CHEMISTRY OF ENGINEERING MATERIALS Flashcards
1
Q
WHAT ARE THE FOUR ENGINEERING MATERIALS?
A
POLYMERS, CERAMICS, METALS & ALLOYS, COMPOSITES
2
Q
What are the three types of polymers?
A
Thermoplastic Polymers, Thermosetting Polymers, Elastomers
3
Q
It is a solid material which is hard, shiny, malleable, fusible and ductile, with good electric and thermal conductivity
A
Metal
4
Q
Which of the following is not a characteristic of a metal?
A. Malleable & Fusible
B. Hard
C. Shiny & Ductile
D. Brittle
A
Brittle
5
Q
A material composed of two or more metals or a metal and nonmetal
A
Alloy
6
Q
Below are examples of alloys except
A. Brass
B. Bronze & Copper
C. Manganese
D. Cast Iron
A
Manganese
7
Q
Below are examples of metals except
A. Iron & Gold
B. Silver
C. Diamond
D. Aluminum
A
Diamond
8
Q
What are the two categories of metals and alloys
A
Ferrous and Non-ferrous
9
Q
3 categories of non-ferrous
A
Cu-Alloys, Ni-Alloys, Al-Alloys
10
Q
2 categories of ferrous
A
Steels and Cast Irons
11
Q
2 categories of steels
A
Alloy Steels, Plain Carbon Steels
12
Q
5 categories of cast iron
A
white cast iron, malleable cast iron, grey cast iron, S.G. cast iron, and chilled cast iron
13
Q
It has iron as its main constitute
A
Ferrous
14
Q
Has carbon of less than 2%
A
Steel
15
Q
Has carbon of more than 2%
A
Cast Iron
16
Q
Has other than iron as main constitute
A
Non-ferrous
17
Q
Has aluminum as main constitute
A
Al-alloy
18
Q
Has nickel as main constitute
A
Ni-alloy
19
Q
Has copper as main constitute
A
Cu-alloy
20
Q
Poly means
A
Many
21
Q
Meros means
A
Units, Parts
22
Q
Polymer means
A
Many parts/many units
23
Q
Other name for thermoplastic
A
Thermosoftening Plastic
24
Q
This polymer have their chains crossed linked by covalent bonds
A
Thermosetting Polymer
25
True or False. The resulting three-dimensional structure of thermosetting can be changed
False
26
This type of polymer becomes pliable or moldable above a specific temperature and solidifies upon cooling
Thermoplastic Polymer/Thermosoftening Plastic
27
These are atoms pack in periodic or 3D arrays
Crystalline Materials
28
These are atoms with no periodic packing
Noncrystalline Materials
29
Amorphous means
Noncrystalline
30
Two types of solids
Crystalline and Amorphous
31
The constituent particles have a regular arrangement
Crystalline Solids
32
They do not have a sharp characteristic melting point; they generally melt over a range and temperature
Amorphous Solids
33
What do you call something with different physical properties and different directions?
Anisotropy
34
What do you call something that have physical properties that are identical in all directions along any axis?
Isotropy
35
They can be cleaved along definite planes
Crystalline Solids
36
They are characterized by random arrangement of constituent particles
Amorphous Solids
37
The following are characteristics of Amorphous Solids except
A. They are characterized by random arrangement of constituent particles
B. They are characterized by sharp melting point
C. Their physical properties are identical in all directions along any axis
D. They cannot be cleaved along definite planes; they undergo irregular breakage when cut in a knife
B, Amorphous Solids does not have a sharp melting point, and melts over a range of temperature
38
Four classes of solids
Molecular, Ionic, Covalent, Metallic
39
This type of solid consist of high melting and boiling points, they are also good conductors of heat and electricity due to the presence of mobile electrons
Metallic Solids
40
This solid is made up of atoms that are bonded together by covalent bonds
Covalent Solids
41
This type of solid consist of high melting points. However, their thermal and electrical conductivity is poor.
