Mechanical Properties of Metals
Learn about mechanical properties of metals from this book: Strain, Conventional & True Stresses. Elastic Stress–Strain Relations, Yield Strength, Ductility & Fracture Strength and much more.
Mechanical Properties and Working of Metals and Alloys
By Amit Bhaduri (2018)
SELECTED CONTENTS
Part I – Mechanical Properties of Metals and Alloys
1 Tension
- Introduction
- Strain
- Conventional and True Stresses
- Elastic Stress–Strain Relations
- Elements of Plastic Deformation
- Types of Tensile Stress–Strain Curve
- Linear Elastic Properties
- Nonlinear Elastic Properties
- Inelastic Properties
- Yield Strength
- Ultimate and True Tensile Strength
- Ductility
- Fracture Strength and True Fracture Strength
- Toughness
- Influence of Temperature on Tensile Properties
- Strain Rate
- Testing Machine
- Notch Tensile Test
- Tensile Fracture
- Solved Problems
2 Compression
- Introduction
- Standard Specimen
- Elastic Range
- Plastic Range
- Stress and Strain
- Strain Rate
- Brittle Materials
- Ductile Materials
- Bauschinger Effect
- Advantages of Compression Over Tension Test
- Problems in Compression Test
- Compressive Failure of Materials
- Solved Problems
3 Hardness
- Introduction
- Classification of Hardness
- Precautions to Avoid Erratic Hardness Measurement
- Mohs’ Scale of Hardness
- File Hardness Test
- Brinell Hardness
- Principle of Testing
- Derivation for BHN
- Indenters, Loads and Loading Periods
- Method of Testing
- Anomalous Behaviour
- Advantages and Disadvantages
- Meyer Hardness
- Rockwell Hardness
- Principle of Testing
- Loads
- Indenters
- Direct-Reading Hardness Dial
- Hardness Scale
- Method of Testing
- Advantages
- Rockwell Superficial Hardness
- Principle of Operation
- Superficial Hardness Scale
- Merits and Demerits
- Vickers Hardness
- Indenters and Loads.
- Principle of Operation
- VHN Versus BHN
- Operational Method
- Minimum Thickness of Test Section
- Anomalous Behaviour
- Advantages and Disadvantages
- Microhardness (Knoop Hardness)
- Monotron Hardness
- Shore Scleroscope Hardness
- Poldi Impact Hardness
- The Herbert Pendulum Hardness
- Nanohardness
- Relationship to Flow Curve and Prediction of Tensile Properties
- Solved Problems
4 Bending
- Introduction
- Pure Bending
- Beam Design in Pure Bending
- Linear Elastic Behaviour
- Yielding
- Nonlinear Stress–Strain Relations
- Shear Stresses in Elastically Bent Beam
- Solved Problems
5 Torsion—Pure Shear
- Introduction
- State of Stress and Strain
- Relation Between Shear Strain and Angle of Twist
- Torsional Stresses in Elastic Range
- Torsional Stresses for Plastic Strains
- Behaviour of Material in Torsion
- Elastic Properties
- Inelastic Properties
- Torsion Test Versus Tension Test
- Failure Under Torsion
- Solved Problem
6 Impact Loading
- Dynamic Loading and Brittle Fracture
- Notched-Bar Impact Tests
- Calculation of Energy Relations
- Impact Properties
- Metallurgical Factors Affecting Impact Properties
- Instrumented Charpy Impact Test
- Additional Large-Scale Fracture Test Methods
- Fracture Analysis Diagram (FAD)
- Solved Problems
7 Creep and Stress Rupture
- Long-Time Loading at High Temperature
- The Creep Curve
- Strain–Time Relations
- Creep Rate–Stress–Temperature Relations
- Steady-State Creep
- Creep Deformation Mechanisms
- Deformation Mechanism Map
- The Stress-Rupture Test
- Concept of ECT and Elevated-Temperature Fracture
- Presentation of Engineering Creep Data
- Parameter Methods to Predict Long-Time Properties
- Stress Relaxation
- Materials for High-Temperature Use
- Creep Under Multiaxial Stresses
- Indentation Creep
- Solved Problems
8 Fatigue
- Fatigue Failure
- Stress Cycles
- Standard Fatigue Test
- The S–N Diagram and Fatigue Properties
- Reason for Existence of Fatigue Limit
- Statistical Nature of Fatigue
- Fatigue Crack Nucleation and Growth
- Fatigue Crack Growth Rate
- Effect of Mean Stress
- Stress Fluctuation and Cumulative Fatigue Damage
- Overstressing, Understressing and Coaxing
- Cumulative Fatigue Damage
