Task1
1Body centred cubic (BCC):(tungsten)
The Body-Centered Cubic (BCC) crystal structure is one of the most common
ways for atoms to arrange themselves in metals. The BCC crystal structure is
based on the Bravais lattice of the same name, with 1 atom per lattice point at
each corner of the cube and the center of the cube.
Face centred cubic (FCC):(copper)
It is cubic unit cell in which atoms located at each of the corners and the centers
of all the cube faces
Some of the familiar metals having this crystal structure are copper, aluminum,
silver, and gold.
Hexagonal close packed (HCP):(zinc)
Hexagonal close packing structure consists of alternating layers of spheres or
atoms arranged in a hexagon, with one additional atom at the centre.
Number of atoms
Coordination Number
FCC
14
12
BCC
9
8
HCP
17
12
2Amorphous
Crystalline Polymers
Amorphous polymers are polymers Crystalline polymers are polymers that
that have no ordered pattern in its have a well-organized structure.
molecular structure.
Morphology
Amorphous polymers are made out of Crystalline polymers are made out of
atactic polymer chains.
syndiotactic and isotactic polymer
chains.
Attraction Forces
Amorphous polymers have weak Crystalline polymers have strong
attraction forces between polymer attraction forces between polymer
chains.
chains.
Density
Amorphous polymers have a low Crystalline polymers have a high
density.
density.
Chemical Resistance
Amorphous polymers have a low Crystalline polymers have a high
chemical resistance.
chemical resistance.
Polymer Chains
Polymer chains are arranged in an Polymer chains are arranged in a
atactic
manner
in
amorphous syndiotactic and isotactic manner in
polymers.
crystalline polymers.
Appearance
Amorphous polymers are transparent.
Crystalline polymers are translucent
Difference Between Thermoplastic and Thermosetting Plastic
Thermoplastic
Thermoplastic can be synthesized by the
process called addition polymerization.
Thermoplastic is processed by injection
moulding, extrusion process, blow
moulding, thermoforming process, and
rotational moulding.
Thermoplastics have secondary bonds
between molecular chains.
Thermoplastics have low melting points
and low tensile strength.
Thermoplastic is lower in molecular
weight, compared to thermosetting
plastic.
Examples
Polystyrene
Teflon
Acrylic
Nylon
Thermosetting Plastic
Thermosetting plastics are synthesized by
condensation polymerization.
Thermosetting Plastic is processed by
compression moulding, reaction injection
moulding.
Thermosetting plastics have primary
bonds between molecular chains and
held together by strong cross-links.
Thermosetting plastics have high melting
points and tensile strength.
Thermosetting Plastic is high in molecular
weight.
Examples
Vulcanized rubber
Bakelite
Polyurethane
Epoxy resin
Vinyl ester resin
3- (a)
 )Aluminium(
Mechanical Properties of Aluminium
Aluminium can be severely
deformed without failure. This
allows aluminium to be formed
by rolling, extruding, drawing,
machining and other mechanical
processes. It can also be cast to
a high tolerance.
Alloying, cold working and heattreating can all be utilised to
tailor the properties of
aluminium.
The tensile strength of pure
aluminium is around 90 MPa but
this can be increased to over
690 MPa for some heat-treatable alloys.
 Elasticity in tension:Aluminum has a Young’s modulus of 10000 ksi. Compare this to
copper at 17550 ksi or wood at 1595 ksi.
 Tensile strength ultimate: 13,000 Psi
 Yield strength: 5,000 Psi
 Bearing yield strength:23100 Psi
 Elongation at break: 15-28%
 Shear Strength: 9000 Psi
 Fatigue strength: 5000 Psi
Thermal Properties of Aluminium
Thermal properties of materials refer to the response of materials to changes in their
temperature and to the application of heat.
 Melting Point of Aluminium
Melting point of 2024 aluminium alloy is around 570°C.
Melting point of 6061 aluminium alloy is around 600°C.
In general, melting is a phase change of a substance from the solid to the liquid phase.
 Thermal Conductivity of Aluminium Alloys
‫ذ‬The thermal conductivity of 2024 aluminium alloy is 140 W/(m.K).
