Materials Science: Cast Iron and Ferrous Metals

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Questions and Answers

What is a characteristic of cast iron?

It is highly flexible.

It is fusible. (correct)

It cannot be hardened.

It rusts easily.

Which type of cast iron is characterized by a silver white luster upon fracturing?

Grey Cast Iron

White Cast Iron (correct)

Malleable Cast Iron

Chilled Cast Iron

What is the primary constituent of ferrous metals?

Lead

Iron (correct)

Copper

Aluminum

Which metal classification can be worked after casting?

Wrought Metal Signup and view all the answers

Chilled cast iron is produced by casting molten metal against what?

A metal chiller Signup and view all the answers

Which of the following properties distinguishes metals from other materials?

High thermal conductivity Signup and view all the answers

What is the carbon content range for grey cast iron?

3% to 4% Signup and view all the answers

Which of the following properties is NOT associated with ferrous metals?

Conducts electricity poorly Signup and view all the answers

Which process is characterized by large deformations and a relatively small surface area to volume ratio?

Bulk Processes Signup and view all the answers

What is a characteristic of sheet metalworking compared to bulk processes?

Larger surface area to volume ratio Signup and view all the answers

In machining operations, which of the following methods is specifically used for material removal?

Turning Signup and view all the answers

What is the purpose of hardening processes in relation to machining?

To improve shear strength Signup and view all the answers

Which of the following processes is NOT considered a machining process?

Welding Signup and view all the answers

Which mechanical property describes a material's ability to return to its original shape after the load is removed?

Elasticity Signup and view all the answers

Which of the following joining methods creates a permanent connection between parts?

Welding Signup and view all the answers

The property of a material that allows it to be drawn into thin wires is known as:

Ductility Signup and view all the answers

Which type of polymer is formed when only one type of monomer is used?

Homopolymers Signup and view all the answers

What is the primary purpose of copolymerization in polymers?

To enhance and improve the property of the final product Signup and view all the answers

Which of the following is an example of step-reaction polymerization?

PET Signup and view all the answers

What characteristic distinguishes high-density polyethylene (HDPE) from low-density polyethylene (LDPE)?

HDPE molecules can be packed closely together. Signup and view all the answers

What does polymer branching primarily affect in a polymer material?

The density and properties of the polymer Signup and view all the answers

Which factor does NOT affect the properties of polymers?

Color Signup and view all the answers

What type of sequence results from linking three different types of monomers together?

Terpolymers Signup and view all the answers

A polymer is considered polar if it has which of the following characteristics?

Positive and negative poles due to unequal sharing of electrons Signup and view all the answers

What is the main purpose of chemical vapor deposition?

To produce very pure, high-performance films Signup and view all the answers

Which process involves depositing one-atom-thick layers on a surface?

Atomic layer epitaxy Signup and view all the answers

What is the primary function of dip pen lithography?

To write on a surface using a chemically dipped tip Signup and view all the answers

What potential health effect do nanoparticles have according to experimental evidence?

They may cause genetic damage Signup and view all the answers

Which of the following is a high-volume process to produce nanoscale devices?

Roll-to-roll processing Signup and view all the answers

What is a significant concern regarding the environmental impact of nanomaterials?

They can behave unpredictably due to their minute size Signup and view all the answers

Which process is used to create nanoscale features by stamping them onto a surface?

Nanoimprint lithography Signup and view all the answers

What are some observed effects of nanoparticles on invertebrates and fish?

Negative effects on behavior, reproduction and development Signup and view all the answers

Which of the following is not a field of science that focuses on the study of materials?

Chemical Biology Signup and view all the answers

What do the lattice points in a crystal structure represent?

Atoms, ions, or molecules Signup and view all the answers

Which of the following best defines a unit cell in crystallography?

A tiny block forming the basic structural unit Signup and view all the answers

Which of the following terms refers to the periodic arrangement of points in three-dimensional space?

Space Lattice Signup and view all the answers

How many lattice parameters are there in defining the lattice structure?

6 Signup and view all the answers

What aspect of crystalline solids does the arrangement of atoms, ions, or molecules affect?

The mechanical properties of the material Signup and view all the answers

Which of the following is a correct characterization of a lattice space?

The space covered by the lattice points Signup and view all the answers

What is true about the unit cell in a crystal structure?