Covalent Solids
42
This type of solid is held together by weak Van der Waals forces
Molecular Solids
43
This type of solid is characterized by london dispersion force and dipole-dipole attractions
Molecular Solids
44
This type of solid is hard, brittle, and have high melting and boiling points
Ionic Solids
45
In this type of solid, atoms are interlinked by covalent linkages to form giant network solids
Covalent Solids
46
The following are characteristics of Ionic Solids except
A. Soft
B. Brittle
C. Have high melting & boiling points
D. Hard
A, They are hard
47
This type of solid consist of constituent particles that are positive kernels immerse in a sea of mobile electrons.
Metallic Solids
48
The following are characteristics of molecular solids except
A. Poor thermal conduction
B. Good electrical conduction
C. Soft
D. Poor electrical conduction
B, they have poor thermal and electrical conduction
49
The following are examples of molecular solids except
A. Ice
B. NaCl
C. Iodine
D. Solid Carbon Dioxide
B, NaCl is an Ionic Solid
50
The following are examples of metallic solids except
A. Diamond
B. Al
C. Ni
D. Fe
E. Cu
A, diamond is a covalent solid
51
The following are examples of covalent solids except:
A. Iodine
B. Silicon Carbide
C. Quartz
D. Silica
E. Diamond
A, iodine is a molecular solid
52
The following are examples of molecular solids except
A. Solid Carbon Dioxide
B. Iodine
C. Quartz
D. Ice
C, quartz is a covalent solid
53
They are rare due to low packing density
Simple Cubic Structure
54
In this structure, atoms touch each other along cube diagonals
Body Centered Cubic Structure
55
This structure tend to be densely packed
Metallic Crystal Structure
56
This structure have the simplest crystal structure
Metallic Crystal Structure
57
This structure is characterized by stacking sequence like ABAB
Hexagonal Close-Packed Structure
58
The coordination number of this structure is 6
Simple Cubic Structure
59
The coordination number of this structure is 12 and has 4 atoms per unit cell
Face Centered Cubic Structure
60
This refers to number of atoms or ions that surround a central atom or ion in a chemical compound
Coordination number
61
This structure has a coordination number of 8
Body Centered Cubic Structure
62
The coordination number of this structure is 12 and has 6 atoms per unit cell
Hexagonal Close-Packed Structure
63
It helps determine the geometric shape and stability of compound. They also determine the structure & arrangement of atoms or ions on the crystal structure
Coordination number
64
This structure has 1 atom per unit cell
Simple Cubic Structure
65
The following are the reasons for the dense packing of Metallic Crystal Structures except
A. Metallic bonding is not directional
B. Electron cloud shields cores from each other
C. Close-packed dimensions are cube edges
D. Typically, only one element is present so all atomic radii are the same
E. Nearest neighbor distances tend to be small in order to lower bond energy.
C
66
What is the APF for a simple cubic structure?
0.52
67
What is the APF of a Hexagonal Close-Packed Structure?
0.74
68
What is the APF for a body-centered cubic structure?
0.68
69
What are the three types of cubic cells?
Simple cubic, Body-centered cubic, and Face-centered cubic
70
This structure has a 3D projection
Hexagonal Close-Packed Structure
71
Trivia: Pmetal > Pceramics > Ppolymers
72
It has less dense packing and often lighter elements
Ceramics/Semicond
73
It has close-packing (metallic bonding) and has often large atomic masses
Metals/Alloys
74
They have intermediate values
Composites/Fibers
75
They have low packing density and lighter elements
Polymers
76
True or False. Most engineering materials are polycrystals
True
77
What is the typical range of grain sizes?
1nm to 2cm
78
True or False. Each grain is a single crystal
True
79
Trivia:
Anisotropic - grain/crystals have direction
Isotropic - grain/crystals are dotted
80
Most crystalline solids are composed of a collection of many small crystals or grains, such materials are termed…?
Polycrystalline
81
If grains are randomly oriented, it is..?
Isotropic
82
If grains are randomly oriented, it is..?
Isotropic
83
If grains are textured, they are…?