The thermal conductivity of 6061 aluminium alloy is 150 W/(m.K).
Electrical Properties of Aluminium
 Electrical Conductivity
Pure aluminum and some of its alloys have very high electrical conductivity (low electrical
resistance), second only to metals including copper, which are used as electricity
conductors.
Physical Properties of Aluminium
 Aluminium has a lower density than any other commercial metal except magnesium.
Given the right type of surface, aluminium makes an excellent reflector, especially for
ultraviolet light.
 Aluminium is an odourless, tasteless, silvery-white metal. With increasing silicon and
ductile and quite soft. The aluminium crystal has a face-centred cubic structure.
 The concentration of the lattice in the less pure metal results from the formation of
impurity segregations. Purity also affects most other physical properties.
 Aluminium has a lower density than any other commercial metal except magnesium.
 (Copper)
Mechanical Properties of Copper
The primary mechanical
properties of copper—hardness,
strength and ductility—
determine its condition. The
material condition (alternative
term: temper) is designated in
standards either by the letter H,
representing a minimum
hardness, or the letter R,
representing a minimum tensile
strength.
 Copper is known for being a
good conductor of heat and
electricity.
 It takes place inside the solid
lattice of metals because the delocalized electrons have the freedom to move freely in
their lattice.
 Copper acts as the transporters of electric charge and heat. It transports from one end
to the other.
 It turns metals into good conductors.
The thermal conductivity tends to decrease with the increase of temperature because of the
blockage of the movement of free electrons which is due to the kernel of metal ions with
high vibration temperature.

Electrical Properties of copper
As copper is highly conductive, the measurement of the materials electrical resistivity can
get challenging. As the voltage drop along the sample is small for this material, a flexible
measurement configuration in terms of geometry (long and thin samples are preferred) and
measurement current (maximum measurement current should be large) are important.
Physical properties of copper
ELECTRICAL CONDUCTIVITY
The generation, transmission and use of electricity has transformed the modern world. This
has been made possible by copper (of at least 99.9% purity), which has the best electrical
conductivity of any common metal – one of the more well- known physical properties of
copper. It is available in wrought form as wire, cable,strip and busbars and as castings for
such components as electrical switchgear andwelding equipment.
THERMAL CONDUCTIVITY
Copper is a good conductor of heat (about30 times better than stainless steel and 1.5 times
better than aluminium).
EASE OF JOINING
Copper can be readily jo soldering, bolting or adhe
this is very useful for pl and joining busbars, w elements of power dist Elsewhere, it is also
an for artists crafting sculpt and for jewellery makers a working with this beautiful
 (Stainless steel)
Mechanical Properties of Stainless steel
Corrosion
The addition of nitrogen also improves resistance to pitting corrosion and increases
mechanical strength. Thus, there are numerous grades of stainless steel with varying
chromium and molybdenum contents to suit the environment the alloy must endure.
Wear
Galling, sometimes called cold welding, is a form of severe adhesive wear, which can occur
when two metal surfaces are in relative motion to each other and under heavy pressure.
Thermal Properties of Stainless steel
Melting point
As with all other alloys, the melting point of stainless steel is expressed in the form of a
range of temperatures, and not a singular temperature. This temperature range goes from
1,400 to 1,530 °C (2,550 to 2,790 °F) depending on the specific consistency of the alloy in
question
Electrical Properties of Stainless steel
Conductivity
Like steel, stainless steels are relatively poor conductors of electricity, with significantly
lower electrical conductivities than copper. In particular, the electrical contact resistance
(ECR) of stainless steel arises as a result of the dense protective oxide layer and limits its
functionality in applications as electrical connectors.
Physical properties of Stainless steel
Density
The density of stainless steel can be
somewhere between 7,500kg/m3 to
8,000kg/m3 depending on the alloy.
 (medium carbon steel)
Mechanical Properties of medium
carbon steel
Materials are frequently chosen for various
applications because they have desirable
combinations of mechanical characteristics.
For structural applications, material
properties are crucial and engineers must take
them into account.
Strength of Medium-carbon Steel
In mechanics of materials, the strength of a
material is its ability to withstand an applied
load without failure or plastic deformation.
Ultimate Tensile Strength
Ultimate tensile strength of medium-carbon
steel is 620 MPa.
