Chapter 1: Introduction to Materials Science and Engineering
1-1 Define materials science and engineering (MSE).
Solution:
Materials science and engineering (MSE) is an interdisciplinary field that studies
and manipulates the composition and structure of materials across length scales to
control materials properties through synthesis and processing.
1-2 What is the importance of the engineering tetrahedron for materials engineers?
Solution:
Structure, properties and performance all depend on the route in which a material is
processed. We cannot predict the end properties for a material until we have
specified a process to produce the component. Using the same material, but changing
the way it is processed will result in different structure, properties and performance
of that material. This is applicable to all material systems.
1-3 Define the following
terms:
(a) composition;
(b) structure;
(c) synthesis;
(d) processing; and
(e) microstructure.
Solution:
(a) The chemical make-up of a material.
(b) The arrangement of atoms, seen at different levels of detail.
(c) How materials are made from naturally occurring or man-made chemicals.
(d) How materials are shaped into useful components.
(e) The structure of an object at the microscopic scale.
1-4 Explain the difference between the terms materials science and materials engineering.
Solution:
Materials scientists work on understanding underlying relationships between the
synthesis and processing, structure, and properties of materials. Materials
engineers focus on how to translate or transform materials into useful devices or
structures.
, 1
© 2016 Cengage Learning. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or
in part.
,1-5 The myriad materials in the world primarily fall into four basic categories; what
are they? What are materials called that have one or more different types of
material fabricated into one component? Give one example.
Solution:
Metals, polymers and ceramics. The addition of one or more of these to a single
system is called a composite. An example of a composite material is fiberglass.
1-6 What are some of the materials and mechanical properties of metals and alloys?
Solution:
Metals and alloys have good electrical and thermal conductivity, high strength,
ductility and formability, and high stiffness.
1-7 What is a ceramic, and what are some of the properties that you expect from a ceramic?
Solution:
Ceramics tend to have very high compressive strengths, but behave in a brittle
(glass-like) manner. They have very high melting temperatures. Poor thermal
conductivity and electrical conductivity make ceramics behave as an insulator
instead of a conductor.
1-8 Make comparisons between thermoplastics and thermosetting polymers (a) on the
basis of mechanical characteristics upon heating, and (b) according to possible molecular
structures.
Solution:
Thermoplastics tend to soften with elevated temperature exposure with gradually
decreasing viscosity. Thermosetting polymers do not soften with elevated
temperature exposure; instead they will remain hard and will degrade, possibly
charring with prolonged exposure.
Thermoplastics consist of long chain molecular arrangements of covalently bonded
carbon atoms with various side groups. Thermosetting polymers tend to be a
complex 3-D arrangement usually deviating from the clearly defined long-chain
molecular
arrangement.
1-9 Give three examples of composites that can be fabricated.
Solution:
Metal matrix composites (MMC) – A metal matrix reinforced with a ceramic material
in the form of particles, whiskers or fibers. Example: Cobalt alloy reinforced with
tungsten-carbide particulates.
Polymer matrix composites (PMC) – A polymer matrix reinforced with a
ceramic material in the form of whiskers or fibers. Example: Kevlar or
fiberglass.
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© 2016 Cengage Learning. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or
in part.
1-1 Define materials science and engineering (MSE).
Solution:
Materials science and engineering (MSE) is an interdisciplinary field that studies
and manipulates the composition and structure of materials across length scales to
control materials properties through synthesis and processing.
1-2 What is the importance of the engineering tetrahedron for materials engineers?
Solution:
Structure, properties and performance all depend on the route in which a material is
processed. We cannot predict the end properties for a material until we have
specified a process to produce the component. Using the same material, but changing
the way it is processed will result in different structure, properties and performance
of that material. This is applicable to all material systems.
1-3 Define the following
terms:
(a) composition;
(b) structure;
(c) synthesis;
(d) processing; and
(e) microstructure.
Solution:
(a) The chemical make-up of a material.
(b) The arrangement of atoms, seen at different levels of detail.
(c) How materials are made from naturally occurring or man-made chemicals.
(d) How materials are shaped into useful components.
(e) The structure of an object at the microscopic scale.
1-4 Explain the difference between the terms materials science and materials engineering.
Solution:
Materials scientists work on understanding underlying relationships between the
synthesis and processing, structure, and properties of materials. Materials
engineers focus on how to translate or transform materials into useful devices or
structures.
, 1
© 2016 Cengage Learning. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or
in part.
,1-5 The myriad materials in the world primarily fall into four basic categories; what
are they? What are materials called that have one or more different types of
material fabricated into one component? Give one example.
Solution:
Metals, polymers and ceramics. The addition of one or more of these to a single
system is called a composite. An example of a composite material is fiberglass.
1-6 What are some of the materials and mechanical properties of metals and alloys?
Solution:
Metals and alloys have good electrical and thermal conductivity, high strength,
ductility and formability, and high stiffness.
1-7 What is a ceramic, and what are some of the properties that you expect from a ceramic?
Solution:
Ceramics tend to have very high compressive strengths, but behave in a brittle
(glass-like) manner. They have very high melting temperatures. Poor thermal
conductivity and electrical conductivity make ceramics behave as an insulator
instead of a conductor.
1-8 Make comparisons between thermoplastics and thermosetting polymers (a) on the
basis of mechanical characteristics upon heating, and (b) according to possible molecular
structures.
Solution:
Thermoplastics tend to soften with elevated temperature exposure with gradually
decreasing viscosity. Thermosetting polymers do not soften with elevated
temperature exposure; instead they will remain hard and will degrade, possibly
charring with prolonged exposure.
Thermoplastics consist of long chain molecular arrangements of covalently bonded
carbon atoms with various side groups. Thermosetting polymers tend to be a
complex 3-D arrangement usually deviating from the clearly defined long-chain
molecular
arrangement.
1-9 Give three examples of composites that can be fabricated.
Solution:
Metal matrix composites (MMC) – A metal matrix reinforced with a ceramic material
in the form of particles, whiskers or fibers. Example: Cobalt alloy reinforced with
tungsten-carbide particulates.
Polymer matrix composites (PMC) – A polymer matrix reinforced with a
ceramic material in the form of whiskers or fibers. Example: Kevlar or
fiberglass.
, 2
© 2016 Cengage Learning. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or
in part.