- Stress Concentration Effect
- Size Effect
- Surface Effects and Surface Treatments
- Surface Roughness and Treatment
- Surface Properties and Treatment
- Surface Residual Stress and Treatment
- Metallurgical Processes Detrimental to Fatigue
- Effect of Metallurgical Variables
- Frequency of Stress Cycling
- Temperature Effect
- Low Temperature
- High Temperature
- Thermal Fatigue
- Chemical Effects
- Cyclic Strain-Controlled Fatigue
- Low-Cycle Fatigue
- Strain–Life Equation and Curve
- Creep–Fatigue Interaction
- Increasing Amplitude Tests
- Step Test
- Prot Test
- Solved Problems
9 Fracture
- Introduction
- Theoretical Cohesive Strength
- Inglis Analysis of Stress Concentration Factor
- Effects of Notch
- Characteristic Features of Fracture Process
- Energy to Fracture
- Macroscopic Mode of Fracture
- Microscopic Mode of Fracture or Fractography
- Griffith Theory of Brittle Fracture
- Applicability of Griffith Theory
- Modification of Griffith Theory
- Elastic Strain Energy Release Rate
- Stress Intensity Factor
- Different Crack Surface Displacements
- Relationship Between Energy Release Rate and Stress Intensity Factor
- Fracture Toughness
- Plastic Zone at Crack Tip
- Effective Stress Intensity Factor
- Fracture Toughness: Plane Stress Versus Plane Strain
- Plane-Strain Fracture Toughness (KIc) Testing
- Specimen Size, Configurations, and Preparation
- Test, Interpretation of Result and Calculation of (KIc)
- Kc from KIc
- Design Philosophy with Fracture Toughness
- Solved Problems
Part II – Mechanical Working of Metals and Alloys
10 Fundamentals of Mechanical Working
- Classification of Mechanical Forming Processes
- Aims of Mechanical Working
- Different Forming Processes
- Temperature and Strain Rate
- Cold-Work-Anneal Cycle
- Temperature Limits for Hot Working
- Hot Working Versus Cold Working
- Warm Working
- Temperature Change During Working
- Strain-Rate Effects
- Choice of Allowable Hot Working Temperature Range
- Friction
- Coulomb’s Law of Sliding Friction
- Shear Friction Factor
- Measurement of Friction
- Adverse Effects of Friction
- Beneficial Effects of Friction
- Lubrication
- Material Transfer
- Functions and Characteristics of a Lubricant
- Lubrication Mechanism
- Mechanics of Working Process
- Slab Method
- Uniform-Deformation Energy Method
- Slip-Line Field Theory
- Upper-Bound Technique
- Finite Element Method
- Deformation-Zone Geometry
- Anisotropy of Mechanical Properties
- Solved Problems
11 Forging
- Classification of Forging Processes
- Types of Forging Operations
- Forging Equipments
- Drop Forging Hammer
- Forging Press
- Open-Die Forging
- Closed-Die or Impression-Die Forging
- Material Loss During Forging
- Plane Strain Forging of Flat Rectangular Plate
- Plane Strain Forging of Strip with Inclined Dies
- Forging of Flat Circular Disk
- Forging of Circular Disk by Conical Pointed Dies
- Forging Defects
- Solved Problems
12 Rolling
- Fundamentals of Rolling
- Terminology of Rolled Product
- Different Methods of Rolling
- Quantities Characterizing Deformation
- Classification of Rolling Mills
- Cluster Mill
- Sendzimir Cold-Rolling Mill
- Sendzimir Planetary Hot-Rolling Mill
- Pendulum Mill
- Contact-Bend-Stretch Mill
- Universal Mill
- Rolling Practice
- Hot Rolling
- Cold Rolling
- Deformation Zone in Rolling
- Angle of Bite
- Neutral Point
- Ekelund Expression for No-Slip Angle
- Forward Slip
- Relation with No-Slip Angle
- Measurement of Forward Slip
- Importance of Forward Slip
- Elastic Deformation of Rolls
- Simplified Assessment of Rolling Load
- Theory of Rolling: Derivation of Differential Equation
of Friction Hill - Bland and Ford Theory of Cold Rolling
- Sims’ Theory of Hot Rolling
- Lever Arm Ratio, Roll Torque and Mill Power
- Minimum Thickness in Rolling
- Factors Controlling Rolling
- Gauge Control
- Defects in Rolled Products
- Roll Pass Design Fundamentals
- Types and Shapes of Passes
- Gap and Taper of Sides in Pass
- Pass Arrangement
- Pass Sequences Used in Rolling of Billets to Rods