Yield Strength - Ultimate Tensile Strength Table of MaterialsThe ultimate tensile
strength is the maximum on the engineering
stress-strain curve.
Yield Strength
Yield strength of medium-carbon steel is 420 MPa.
The yield point is the point on a stress-strain curve that indicates the limit of elastic
behavior and the beginning plastic behavior.
Young’s Modulus of Elasticity
Young’s modulus of elasticity of medium-carbon steel is 200 GPa.
The Young’s modulus of elasticity is the elastic modulus for tensile and compressive stress
in the linear elasticity regime of a uniaxial deformation and is usually assessed by tensile
tests.
Hardness of Medium-carbon Steel
Brinell hardness of medium-carbon steel is approximately 200 MPa.
Brinell hardness number In materials science, hardness is the ability to withstand surface
indentation (localized plastic deformation) and scratching.
Thermal Properties of medium carbon steel
Thermal properties of materials refer to the response of materials to changes in their
temperature and to the application of heat.
Melting Point of Medium-carbon Steel
Melting point of medium-carbon steel is around 1520°C.
In general, melting is a phase change of a substance from the solid to the liquid phase.
Thermal Conductivity of Medium-carbon Steel
The thermal conductivity of medium-carbon steel is 50 W/(m.K).
The heat transfer characteristics of a solid material are measured by a property called the
thermal conductivity, k (or λ), measured in W/m.K.
 (plastic)
Thermoplastics and thermosetting polymers
This plastic handle from a kitchen utensil has been deformed by heat and partially melted
One important classification of plastics is the degree to which the chemical processes used
to make them are reversible or not.
Amorphous plastics and crystalline plastics
Many plastics are completely amorphous (without a highly ordered molecular
structure),[15] including thermosets, polystyrene, and methyl methacrylate (PMMA).
Conductive polymers
Intrinsically Conducting Polymers (ICP) are organic polymers that conduct electricity. While
a conductivity of up to 80 kS/cm in stretch-oriented polyacetylene,has been achieved, it does
not approach that of most metals. For example, copper has a conductivity of several hundred
kS/cm.[
(b)
Hardness
Material
Results hardness
Type
Value of hardness
Aluminum
127
139 6070
137
Copper
142.71
143.71 (C19720)
120-150
Stainless steel
136.68
146.17 NAS 310S
134
Medium Carbon Steel 178.90
166.44 AISI 1030 Steel
178
Plastic
71.88
66.58 HDPE
67
There were no differences between the global results and the results calculated in the
laboratory.
The results extracted from the laboratory are similar to the internationally recognized
figures.
(c)
Material
Aluminum
Copper
Stainless steel
Medium Carbon Steel
Application 1
Lamp cap stock
litter bins
Culinary uses
gears
Application 2
connectors
Plastic
Chair
bottles
door pulls
Kitchen sinks
crankshafts
(d)
(connectors(Al-6066
Al-6066 can be tailored to have superior properties such as high stiffness and higher specific
strength, enhanced high temperature performance, lower thermal expansion co-efficient, and
increased wear resistance.
(Kitchen sinks) NAS 310S
The alloy stainless steel is very rust resistant.
(litter bins) C 19720
It increases the hardness and strength of the metal
(Gears) AISI 1030 Steel
The hardness values, impact strengths and tensile strengths of the
austempered samples increased almost linearly
4-Types of preventive maintenance for a bump
There are 4 major types of preventive maintenance. Each is built around the concept of
planned maintenance, although they are all organized and scheduled differently, to suit
different business operation purposes.
i. Usage-based preventive maintenance
Usage-based preventive maintenance is triggered by the actual utilization of an asset. This
type of maintenance takes into account the average daily usage or exposure to
environmental conditions of an asset and uses it to forecast a due date for a future
inspection or maintenance task.
ii. Calendar/time-based preventive maintenance
Calendar/time-based preventive maintenance occurs at a scheduled time, based on a
calendar interval. The maintenance action is triggered when the due date approaches and
necessary work orders have been created.
iii. Predictive maintenance
Predictive maintenance is designed to schedule corrective maintenance actions before a
failure occurs. The team needs to first determine the condition of the equipment in order
to estimate when maintenance should be performed. Then maintenance tasks are
scheduled to prevent unexpected equipment failures.
iv. Prescriptive maintenance
Prescriptive maintenance doesn’t just show that failure is going to happen and when, but
also why it’s happening.
