Introduction to Materials
Technology
Text Chapter 1
Charles W. Smith, PhD
Department of Construction Management
Colorado State University
Fort Collins, Co
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• Elements…Molecules of same types of atoms; cannot be
broken down into chemically simpler substances…Periodic
Chart
• Metals:
generally solid at room temperature
-Tend to be good conductors.
• Nonmetals:
may be solids, liquids, or gases
at room temp.
-Tend to be good insulators
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Compounds…Molecules of different types of
atoms…may have properties substantially different
from the constituent elements…
- salt- NaCl: sodium and chlorine, water- H2O:
Hydrogen and Oxygen. (molecularly bonded)
• Alloys: metals combined with one or more other
elements
- Steel alloys, copper alloys, aluminum alloys and others
•
a mixture containing two or more metallic elements or metallic and nonmetallic elements
usually fused together or dissolving into each other when molten; "brass is an alloy of
zinc and copper"
• Mixtures…mechanically mixed together, but still
chemically separate…the mixed substances may be
elements or compounds…oil and water, smoke in air,
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muddy water.
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Materials can be:
• Natural vs. Manufactured
Elements can be either Naturally occurring or can be
Synthetically manufactured.
• Organic vs. Inorganic
Compounds can be either Organic or Inorganic
(Organic compounds contain carbon)
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Bonding of Materials
• Material properties are affected by ability to combine/react with other
materials, which is related to the chemical structure, especially
electrons in the outer shell (valence electrons)
• Types of bonding
• Ionic: In compounds, where one atom gives up electrons (becoming
a positive ion) to another different atom (which, gaining an electron,
becomes a negative ion)
Example: sodium chloride NaCl (salt)…these bonds are very tight,
strong, very stable.
• Covalent: In diatomic gases, like oxygen (O2), nitrogen (N2),
hydrogen (H2) where two atoms share electrons to complete each
other’s outer shells…these bonds are very strong. All organic
compounds are also covalently bonded.
• Metallic: localized exchange of electrons between small number of
atoms via an “electron cloud”
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• Physical state (solid, liquid, gas) depends on type and strength
of bonding:
• Liquids & gases: loosely bound atoms and molecules, free to
move independently of each other
• Solids: atoms are tightly bound together
…rigidly held in place by other atoms
-Turning into a solid: As bonds become
stronger, atoms begin to form ordered
patterns called lattices, which form
larger patterns called crystals, which
become solids
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• Molecular Structure
• Solid materials are usually Amorphous or Crystalline in
structure.
• Amorphous materials (like glass): No patterns, lattices, or
crystals…random order and do not exhibit a regular patter or
order.
• Crystalline Structures
Lattice structures: Imaginary lines connecting the centers of
atoms in a pattern. Form true repeatable boundaries or
patterns.
- Metals crystallize into one of seven types of lattice structures
(see Fig. 1-5, pg.13).
- Material properties (primary physical and mechanical) depend
on the crystal structure.
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Basic Metal Crystal Formations
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• Material Specifications
• A Specification is basically a statement of the minimum quality
of a desired product.
**Items typically included in a specification:
Method of manufacture or processing Forms, dimensions,
and finishes desired properties (See Table 1-1, pg. 21):
-General
-Chemical
-Physiochemical
-Thermal
-Electrical/Magnetic
-Optical
-Mechanical
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• Mechanical (focus of this course):
Tensile Strength
Compressive Strength
Shear Strength
Flexural Strength
Stiffness
Toughness
Hardness
Elasticity
Plasticity
Ductility
**See pg. 281 of Text
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• Standards
- Standards are the culmination of the efforts of experts in
particular materials, manufacturing and construction methods,
testing procedures, etc., to define commonly accepted
minimum requirements for those materials, methods, and
procedures.
