Polymer Lecture 1 Structure property correlation-compressed
Page 1
Introduction to Engineering Materials and their properties
Presented by: Dr. Nimu Chand Reger (Assistant Professor)
Institution: National Institute of Technology Tiruchirappalli, Tamilnadu
Contact: nimu@nitt.edu
Date: 22-07-2024
Page 2
What is Material Science?
Correlation between microstructure and properties in Material Science and Engineering.
Microstructure depends on the processing route; performance is dictated by properties.
Figure 1: Materials Science Tetrahedron.
Date: 22-07-2024
Page 3
Materials Science and Engineering (MSE)
Interdisciplinary area combining various science and engineering fields.
Figure 1: Various areas merging with Materials Science & Engineering.
Date: 22-07-2024
Page 4
Broad applications of Engineering Materials
Metal Composites in F-35 aircraft models.
F-35A, F-358, F-35C specifications listed (Length, Wingspan, Weight).
Types of materials used in aircraft applications highlighted.
Date: 22-07-2024
Page 5
Engineering Materials Classification
Metals & Alloys: Steels, Al, Cu, Ag, Au, Pt
Polymers: Plastics (PVC, PTFE, PE), Fibers (Terylene, Nylon, Cotton).
Ceramics and Glasses: Oxides (MgO, Al2O3), Silica, Soda lime glass.
Composite Materials: General overview of engineering materials classification.
Date: 22-07-2024
Page 6
METAL
Definition: A solid material which is typically hard, shiny, malleable, fusible, and ductile.
Examples: Iron, Gold, Silver, Aluminum, Alloys like Steel.
Page 7
ALLOY
Definition: A material composed of two or more metals or a metal and a nonmetal.
Page 8
POLYMER
Definition: "Poly" (many) + "mer" (units) refers to materials made up of repeating units.
Page 9
COMPOSITE
Composite materials consist of two or more constituent materials with differing properties.
Combinations produce a material with characteristics different from individual components.
Page 10
Additional Examples of Composites
Boeing 787 applications and composition distribution highlighted.
Page 11
Types of Composites
Classifications: Laminar, Particle, Fiber Reinforced, Reinforced composites.
Page 12
CERAMICS
Defined as any inorganic, non-metallic material.
Page 13
CERAMICS Classification
Includes Metal Oxides, Carbides, Glass, Zirconia, Nitrides.
Page 14
(No content)
Page 15
AMORPHOUS MATERIAL
Characteristics: No regular arrangement of molecules.
Examples: Glass, Paraffin.
Properties include definite volume and shape; diffuse slowly.
Page 16
Crystalline Structure Classifications
Crystalline, Polycrystalline, Amorphous.
Page 17
Crystalline Material
Atoms arranged in regular lattice structure.
Page 18
POLYMORPHISM
Definition: Ability of solid material to exist in more than one form or crystal structure.
Page 19
(No content)
Page 20
(No content)
Page 21
Physical Properties
Important physical property: Density
Mathematical representation: Density (ρ) = mass (m) / volume (V).
Page 22
(No content)
Page 23
Melting Point
Definition: Temperature at which solid turns to liquid at atmospheric pressure.
Example: Melting point of ice is 0 °C.
Page 24
(No content)
Page 25
THERMAL PROPERTIES TO ADDRESS
Responses of materials to heat.
Key properties include:
Heat Capacity
Thermal Expansion
Thermal Conductivity
Thermal Shock Resistance
Page 26
HEAT CAPACITY
Defined: Energy required to raise temperature for a mole of material.
Units: J/mol-K.
Types: Cp (Constant Pressure), Cv (Constant Volume).
Page 27
Dependence of Heat Capacity on Temperature
Heat capacity increases with temperature.
Average energy of atomic vibrations increases with temperature rise.
Page 28
Atomic Vibrations
Described as lattice waves or phonons.
Page 29
Comparative Specific Heat
Extremely large Cp for polymers compared to metals and ceramics detailed.
Page 30
THERMAL EXPANSION
Phenomenon of materials changing size with temperature variations.
Page 31
ATOMIC PERSPECTIVE OF THERMAL EXPANSION
Analyze the interatomic separation with temperature changes.
Page 32
Comparison of Thermal Expansion Coefficients
Notable differences between materials and their expansion properties.
Page 33
Thermal Expansion Example
Example problem showing change in length of copper wire when cooled.
Page 34
THERMAL CONDUCTIVITY
Defined: Ability of a material to conduct heat.
Governed by the temperature gradient.
Page 35
Thermal Conductivity Values Comparative
Comparison of different materials (polymers, ceramics, metals) and their conductivity.
Page 36
Thermal Stresses
Result from thermal expansion/contraction and temperature gradients.
Page 37
Example Problem of Thermal Stress
Calculation to determine the temperature for which stress reaches -172 MPa.
Page 38
Continuing Example of Thermal Stress
Detailed calculation of thermal stress using formula.
Page 39
Causes of Thermal Stress
Describes the dynamics of non-uniform heating/cooling leading to thermal stress.
Page 40
APPLICATION OF POLYMERS
Example: Silica tiles used in Space Shuttle Orbiter.
Page 41
THERMAL DIFFUSIVITY
Measures ability to conduct thermal energy relative to storage capacity.
Page 42
Summary of Thermal Properties
Heat capacity, Coefficient of thermal expansion, Thermal conductivity, Thermal shock resistance defined.
Page 43
(No content)
Page 44
MECHANICAL PROPERTIES
Definitions of strain and stress.
Page 45
Key Mechanical Properties
Strength, Stiffness, Elasticity, Plasticity, etc.
Page 46
Continuation of Mechanical Properties
Ductility, Brittleness, Malleability, Toughness described.
Page 47
Continuation
Machinability, Resilience, Creep, Fatigue, Hardness.
Page 48
Wear
Definition and description of wear and degradation of materials.
Page 49
MAGNETIC PROPERTIES
Overview of magnetic behavior in metals and ceramics.
Page 50
APPLIED MAGNETIC FIELD
Effect of current through coils and field relationships.
Page 51
RESPONSE TO MAGNETIC FIELDS
Understanding magnetic induction and material interactions.
Page 52
MAGNETIC SUSCEPTIBILITY
Measures the response of materials to magnetic fields detailed.
Page 53
MAGNETISM
Overview of magnetic forces and atomic structure relationships.
Page 54
BOHR MAGNETON
Magnetic moments discussed in terms of the electronic structure.
Page 55
MAGNETIC MOMENTS FOR TYPES
Diamagnetic, paramagnetic, ferromagnetic materials compared.
Page 56
FERRO AND FERRI-MAGNETIC MATERIALS
Behavior under applied magnetic fields explained.
Page 57
PERMANENT MAGNETS
Processes for aligning magnetic moments in materials.
Page 58
MAGNETIC STORAGE
Mechanism of information storage via magnetizing materials.
Page 59
ELECTRICAL PROPERTIES OF MATERIALS
Basic laws of electricity and concepts of current flow in materials.
Page 60
BASIC LAWS AND ELECTRICAL PROPERTIES
Definitions of electric potential, current, and resistance.
Page 61
CONDUCTIVITY
Definitions and inverses of resistivity given.
Page 62
CONDUCTION IN POLYMERS AND IONIC MATERIALS
Conductivity mechanisms in different materials compared.
Page 63
CONTINUATION ON ELECTRICAL PROPERTIES
Detailed concepts on ionic conduction in polymeric and ionic materials.
Page 64
**FOR LISTENING
Questions session.
Page 65
Lecture 1 on Introduction to Polymers: Overview of polymer science and engineering.