Task2
1-
Parts
laminated windscreen
Materials
Laminated Glass
Seats
Shell
Leatherette (Faux Leather), Alcantara
(Ultrasuede) , Nylon,PVC and Leather
steel
tyres
rubber
bumper
Plastics HDPE
Engine block
cast iron or an aluminium alloy
2Materials
Aluminum
Parts
engine radiators, wheels, bumpers,
suspension parts, engine cylinder blocks,
transmission bodies and body parts: the
hoods, the doors and even the frame
Copper
car radiator
Stainless steel
car exhaust systems,hose clamps and seat
belt springs
Medium Carbon Steel
crankshafts and equipping plates
Plastic
Bumper,wheel arches,engine splash
shields,grilles,floor rails,and door panels.
3-
Specific characteristics of Aluminum
It has low density, is non-toxic, has a high thermal conductivity, has excellent corrosion
resistance and can be easily cast, machined and formed. It is also non-magnetic and nonsparking. It is the second most malleable metal and the sixth most ductile.
Specific characteristics of Copper
Copper is a reddish metal with a face-centered cubic crystalline structure. It reflects red and
orange light and absorbs other frequencies in the visible spectrum, due to its band
structure, so it as a nice reddish color. It is malleable, ductile, and an extremely good
conductor of both heat and electricity.
Specific characteristics of Stainless steel



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


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Corrosion resistant.
High tensile strength.
Very durable.
Temperature resistant.
Easy formability and fabrication.
Low-maintenance (long lasting)
Attractive appearance.
Environmentally friendly (recyclable)
Specific characteristics of Medium Carbon Steel
The medium-carbon steels have carbon content of 0.30% to 0.60%. They may contain
manganese ranging from 0.6% to 1.65%
Specific characteristics of plastic






They are light in weight and are chemically stable.
Easily moulded into different shapes and sizes.
Good insulation and low thermal conductivity.
Good impact resistance and they do not rust.
Good transparency and wear resistance.
Poor dimensional stability and can be easily deformed.
4-Explain why the behavior of materials is considered such an
important factor when selecting a material for a given product or
application









Performance requirements
Reliability requirements
Size, shape, and mass requirements
Cost requirements
Manufacturing and assembly requirements
Industry standards
Government regulations
Intellectual property requirements
Sustainability requirements
5-Fe-Fe3C phase diagram
(b) Hypoeutectoid steel: Steel containing < 0.8 % C
(c) Hypereutectoid steel: Steel containing > 0.8 % C (up to 2 % C)
6Calculate the amounts and compositions of phases and microconstituents in a
Fe-0.60% C alloy at 726 C.
The phases are ferrite a cementite. Using a tie line and working
the lever law at 726 C, we find:
6.67 − 0.60
 α(0.0218%C)%α = [6.67
− 0.0218
]×100 = 91.3%
0.60 − 0.0218
]×100
− 0.0218
 Fe3C(6.67%C)%Fe3C =[6.67
= 8.7%
7-
8-
do=13.8mm
du=11.7mm
Percent reduction in area=(do-du)/do *100=(13.8-11.7)/13.8 *100=15.72%
9-
Task 3
1-
 HOMOGENIZING
The initial thermal operation applied to ingots prior to hot working is referred to as "ingot
preheating", which has one or more purposes depending upon the alloy, product, and
fabricating process involved.
 A
N
N
E
A
L
I
N
G
The distorted, dislocated structure resulting from cold working of aluminum is less stable
than the str
ain-free, annealed state, to which it tends to revert. Lower-purity aluminum and
commercial aluminum alloys undergo these structural changes only with annealing at
elevated temperatures.
Recovery. The reduction in the number of dislocations is greatest at the center of the grain
fragments, producing a subgrain structure with networks or groups of dislocations at the
subgrain boundaries.
Recrystallization is characterized by the gradual formation and appearance of a
microscopically resolvable grain structure.