Anisotropic
84
In this type of crystal, properties vary with direction
Single Crystals
85
Two or more distinct crystal structures for the same material is called…?
Allotrophy/Polymorphism
86
In this type of crystal, properties may or may not vary with direction
Polycrystals
87
Some metals, as well as nonmetals, may have more than one crystal structure, a phenomenon known as…
Polymorphism
88
When found in elemental solids, the condition is often termed…
Allotrophy
89
It is the smallest portion of a crystal lattice which produces the complete space lattice by repeating itself again and again
Unit Cell
90
What do you call the geometrical pattern of points of which the unit cells are arranged?
Crystal Lattice
91
It is the regular and repeating arrangement of particles in three-dimensional space
Crystal Lattice
92
It is the positions occupied by the particles in this three-dimensional arrangement
Lattice sites/Lattice points
93
These properties influence qualitatively and quantitatively the response of a given material to factors like temperature, magnetic field, electric current, radiations, etc.
Properties of Metals
94
What are the five physical properties of metals
Appearance, Color, Density, Melting Point, Porosity
95
It is the property which influences the processing of metal and their alloys during industrial operation
Technological Properties
96
This property describe the behavior of metal under the action of external forces
Mechanical Properties
97
This property refer to the behavior of the substance under magnetic field
Magnetic Properties
98
Property of materials that include dimensions, appearance, color, density, melting point, porosity, etc.
Physical Properties
99
This property study the response of a material to the application of heat
Thermal Properties
100
In this property, metals tend to suffer chemical deterioration on coming in contact with other substances
Chemical Properties
101
What are the five importance chemical properties of metals
Corrosion resistance, Chemical composition, Reactivity, Acidity, Alkalinity
102
This property refers to the selection of metal and material for electric equipments that is done on the basis of their electrical properties
Electrical Properties
103
These two elements are used for making electric wires because of their good conductivity
Copper and Silver
104
What are the seven properties of metals?
Physical, Thermal, Electrical, Chemical, Mechanical, Technological, and Magnetic Properties
105
What are the four technological properties of metals?
Castability, Machinability, Weldability, and Workability/Formability
106
What are the three magnetic properties of metals?
Diamagnetism, Paramagnetism, and Ferromagnetism
107
What are the six thermal properties of metals?
Heat capacity and specific heat
Thermal expension
Melting point
Thermal conductivity
Thermal shock resistance
Thermal stability
108
What are the 13 mechanical properties of metals
Elasticity
Plasticity
Toughness
Resilience
Tensile Strength
Shear Strength
Ductility
Malleability
Brittleness
Hardness
Fatigue
Creep
Wear Resistance
109
It is the ratio of the volume occupied by the pores to the volume of a material
Porosity
110
This refers to the ability of a metal to withstand changes without undergoing any permanent change in dimensions, without cracking or peeling off
Thermal Stability
111
It is the ability of a material to seek its original dimensions when the deforming force is removed
Elasticity
112
It is the ratio of the maximum load to the original cross-sectional area
Tensile Strength
113
It is the property which enables a material to withstand forces acting upon it with a tendency to distort its shape
Shear Strength
114
It is the rate at which heat can flow through a material hnder the influence of a given temperature gradient
Thermal Conductivity
115
It is the property of a substancr that possesses if it contains one or more unpaired electrons
Paramagnetism
116
It is the capacity of a material to be welded under the given fabrication conditions of heat and pressure, and perform satisfactorily in the intended service
Weldability
117
It is the type of magnetism that cause a substance with no unpaired electrons to be weakly repelled from a magnetic field
Diamagnetism
118
It is the continuous deformation of a machine part by the action of load at elevated temperates
Creep
119
It is the opposite of toughess anc is the property of a material which does not permit permanent deformation without breakage
Brittleness
120
It is the unintentional removal of solid material from the surface by rubbing action
Wear Resistance
121
It is a form of magnetism in which unpaired electron spins align parallel to one another
