mass*temperature change)
Iron-Silicon Alloy in Transformer Cores
Specific Heat
Generation of a Magnetic Field - Within a Solid Material
Scattering
33. Sigma=ln(li/lo)
Generation of a Magnetic Field - Within a Solid Material
True Strain
Sparkle of Diamonds
Thermal Expansion: Symmetric curve
34. Is analogous to toughness.
Griffith Crack Model
Transgranular Fracture
Hardness
Impact energy
35. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Electrical Conduction
Meissner Effect
Stress Intensity Factor
Fatigue
36. Digitalized data in the form of electrical signals are transferred to and recorded digitally on a magnetic medium (tape or disk) - This transference is accomplished by a recording system that consists of a read/write head - "write" or record data by
Thermal Stresses
Magnetic Storage Media Types
Scattering
Magnetic Storage
37. Undergo little or no plastic deformation.
Rockwell
Pure Semiconductors: Conductivity vs. T
Liquid Crystal Displays (LCD's)
Brittle Materials
38. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.
Incident Light
To improve fatigue life
How to gage the extent of plastic deformation
True Strain
39. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Fatigue
Lithography
Slip Bands
Yield and Reliability
40. Materials change size when temperature is changed
The three modes of crack surface displacement
True Stress
Specific Heat
Thermal expansion
41. Width of smallest feature obtainable on Si surface
LASER
Linewidth
Bending tests
Work Hardening
42. Typical loading conditions are _____ enough to break all inter-atomic bonds
Diamagnetic Materials
Not severe
Incident Light
Large Hardness
43. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Metals: Resistivity vs. T - Impurities
Incoherent
Ductile Fracture
Soft Magnetic Materials
44. Occurs at a single pore or other solid by refraction n = 1 for pore (air) n > 1 for the solid - n ~ 1.5 for glass - Scattering effect is maximized by pore/particle size within 400-700 nm range - Reason for Opacity in ceramics - glasses and polymers.
Meissner Effect
4 Types of Magnetism
Extrinsic Semiconductors
Scattering
45. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Shear and Tensile Stress
Holloman Equation
Iron-Silicon Alloy in Transformer Cores
Modulus of Rupture (MOR)
46. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
True Stress
Magnetic Storage Media Types
Color
Luminescence
47. Ability to transmit a clear image - The image is clear.
Extrinsic Semiconductors
Where does DBTT occur?
Transparent
Two kinds of Reflection
48. Different orientation of cleavage planes in grains.
Hard Magnetic Materials
Why fracture surfaces have faceted texture
Incoherent
Fatigue
49. If a material has ________ - then the field generated by those moments must be added to the induced field.
Electromigration
Internal magnetic moments
Lithography
Ductile Materials
50. There is always some statistical distribution of flaws or defects.
Heat Capacity
Slip Bands
There is no perfect material?
Scattering