Grain Growth After Recrystallization. Heating after recrystallization may produce grain
coarsening. This can take one of several forms.
 PRECIPITATION HARDENING
General Principles of Precipitation Hardening. The heat treatable alloys contain amounts
of soluble alloying elements that exceed the equilibrium solid solubility limit at room and
moderately higher temperatures.
Nature of Precipitates and Sources of Hardening. Intensive research during the past forty
years has resulted in a progressive accumulation of knowledge concerning the atomic and
crystallographic structural changes that occur in supersaturated solid solutions during
precipitation and the mechanisms through which the structures form and alter alloy
properties.
Kinetics of Solution and Precipitation. The relative rates at which solution and precipitation
reactions occur with different solutes depend upon the respective diffusion rates, in
addition to solubilities and alloy contents.
Nucleation. The formation of zones can occur in an essentially continuous crystal lattice by
a process of homogeneous nucleation. Recent investigations provide evidence that a critical
vacancy concentration is required for this process and that a nucleation model involving
vacancy-solute atom clusters is consistent with certain effects of solution temperature and
quenching rate.
 Quenching
Quenching is in many ways the most critical step in the sequence of heat treating
operations. The objective of quenching is to preserve as nearly intact as possible the solid
solution formed at the solution heat treating temperature, by rapidly cooling to some lower
temperature, usually near room temperature.
Critical Temperature Range. The fundamentals involved in quenching precipitationhardenable alloys are based on nucleation theory applied to diffusion-controlled solid state
reactions. The effects of temperature on the kinetics of isothermal precipitation depend
principally upon degree of supersaturation and rate of diffusion.
Quenching Medium. Water is not only the most widely used quenching medium but also
the most effective. It is apparent that in immersion quenching, cooling rates can be reduced
by increasing water temperature. Conditions that increase the stability of a vapor film
around the part decrease the cooling rate; various additions to water that lower surface
tension have the same effect.
2- MATERIALS TESTING
Hardness test
Hardness is the ability to withstand indentation or scratches.The application of hardness
testing enables you to evaluate a material’s properties, such as strength, ductility and wear
resistance, and so helps you determine whether a material or material treatment is suitable
for the purpose you require.
Impact Tests
An impact test is used to observe the mechanics that a material will exhibit when it
experiences a shock loading that causes the specimen to immediately deform, fracture or
rupture completely.
Tensile Testing
 Uses an extensometer to apply measured
force to an test specimen. The amount of
extension can be measured and graphed.
 Variables such as strain, stress, elasticity,
tensile strength, ductility and shear
strength
can be gauged.
 Test specimens can be round or flat.
Compression Testing
Compressive testing shows how the material will react when it is being compressed.
Compression testing is able to determine the material's behavior or response under
crushing loads and to measure the plastic flow behavior and ductile fracture limits of a
material.
Torsion Test
Torsion testing involves the twisting of a sample along an axis and is a useful test for
acquiring information like torsional shear stress, maximum torque, shear modulus, and
breaking angle of a material or the interface between two materials
Fracture toughness testing
The Fracture Toughness Test determines how well a material can resist the growth of a
crack under an increasing load. The fracture toughness values identified by the test are
useful in material selection and in determining whether there is a danger of component
failure when a flaw is discovered in an existing structure.
3WHY IS MATERIALS TESTING PERFORMED?
Tensile testing Materials Testing is performed for a variety of reasons and can provide a
wealth of information about the tested materials, prototypes or product samples. The data
collected during testing and the final test results can be very useful to engineers, designers,
production managers and others.
 Meeting requirements of regulatory agencies
 Selecting appropriate materials and treatments for an application
 Evaluating product design or improvement specifications
 Verifying a production process
5Brittle fracture
Fracture is the separation of an object or material into two or more pieces under the action
of stress. The fracture of a solid usually occurs due to the development of certain
displacement discontinuity surfaces within the solid. If a displacement develops
perpendicular to the surface, it is called a normal tensile crack or simply a crack; if a
displacement develops tangentially, it is called a shear crack, slip band or dislocation.