Ferromagnetism
122
Property of a metal by virtue of which it can be drawn into wires
Ductility
123
Property of a metal that deals with its capacity to be rolled, drawn, casted, hardened, heated, and recrystaized without any permanent deformation or change in its properties
Workability/Formability
124
The ability of a material to withstand bending or tension without fracture
Toughness
125
It is an important basis for fixing the working stresses especially in the case of brittle materials. Its unit is kg/cm^2
Tensile Strength
126
The ability of a metal to withstand sudden and severe changes in temperature without failure
Thermal Shock Resistance
127
It increases the fatigue resistance of a material
Annealing
128
The resistance of a material to plastic deformation by indentation
Hardness
129
Complex property of a metal or alloy which allows it when molten, to fill a mould and give a flawless casting
Castability
130
It is the ability of a metal to be machined by a gicen tool with little energy ay high speed without unduly reducing the life of the tool and resulting in a finished smooth surface
Machinability
131
An alloy is a _____ ______ of two or more elements with metallic properties or a metal and a non-metal possessing metallic properties
Homogenous mixture
132
It is the phenomenon that leads to fracture under conditions where materials are subjected to repeated loads or stresses
Fatigue
133
Ability of a material to return to its original form when the stretching, bending, or compressing force is removed
Resilience
134
It is the property which enables a material to overcome fatigue
Fatigue resistance
135
Indictive of a material’s ability to absorb heat from the surroundings
Heat Capacity/Specific Heat
136
The property by virtue of which a metal can be beaten into sheets by hammering or rolling
Malleability
137
What is the most malleable metal?
Gold
138
Give an example of a brittle material
Glass
139
The change in dimension of a metal in response to thermal energy and is measured in terms of coefficient of ______ _______
Thermal Expansion
140
It is the reverse of elasticity
Plasticity
141
The process of heating a steel to a high temperature and then cooling it carefully under controlled conditions
Annealing
142
Property of a material by virtue of which it may be permanently deformed when subjected to an external force great enough to exceed the elastic limit
Plasticity
143
What are the two common ferrous alloys?
Steel and Cast Iron
144
These alloys contain iron as one of their major components
Ferrous Alloys
145
The carbon content in steel is noy more than how many percent?
1.3%
146
How many percent of carbon can cast iron contain?
1.7% - 4.0%
147
It is a process involving a sequence of heating and cooling operations in steel (or any other metal alloy) to obtain a desired combination of properties.
Heat Treatment
148
Heat Treatment produces the following effects in the properties of metals except
A. Improves machinability
B. Improves electrical, thermal, and magnetic properties of the metal
C. Relieves the metal of external stresses
D. Refines grain size and make the metal structure homogenous
E. Improves ductility, toughness, resistance of material to heat, wear, shock, and corrosion
C, Heat Treatment relieves INTERNAL stresses of metal
149
It is also known as air quenching
Normalizing
150
It is a rapid cooling of steel by immersing it in a liquid bath such as water or oil
Hardening of Steel
151
In this process, the quenched steel is reheated to a predetermined temperature
Tempering
152
Trivia: The following ate the purpose of normalizing:
A. To produce a uniform structure
B. Refine grain size of steel
C. Reduce internal stress
D. Produce harder and stronger steel than full annealing
E. Improve the engineering properties of steel
153
It is a stressed conditiond and hence it is very brittle. It cannot be used for practical purposes
Hardened Steel
154
Trivia: Hardening is followed by Tempering
155
It involves heating of steel to 40-50 degrees Celsius
Normalizing
156
It is faster than furnace cooling
Air cooling
157
It reduces stress and strains that developed due to quenching. It is always applied to cutting tools like blades, chisels, cutters, and tool bits
Tempering
158
For better toughness, the tempering temperature should not exceed to how many degrees Celsius?
400 degrees Celsius
159
In hardening of steel, steel is heated to how many degrees above the upper critical temperature?
30-50 degrees Celsius
160
At how many degrees is carbon steel reheated?
200 degrees Celsius
161
At how many degrees is steel containing 0.35 - 3.5% carbon reheated?
400 - 650 degrees Celsius