- Organizations involved in developing standards are listed on
pg. 20. Those which are especially pertinent to building
construction include:
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• For structural and architectural materials, components, and
systems:
ACI
American Concrete Institute
AISC
American Institute of Steel
Construction
AISI
American Iron and Steel
Institute
ASCE American Society of Civil
Engineers
ANSI
American National
Standards Institute
ASTM American Society for Testing and Materials
www.astm.org.
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• For electrical materials, components, and
systems:
NEMA National Electrical
Manufacturers Association
IEEE
Institute of Electrical and
Electronic Engineers
ASTM
American Society for Testing
and Materials
For mechanical equipment:
ASME American Society of
Mechanical Engineers
ASTM
American Society for Testing
and Materials
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• We will focus in this course on general testing concepts, and
will look at ASTM tests for such items as structural steel,
concrete and rebar, glass, masonry, etc. In the lab, we will use
selected typical test procedures from those presented in
Appendix C of the text, which are simplified versions of actual
ASTM tests.
• The entire current set of ASTM standards constitutes a multivolume compendium which is kept in the Reference Dept. on
the main floor of the library. The volumes are arranged in
groups according to general categories (called “Sections”) of
materials or procedures. Each volume contains standards
which pertain to particular materials or procedures within a
subgroup within the general category.
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Professional Organizations
• All of the previously listed professional
organizations and others, work collectively
to establish test standards in conjunction
with the American Society of Testing
Materials (ASTM). Individual organizations
may have additional testing procedures or
protocols that may differ from ASTM
standard test.
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• The general categories (“Sections”) include (we will focus on
the first four sections):
Section 1:
Iron and Steel Products
Section 2:
Nonferrous Metal Products
Section 3:
Metals Test Methods and
Analytical Procedures
Section 4:
Construction
Section 5:
Petroleum Products, Lubricants,
and Fossil Fuels
Section 6:
Paints, Related Coatings, and
Aromatics
Section 7:
Textiles
Section 8:
Plastics
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Section
9: Rubber
Section 10: Electrical Insulation and
Electronics
Section 11: Water and Environmental
Technology
Section 12: Nuclear, Solar, and Geothermal
Energy
Section 13: Medical Devices and Services
Section 14: General Methods and
Instrumentation
Section 15: General Products, Chemical
Specialties, End Use Products
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• Each individual ASTM standard has a combination
letter/number designation. The letter designates the general
group under which the standard is contained; the number
indicates the order in which the was adopted into the group.
The letter groupings are:
A.
Ferrous metals
B.
Nonferrous metals
C.
Cement, concrete, ceramic, and masonry
materials
D.
Miscellaneous materials
E.
Miscellaneous subjects
F.
Specific applications of materials
C.
Corrosion, deterioration, and
degradation of materials
ES. Emergency Standards
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• Example:
If we were looking for criteria regarding bolts for fastening
structural steel, representative standards would be found in
Volume 01.08 (Fasteners) of Section 1 (Iron and Steel
Products), and would include standards A307, A325, and A490
for steel bolts.
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• Section 1: Iron and Steel Products
Volume 01.01
Volume 01.02
Volume 01.03
Volume 01.04
Volume 01.05
Volume 01.06
Volume 01.07
Volume 01.08
Steel-Piping, Tubing, Fittings
Ferrous Castings, Ferroalloys
Steel-Plate, Sheet, Strip, Wire
Steel-Structural, Reinforcing,
Pressure Vessel, Railway
Steel- Bars, Forgings, Bearing,
Chain, Springs
Coated Steel Products
Ships and Marine Technology
Fasteners
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• In Volume 01.08 (Fasteners), we would find:
Standard A307:
Standard Specification for Carbon Steel Bolts and
Studs, 60,000 PSI Tensile Strength
Standard A325:
Standard Specification for Structural Bolts, Steel,
Heat Treated, 120/105 ksi Minimum Tensile
Strength
Standard A490: Standard Specification for HeatTreated Steel Structural Bolts, 150 ksi Minimum
Tensile Strength
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American Society of Testing
Materials.
http://www.astm.org/
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