Impact
An impact is a high force or shock applied over a short time period when two or more
bodies collide. Such a force or acceleration usually has a greater effect than a lower force
applied over a proportionally longer period. The effect depends critically on the relative
velocity of the bodies to one another.
Creep failure
Creep failure is the time-dependent and permanent deformation of a material when
subjected to a constant load or stress. This deformation typically occurs at elevated
temperatures, although it may occur under ambient temperatures as well.
Thermal shock
Thermal shock is a type of rapidly transient mechanical load. By definition, it is a mechanical
load caused by a rapid change of temperature of a certain point. It can be also extended to
the case of a thermal gradient, which makes different parts of an object expand by different
amounts. This differential expansion can be more directly understood in terms of strain,
than in terms of stress, as it is shown in the following. At some point, this stress can exceed
the tensile strength of the material, causing a crack to form. If nothing stops this crack from
propagating through the material, it will cause the object's structure to fail.
Wear
Wear is the damaging, gradual removal or deformation of material at solid surfaces. Causes
of wear can be mechanical (e.g., erosion) or chemical (e.g., corrosion). The study of wear
and related processes is referred to as trichology.
Buckling
buckling is the sudden change in shape (deformation) of a structural component under load,
such as the bowing of a column under compression or the wrinkling of a plate under shear.
If a structure is subjected to a gradually increasing load, when the load reaches a critical
level, a member may suddenly change shape and the structure and component is said to
have buckled.[2] Euler's critical load and Johnson's parabolic formula are used to determine
the buckling stress in slender columns.
6,7Non-destructive testing processes
Non-destructive testing (NDT) is a testing and analysis technique used by industry to
evaluate the properties of a material, component, structure or system for characteristic
differences or welding defects and discontinuities without causing damage to the original
part. NDT also known as non-destructive examination (NDE), non-destructive inspection
(NDI) and non-destructive evaluation (NDE).
Dye Penetrant
Penetrant Non-Destructive Testing (also called Liquid Penetrant Testing) refers to the
process of using a liquid to coat a material and then looking for breaks in the liquid to
identify imperfections in the material.
Magnetic Particle
Magnetic Particle Non-Destructive Testing is the act of identifying imperfections in a
material by examining disruptions in the flow of the magnetic field within the material.
Ultrasonic
Ultrasonic Non-Destructive Testing is the process of transmitting high-frequency sound
waves into a material in order to identify changes in the material’s properties.
Ra
di
og
ra
ph
y
Radiography Non-Destructive Testing is the act of using gamma- or X-radiation on materials
to identify imperfections.
8-Describe working and environmental conditions that lead to failure for a
product made from material

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Extreme temperatures – these products provide effective insulation against extreme
heat and cold. Common applications include military vehicles and machinery, paving
or plowing machines, construction and drilling equipment, outdoor/survival gear and
laboratory equipment.
Oil and chemicals – sealing solutions can protect machinery against spills and leaks
from oil and chemicals. Common applications include elevators, HVAC systems and
security systems, as well as scientific and agricultural instruments to prevent
exposure to contaminants like fertilizers, inclement weather and manure.
Food, beverages, and other fluids – everyone gets hungry and thirsty at some point
during the day, but APM products help prevent even the stickiest or greasiest lunches
from interfering with equipment’s performance.
Water and weather – keeping water from seeping into equipment can be challenging,
but our products are used in applications as diverse as electrical panels, marine and
boating equipment, outdoor construction equipment and train steering systems.
Road salt – no one likes a slick road in the winter, but sometimes the salts used to
increase traction on the road can be even more damaging to vehicles and equipment
over time. APM products can help protect cars and construction and utility vehicles
from salt corrosion.
Air – preventing air from leaking out and causing a loss of pressure is especially
important in applications such as pressure gauges and testing equipment.
Dirt, dust, and sand – keeping sediments out of your equipment is critical to
maintaining its overall health. For mechanical equipment used outdoors such as
construction machinery or military equipment used in harsh environments like
deserts, sealing solutions can keep a number of applications free from dust, dirt, sand,
sawdust, and other particles.
9 Preventive Maintenance
This type, preventive maintenance, seeks out and repairs more minor issues and decreases
the occurrence of major repairs. Preventive maintenance may take on aspects of all other
maintenance types.