- Pass Sequences Used in Rolling of Billets to Square Bars
- Manufacture of Tubes and Pipes
- Production of Seamless Tube and Pipe by Hot Rolling
- Solved Problems
13 Extrusion
- Introduction
- Comparison with Rolling
- Two Basic Methods of Extrusion
- Direct Versus Indirect Extrusion
- Extrusion Equipments
- Extrusion Dies
- Metal Flow During Extrusion
- Factors Influencing Extrusion
- Estimation of Extrusion Load
- Open-Die, Indirect and Hydrostatic Extrusions
- Direct Extrusion Through Conical Converging Die
- Direct Extrusion Through Square Die
- Selection of Proper Equation for Ram Load and Stress
- Strain Rate in Extrusion
- Extrusion Defects
- Impact Extrusion
- Hydrostatic Extrusion
- Basic Difference Between Hydrostatic and Conventional Extrusion
- Conventional Hydrostatic Extrusion
- Differential Pressure Hydrostatic Extrusion
- Advantages of Hydrostatic Extrusion
- Disadvantages of Hydrostatic Extrusion
- Seamless Tube Production by Extrusion
- Extrusion of Cable Sheathing
- Application of Slip-Line Field to Steady-State Motion
- 50% Plane-Strain Frictionless Extrusion
- 2/3 Plane-Strain Frictionless Extrusion
- Upper-Bound Solution for Plane-Strain Frictionless Extrusion
- Solved Problems
14 Drawing: Flat Strip, Round Bar and Tube
- Introduction
- Strip Drawing Through Wedge-Shaped Dies
- Drawing Stress with Friction
- Frictionless Ideal Drawing Stress
- Maximum Reduction of Area in a Single Pass With and Without Friction
- Drawing Stress for Work-Hardening Strip
- Drawing Stress of Strip Through Cylindrical Dies
- Treatments of Work Metal Prior to Drawing
- Drawing Equipments
- Conical Converging Die
- Drawing of Rod and Wire
- Drawing Load and Power with Friction and Back Tension
- Frictionless Ideal Drawing Stress
- Maximum Reduction of Area in a Single Pass
- Redundant Deformation
- Drawing Stress Versus Die-cone Angle: Optimum Cone Angle, Dead Zone and Shaving
- Tube Drawing
- Close-Pass Plug Drawing Stress and Load
- Close-Pass Mandrel Drawing Stress
- Maximum Reduction of Area in a Single Pass
- Tube Sinking
- Equilibrium Condition of Forces Acting on a Floating Plug
- Application of Slip-Line Field to Strip Drawing
- Upper-Bound Solution for Strip Drawing
- Solved Problems
15 Deep Drawing
- Fundamentals of Deep Drawing
- Stresses and Deformation in a Deep-Drawn Cup
- Deep-Drawing Load
- Derivation of Mathematical Expression
- Formability
- Strain Distribution
- Maximum Strain Levels: The Forming Limit Diagram
- Deep Drawability
- Plastic Strain Ratio
- Drawing Ratio
- Effects of Process and Material Variables
- Effect of Drawing Ratio
- Radii of Die and Punch
- Punch-to-Die Clearance
- Drawing Speed
- Friction and Lubrication
- Restraint of Metal Flow
- Material Parameters
- Evaluation of Formability
- Marciniak Biaxial Stretching Test
- Swift Cup Test
- Ericksen and Olsen Cup Tests
- Fukui Conical Cup Test
- Hole Expansion Test
- Forming Limit Diagram
- Deep Drawing Defects
- Solved Problems
16 High-Energy Rate Forming
- Introduction
- Fundamentals of HERF Process
- Explosive Forming
- Electromagnetic Forming
- Electrohydraulic Forming
- High-Energy Rate Forging
- Other HERF Methods
- Solved Problems
The figures from this book that are useful for understanding aluminum:
Fig. 10.11 – Schematic representation of the cold-work-anneal cycle illustrating the effects on mechanical properties and microstructure (Smith 1969)
Fig. 13.1 – Extrusion of solid by (a) direct extrusion and (b) indirect extrusion
Fig. 13.2 – Schematic view of various extrusion process tooling
(a) Typical curves of extrusion pressure versus ram displacement
for direct and indirect extrusion
at a relatively constant billet temperature and
a constant ram speed after initial acceleration;
(b) Division of deformation work for direct extrusion into four zones – I, II, III and IV
Fig. 13.7
Fig. 13.8 – Metal flow during extrusion:
(a) Flow along a diagonal path during early stage of extrusion;
(b) Flow normal to force direction at later or final stage of extrusion