It can represent infinite arrangements Signup and view all the answers

What is the approximate composition of cobalt-based alloys?

~ 40% Co and ~ 20% chromium Signup and view all the answers

Which property of super alloys is NOT emphasized as being excellent?

Room temperature strength Signup and view all the answers

What is the typical operating temperature range for super alloys?

1100°C to 1200°C Signup and view all the answers

What is the main effect of grain size in metals when they are heated?

Grain size increases, reducing strength Signup and view all the answers

What is the purpose of the annealing process?

To add ductility to the metal Signup and view all the answers

Which process involves heating a hardened metal and allowing it to cool slowly?

Tempering Signup and view all the answers

What is the primary purpose of quenching in metal processing?

To produce a very hard but brittle metal Signup and view all the answers

What does cold working mainly refer to in metal processing?

Strengthening metals by changing shape without heat Signup and view all the answers

Study Notes

Introduction to Engineering Materials

Engineering materials are crucial for everyday life and survival.
Gold was the first metal used, followed by copper.
Areas of science studying materials include Engineering Materials, Material Science, and Materials Engineering.

Basic Concepts of Crystal Structure

Properties of crystalline solids are determined by their crystal structure.
Atoms, ions, or molecules are arranged in a periodic manner.
A space lattice or lattice is a 3D network of points in a material.
A lattice point represents an atom, located where the lines intersect.
A lattice array shows the arrangement of lattice points.
A lattice space shows the region covered by lattice points.
A unit cell is a small repeating block representing the symmetry of a crystal structure.
Unit cells can be defined as finite representations of an infinite lattice or as small repeating entities, and basic structural units and building blocks of crystal structure.

Lattice Parameters

Lattice parameters (a, b, c, α, β, γ) describe the dimensions and angles of a unit cell.
These parameters are typically in the range of a few ångströms (0.1 nanometers).
Seven crystal systems are defined based on the relationships between lengths and angles (a = b = c and α = β = γ = 90° for cubic).

Basic Types of Crystal Systems

Different crystal systems are defined by the relationships between the unit cell axes (a, b, c) and the angles between them (α, β, γ).
Cubic, Hexagonal, and Tetragonal systems are included.

Bravais Lattices

There are 14 types of Bravais lattices.
These are categorized based on the types of centering (Face-Centered, Body-Centered, and Base-Centered).

Metallic Crystal Structures

Simple Cubic (SC)
Atoms are located at the corners of a cube.
Low packing density.
Body-Centered Cubic (BCC)
Atoms are at the corners and center of the cube.
Coordination number is 8.
Face-Centered Cubic (FCC)
Atoms are at the corners and face centers of the cube.
Higher packing efficiency.
Hexagonal Close-Packed (HCP)
Layers of atoms arranged in hexagonal patterns.
High packing efficiency.

Crystallographic Directions

Crystallographic directions are lines or vectors in a crystal.
Directions are specified using coordinate notation [uvw].
Converting between four- and three-index notation is possible

Properties of Crystals

Atomic Packing Factor (APF) - the ratio of atomic volume to unit cell volume.
Planar Density - density of atoms on a given plane.
Linear Density - number of atoms per unit length along a given direction.

Metals

Metals are used in various engineering applications.
Iron is a popular engineering metal.
All metals have a crystalline structure.

Alloys

An alloy is a mixture or compound of two or more elements, at least one being metallic.
Alloying enhances properties like strength and hardness.
Alloys are classified into solid solutions and intermediate phases.

Solid Solutions

Solid solutions occur when one element dissolves into another to form a single-phase structure.
The solvent is typically metallic, while the dissolved element can be either metallic or non-metallic.
Solid solutions are classified as substitutional or interstitial.
Substitutional: atoms of the solute element replace atoms of the solvent element in the lattice.
Interstitial: atoms of the solute element fit into spaces between the solvent atoms.

Intermediate Phases

Intermediate phases form when the concentration of one element exceeds its solid solubility limit.
They have intermediate compositions and unique crystalline structures.

Importance of Metals

High stiffness and strength
Good electrical and thermal conductivity
Toughness
Cost effectiveness, especially for steel

Metals Used in Manufacturing Processes

Cast Metal - prepared by casting.
Wrought Metal - mechanically worked after casting.
Powdered Metal - treated using powders for shaping.

