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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. With Increasing temperature - the saturation magnetization diminishes gradually and then abruptly drops to zero at Curie Temperature - Tc.
Yield and Reliability
Two kinds of Reflection
Influence of Temperature on Magnetic Behavior
To improve fatigue life
2. 1. Tensile (opening) 2. Sliding 3. Tearing
Force Decomposition
Rockwell
The three modes of crack surface displacement
Dependence of Heat Capacity on Temperature
3. 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.
Brittle Materials
Specific Heat
Influence of Temperature on Magnetic Behavior
Insulators
4. 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
Ductile Materials
How an LCD works
Opaque
Slip Bands
5. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
Refraction
Ductile Materials
Magnetic Storage Media Types
Why do ceramics have larger bonding energy?
6. Resistance to plastic deformation of cracking in compression - and better wear properties.
Brittle Ceramics
Yield and Reliability
Large Hardness
Rockwell
7. 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
Heat Capacity from an Atomic Prospective
4 Types of Magnetism
Brittle Materials
Superconductivity
8. The size of the material changes with a change in temperature - polymers have the largest values
HB (Brinell Hardness)
Coefficient of Thermal Expansion
Heat Capacity
Why materials fail in service
9. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Energy States: Insulators and Semiconductors
Metallization
Opaque
How an LCD works
10. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Fatigue
Holloman Equation
Soft Magnetic Materials
HB (Brinell Hardness)
11. Without passing a current a continually varying magnetic field will cause a current to flow
Stress Intensity values
Opacity
Refraction
Response to a Magnetic Field
12. 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
Lithography
Impact - Toughness
The three modes of crack surface displacement
Stress Intensity Factor
13. # of thermally generated electrons = # of holes (broken bonds)
Slip Bands
Electrical Conduction
4 Types of Magnetism
Intrinsic Semiconductors
14. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Holloman Equation
Incident Light
Stages of Failure: Ductile Fracture
To improve fatigue life
15. If a material has ________ - then the field generated by those moments must be added to the induced field.
Pure Semiconductors: Conductivity vs. T
The three modes of crack surface displacement
Translucent
Internal magnetic moments
16. Sigma=ln(li/lo)
Coefficient of Thermal Expansion
True Strain
4 Types of Magnetism
Metals: Resistivity vs. T - Impurities
17. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Opacity
Hard Magnetic Materials
Magnetic Storage
IC Devices: P-N Rectifying Junction
18. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Modulus of Rupture (MOR)
Metallization
Pure Semiconductors: Conductivity vs. T
Ductile Fracture
19. 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
Ductile-to-Brittle Transition
To improve fatigue life
Thermal Conductivity
Stress Intensity values
20. Process by which metal atoms diffuse because of a potential.
Thermal Conductivity
Conduction & Electron Transport
What do magnetic moments arise from?
Electromigration
21. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.
Holloman Equation
Ductile Fracture
Why do ceramics have larger bonding energy?
Thermal expansion
22. Stress concentration at a crack tips
Luminescence
Griffith Crack Model
Opacifiers
What do magnetic moments arise from?
23. 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
Refraction
Brittle Fracture
Stress Intensity Factor
Critical Properties of Superconductive Materials
24. 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.
Opaque
Shear and Tensile Stress
Metallization
Insulators
25. Undergo little or no plastic deformation.
To improve fatigue life
Brittle Materials
Extrinsic Semiconductors
Influence of Temperature on Magnetic Behavior
26. Measures impact energy 1. Strike a notched sample with an anvil 2. Measure how far the anvil travels following impact 3. Distance traveled is related to energy required to break the sample 4. Very high rate of loading. Makes materials more "brittle."
Charpy or Izod test
Opacifiers
Translucent
There is no perfect material?
27. Cracks pass through grains - often along specific crystal planes.
Intrinsic Semiconductors
Heat Capacity from an Atomic Prospective
Plastic Deformation (Metals)
Transgranular Fracture
28. Ohms Law: voltage drop = current * resistance
Holloman Equation
Electrical Conduction
Luminescence
True Stress
29. Metals are good conductors since their _______is only partially filled.
Brittle Fracture
Valence band
How an LCD works
Intergranular Fracture
30. 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
Stages of Failure: Ductile Fracture
Thermal Stresses
Oxidation
Bending tests
31. 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.
Slip Bands
Why do ceramics have larger bonding energy?
Opaque
Extrinsic Semiconductors
32. There is always some statistical distribution of flaws or defects.
Linewidth
Valence band
There is no perfect material?
Charpy or Izod test
33. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Lithography
Yield and Reliability
Dependence of Heat Capacity on Temperature
Refraction
34. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
HB (Brinell Hardness)
Pure Semiconductors: Conductivity vs. T
Magnetic Storage Media Types
Diamagnetic Materials
35. 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.
Charpy or Izod test
Shear and Tensile Stress
Engineering Fracture Performance
Opacity
36. These materials are "attracted" to magnetic fields.
Transgranular Fracture
Stress Intensity Factor
Paramagnetic Materials
M is known as what?
37. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW
Where does DBTT occur?
Metals: Resistivity vs. T - Impurities
Relative Permeability
IC Devices: P-N Rectifying Junction
38. Specific heat = energy input/(mass*temperature change)
Thermal Expansion: Symmetric curve
Specific Heat
Reflection of Light for Metals
4 Types of Magnetism
39. A three terminal device that acts like a simple "on-off" switch. (the basis of Integrated Circuits (IC) technology - used in computers - cell phones - automotive control - etc) - If voltage (potential) applied to the "gate" - current flows between th
Heat Capacity from an Atomic Prospective
Engineering Fracture Performance
The Transistor
Stages of Failure: Ductile Fracture
40. Becomes harder (more strain) to stretch (elongate)
Generation of a Magnetic Field - Within a Solid Material
Hysteresis and Permanent Magnetization
Work Hardening
High impact energy
41. Materials change size when temperature is changed
Two ways to measure heat capacity
Incident Light
Thermal expansion
Domains in Ferromagnetic & Ferrimagnetic Materials
42. Increase temperature - no increase in interatomic separation - no thermal expansion
Thermal Expansion: Symmetric curve
Domains in Ferromagnetic & Ferrimagnetic Materials
Electrical Conduction
Stress Intensity Factor
43. Wet: isotropic - under cut Dry: ansiotropic - directional
Brittle Fracture
Metallization
Shear and Tensile Stress
Etching
44. Undergo extensive plastic deformation prior to failure.
There is no perfect material?
High impact energy
Ductile Materials
Pure Semiconductors: Conductivity vs. T
45. Cracks propagate along grain boundaries.
Rockwell
Dependence of Heat Capacity on Temperature
True Stress
Intergranular Fracture
46. Different orientation of cleavage planes in grains.
Why fracture surfaces have faceted texture
Lithography
Opacity
Magnetic Storage Media Types
47. A high index of refraction (n value) allows for multiple internal reactions.
Sparkle of Diamonds
The Transistor
Dependence of Heat Capacity on Temperature
Holloman Equation
48. For a metal - there is no ______ - only reflection
Refraction
The Transistor
Force Decomposition
Heat Capacity from an Atomic Prospective
49. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Fatigue
Two kinds of Reflection
Two ways to measure heat capacity
To improve fatigue life
50. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
To improve fatigue life
There is no perfect material?
Meissner Effect
Superconductivity