For example, maintenance inspections may change based on the age of the equipment. When
it is new, the procedure may be more of a predetermined maintenance style, but as it ages,
more frequent inspections, both physical and through data, may prevent more minor
performance issues from becoming extensive and more costly repairs.
Example of Preventative Maintenance
An excellent example of preventative maintenance is the seasonal cleaning of an HVAC unit.
In spring, you schedule maintenance to ensure that grit and sand are not inside the casing or
leaves are not blocking the air intake in the fall. There is no specific issue, but we know that
leaves can accumulate and cause problems later in the fall. Removing the grit or leaves now
prevents a later difficulty, such as poor performance, increased energy usage, etc.
Preventive maintenance is easily described as regular and routine inspections that look for
wear before symptoms appear.
Benefits of Preventative Maintenance
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Prevention of major repairs.
Keeps businesses open by preventing most emergency repairs.
Adds to the product’s lifecycle by reducing wear.
Keeps energy costs at their lowest possible rates.
 Corrective Maintenance
Maintenance teams activate after the uncovering of a problem. The goal of corrective
maintenance is to bring systems back to regular operation as quickly as possible. With
corrective maintenance, there is no program for regular maintenance. A problem must be
present before maintenance occurs.
Examples of corrective maintenance include:
Repairing a broken HVAC unit rather than maintaining it.
Repairing an HVAC unit after data from the unit shows it is not functioning at peak
performance.
Benefits of Corrective Maintenance
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Decreased monthly maintenance costs.
Decrease in time for managing maintenance.
Focuses on non-critical elements.
A more straightforward maintenance process.
 Redetermined Maintenance
Predetermined maintenance follows a plan of action created by the manufacture of
equipment, rather than scheduled maintenance laid out by a maintenance team.
Examples of Predetermined Maintenance
An excellent example of predetermined maintenance is when machinery maintenance is
scheduled at time intervals based on the manufacture’s recommendations. For example, oil
changes will be every fourth month. Transmission service will occur at X number of hours of
run time. After one year of use, Parts X, Y, and Z are checked for wear. Engine replacement
occurs after X number of years.
Even if the machine has sat idle for four months, the oil is changed. The list of maintenance
is scheduled based on time or usage rather than functionality.
Another example is when smart data indicates a decrease in productivity. The drop in
performance signals a need for maintenance.
Predetermined Maintenance Benefits
 Much easier to schedule and manage, including labor.
 The manufacturer outlines the maintenance plan.
 You can schedule technicians rather than hire maintenance personnel.
 Condition-Based Maintenance
As the name implies, condition-based maintenance focuses on outcomes through
measurement or observation. Machines have a range of normal operating conditions. Within
that range, the operation is acceptable. Near the edges of that range, maintenance may be
required.
Examples of Condition-Based Maintenance
An excellent example of condition-based maintenance is that pesky check engine light in
your car. When it comes to the car’s system has indicated that something is out of the normal
range and maintenance is scheduled. The exact process may occur with machines that selfmonitor through smart technology or physical inspections in a business.
Another example of condition-based maintenance might be when a machine begins to use
more energy to function. That may be that a tank of fuel does not last as long or that there is
a sudden spike in electrical usage. Again, that level of condition requires maintenance.
10-Explain the methods that could be used for estimating product service life
when a product is subject to creep and fatigue loading.
Creep-fatigue life prediction method using Diercks equation for Cr-Mo steel
for dealing with the situation that creep-fatigue life properties of materials do not exist, a
development of the simple method to predict creep-fatigue life properties is necessary.
 Evaluation of creep-fatigue life prediction methods for low-carbon/nitrogen-added
SUS316
Low-carbon/medium nitrogen 316 stainless steel called 316FR is a principal candidate for
the high-temperature structural materials of a demonstration fast reactor plan.
 Prediction of creep-fatigue life by use of creep rupture ductility
It was clarified that tension strain hold reduced creep-fatigue life of many engineering
materials in different degrees depending on material, temperature and test duration.
 Influences of cyclic deformation on creep property and creep-fatigue life prediction
considering them
Evaluation of creep-fatigue is essential in design and life management of high-temperature
components in power generation plants.
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