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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. Materials change size when temperature is changed
Heat Capacity
M is known as what?
Thermal expansion
Brittle Materials
2. Allows you to calculate what happened G=F' x cos(lambda) - F=F' x cos(phi)
Two ways to measure heat capacity
Insulators
Luminescence
Force Decomposition
3. These materials are relatively unaffected by magnetic fields.
Engineering Fracture Performance
The three modes of crack surface displacement
Critical Properties of Superconductive Materials
Diamagnetic Materials
4. A high index of refraction (n value) allows for multiple internal reactions.
Sparkle of Diamonds
Thermal Expansion: Symmetric curve
Insulators
Thermal Shock Resistance
5. Metals are good conductors since their _______is only partially filled.
Valence band
Film Deposition
Influence of Temperature on Magnetic Behavior
Refraction
6. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Engineering Fracture Performance
Coherent
Influence of Temperature on Magnetic Behavior
Critical Properties of Superconductive Materials
7. Reflectiviy is between 0.90 and 0.95 - Metal surfaces appear shiny - Most of absorbed light is reflected at the same wavelength (NO REFRACTION) - Small fraction of light may be absorbed - Color of reflected light depends on wavelength distribution of
Reflection of Light for Metals
LASER
Fourier's Law
Lithography
8. 1. Tensile (opening) 2. Sliding 3. Tearing
Plastic Deformation (Metals)
Insulators
The three modes of crack surface displacement
Brittle Fracture
9. These are liquid crystal polymers- not your normal "crystal" -Rigid - rod shaped molecules are aligned even in liquid form.
10. Because of ionic & covalent-type bonding.
Why do ceramics have larger bonding energy?
Where does DBTT occur?
High impact energy
4 Types of Magnetism
11. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
Impact - Toughness
True Stress
Opaque
Dependence of Heat Capacity on Temperature
12. They are used to assess properties of ceramics & glasses.
Luminescence examples
Bending tests
Translucent
The Transistor
13. Plastic means permanent! When a small load is applied - bonds stretch & planes shear. Then when the load is no longer applied - the planes are still sheared.
Plastic Deformation (Metals)
Fourier's Law
Translucent
Holloman Equation
14. 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.
Intrinsic Semiconductors
Hysteresis and Permanent Magnetization
Shear and Tensile Stress
Impact energy
15. 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
Opacity
Extrinsic Semiconductors
Thermal expansion
16. heat flux = -(thermal conductivity)(temperature gradient) - Defines heat transfer by CONDUCTION
17. Defines the ability of a material to resist fracture even when a flaw exists - Directly depends on size of flaw and material properties - K(ic) is a materials constant
Superconductivity
Stress Intensity Factor
Extrinsic Semiconductors
Thermal expansion
18. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.
Conduction & Electron Transport
Lithography
Two ways to measure heat capacity
Transgranular Fracture
19. Light Amplification by Stimulated Emission of Radiation
LASER
True Stress
Heat Capacity
Opaque
20. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Heat Capacity from an Atomic Prospective
Generation of a Magnetic Field - Vacuum
Stress Intensity Factor
Incident Light
21. 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
Etching
Oxidation
High impact energy
Luminescence
22. 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.
Scattering
IC Devices: P-N Rectifying Junction
Intergranular Fracture
Why materials fail in service
23. Dimples on fracture surface correspond to microcavities that initiate crack formation.
4 Types of Magnetism
Thermal Shock Resistance
Ductile Fracture
Color
24. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW
HB (Brinell Hardness)
Film Deposition
Metals: Resistivity vs. T - Impurities
Luminescence
25. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
Pure Semiconductors: Conductivity vs. T
Thermal Stresses
What do magnetic moments arise from?
Metals: Resistivity vs. T - Impurities
26. Cracks pass through grains - often along specific crystal planes.
Color
Transgranular Fracture
Two kinds of Reflection
Electrical Conduction
27. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Incoherent
Hard Magnetic Materials
Impact - Toughness
Not severe
28. 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.
Reflectance of Non-Metals
Etching
Intergranular Fracture
There is no perfect material?
29. 1. Yield = ratio of functional chips to total # of chips - Most yield loss during wafer processing - b/c of complex 2. Reliability - No device has infinite lifetime. Statistical methods to predict expected lifetime - Failure mechanisms: Diffusion reg
Why fracture surfaces have faceted texture
Energy States: Insulators and Semiconductors
Luminescence
Yield and Reliability
30. Transformer cores require soft magnetic materials - which are easily magnetized and de-magnetized - and have high electrical resistivity - Energy losses in transformers could be minimized if their cores were fabricated such that the easy magnetizatio
Charpy or Izod test
Two ways to measure heat capacity
Iron-Silicon Alloy in Transformer Cores
Linewidth
31. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Impact energy
Lithography
Thermal Conductivity
Brittle Fracture
32. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.
True Strain
Thermal Shock Resistance
Where does DBTT occur?
Incoherent
33. Ohms Law: voltage drop = current * resistance
Impact - Toughness
Fourier's Law
Opacifiers
Electrical Conduction
34. Elastic means reversible! This is not a permanent deformation.
The Transistor
Elastic Deformation
Oxidation
Iron-Silicon Alloy in Transformer Cores
35. Typical loading conditions are _____ enough to break all inter-atomic bonds
Opacifiers
Paramagnetic Materials
Bending tests
Not severe
36. Degree of opacity depends on size and number of particles - Opacity of metals is the result of conduction electrons absorbing photons in the visible range.
Etching
Lithography
Impact energy
Opacity
37. Is analogous to toughness.
Hysteresis and Permanent Magnetization
Pure Semiconductors: Conductivity vs. T
Impact energy
Hard Magnetic Materials
38. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Refraction
Metallization
Why fracture surfaces have faceted texture
Charpy or Izod test
39. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Fatigue
Sparkle of Diamonds
Brittle Ceramics
The Transistor
40. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
HB (Brinell Hardness)
Elastic Deformation
Hardness
Electrical Conduction
41. Cracks propagate along grain boundaries.
Diamagnetic Materials
Intergranular Fracture
M is known as what?
Hard Magnetic Materials
42. 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.
Opacity
Pure Semiconductors: Conductivity vs. T
M is known as what?
Fatigue
43. 1. Metals: Thermal energy puts many electrons into a higher energy state. 2. Energy States: Nearby energy states are accessible by thermal fluctuations.
Large Hardness
Sparkle of Diamonds
Conduction & Electron Transport
Film Deposition
44. A measure of the ease with which a B field can be induced inside a material.
Energy States: Insulators and Semiconductors
Relative Permeability
Internal magnetic moments
Thermal expansion
45. Undergo extensive plastic deformation prior to failure.
Thermal expansion
Oxidation
Ductile Materials
Pure Semiconductors: Conductivity vs. T
46. Hardness is the resistance of a material to deformation by indentation - Useful in quality control - Hardness can provide a qualitative assessment of strength - Hardness cannot be used to quantitatively infer strength or ductility.
Force Decomposition
Magnetic Storage
Hardness
Critical Properties of Superconductive Materials
47. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
Reflection of Light for Metals
Magnetic Storage Media Types
What do magnetic moments arise from?
Ductile Materials
48. 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)
LASER
Reflectance of Non-Metals
Rockwell
Ductile Materials
49. 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
The three modes of crack surface displacement
Magnetic Storage
Thermal Expansion: Symmetric curve
Holloman Equation
50. Becomes harder (more strain) to stretch (elongate)
Work Hardening
Thermal Conductivity
Domains in Ferromagnetic & Ferrimagnetic Materials
Ductile Fracture