Classification of Metals: Ferrous and Non-ferrous

Ferrous metals: contain iron as the main constituent (e.g., cast iron, wrought iron, steel).
Non-ferrous metals: do not contain iron as the main constituent (e.g., aluminum, copper, tin, zinc, lead).

Ferrous Metals: Properties and Types

Cast iron (C.I.) - high carbon content (2-4.23%).
Properties: Hard, Brittle, Fusible, Non-Temperable, Resistant to Corrosion
Grey cast iron
White cast iron
Chilled cast iron
Malleable cast iron
Toughened cast iron
Wrought iron - almost pure iron (0.15% carbon).
Properties: Soft, Malleable, Ductile, Tough, High Melting Point, Corrosion-Resistant
Steel - iron alloy with a carbon content up to 2%.
Properties: Hardened and Tempered, Malleable, Ductile, Forgeable
Types: Low Carbon (Mild Steel), Medium Carbon, High Carbon; each with variables in properties and applications (springs, tools, structural components).
Alloy steels - steels with additional elements to obtain specific properties.
Alloy steels - Chromium, Cobalt, Manganese, Tungsten, Vanadium, Nickel. Each alloyed steel with different benefits

Non-ferrous Metals: Properties and Uses

Aluminum - a lightweight, corrosion-resistant metal, good conductor of heat and electricity
Copper - a reddish-brown metal, excellent conductor of electricity and heat
Tin - a silvery-white, soft metal resistant to corrosion
Zinc - a bluish white metal, used for galvanization of steel.
Lead - a soft, heavy metal, used in various applications.

Superalloys

Materials with superior high temperature strength, hardness, creep resistance, and corrosion resistance used in high-temperature applications (e.g., jet engine components). Superalloys are categorized as Iron-based, Nickel-based, or Cobalt-based.
Understanding how superalloys are used helps determine their importance in demanding high-temperature systems.

Metal Processing

Processing methods affect the mechanical properties of the material.
Grain size affects material strength and ductility.
Quenching - hardening by rapid cooling from a high temperature.
Annealing - softening by heating and slow cooling.
Tempering- a post-hardening heat treatment that enhances toughness and reduces brittleness.
Cold working - improving a material or component by changing its shape without altering its temperature.

Metal Manufacturing: Production

Casting - producing metal parts by pouring molten metal into molds.
Powder processing - forming parts by pressing and sintering powdered metal.
Metal forming - changing the shape of metal pieces by applying stress (e.g., rolling, forging).

Metal Manufacturing: Fabrication

Processes that alter the shape or dimension of metal components.
Deformation includes bending, rolling, forging, and drawing, used to change the shape and size.
Bulk, like Rolling or forging, or Sheet-based, like drawing or stamping
Machining - material removal methods to refine components. Includes grinding, drilling, milling, shaping etc
Joining - combining multiple components (e.g., welding, brazing).
Finishing - includes coating or plating, used to enhance desired properties.

Mechanical Properties of Materials

Strength, Elasticity, Plasticity, Ductility, Tensile Strength are significant measures of material behavior under load.
Stress is the ratio of force on an object to the area upon which it is applied when considering tensile, compressive, shearing, or bearing stress.
Strain is the change in length when forces are applied (unitless quantity).
Stress-Strain Diagram - a graphical representation of stress versus strain, that can indicate whether a material is ductile or brittle, or the threshold before yielding.

Polymers

Polymers are high molecular weight materials formed by linking monomers.
Extensive use in various applications.
Types of polymerization - Addition and Condensation. Branching affects the properties of the polymer, with linear polymers being more dense and strong.
Types of polymers include homopolymers and copolymers (which combine two or more different types of monomers).
Polarity influences various material properties.

Nanomaterials

Nanomaterials are materials with structures at the nanoscale (1-100nm).
Manufacturing (either "top-down"), or "bottom-up" from atomic level components").
Properties: influenced by their size, shape, surface area, ratio of width/height/length, and how effectively they stick together.
Potential real-world effects in health and the environment. Manufacturing methods, such as chemical vapor deposition, and atomic layer epitaxy are now used.

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Description

Test your knowledge on the characteristics and properties of cast iron and ferrous metals. This quiz covers topics such as carbon content, metal classifications, and machining processes. Perfect for students studying materials science or engineering.