AAB2092
Phase Transformations in
Metallic Materials
Ts Dr Norlin Nosbi
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COURSE OUTCOMES (CO):
At the end of this course, students should be able to:
CO1
CO2
CO3
Analyze the classes of material, distinguishing and phases in metal alloys, stable and metal stable phases
Explain thermodynamic and Kinetic of transformation, transformation type and mechanism (e.g., diffusional
and solid state transformation) and their influence on mechanical properties
Design a heat treatment for various metal alloys for transformation new microstructure and their influence
of mechanical properties.
PROGRAMME OUTCOMES (PO):
At the end of this course, students should be able to:
PLO1
Acquire and apply engineering fundamentals to complex Materials Engineering problems.
PLO2
Identify, formulate and solve complex Materials Engineering problems using creativity and innovativeness.
PLO3
Design and develop solutions for complex Materials Engineering problems.
Aluminium alloy
TODAY’S OUTCOME
THE STUDENT SHOULD BE
ABLE TO UNDERSTAND:
-INTRODUCTION ON ALUMINIUM ALLOY,
CHEMISTRY, FABRICATION, HEAT-TREATMENT
AND APPLICATIONS
Aluminium Alloy
ISSUE TO ADDRESS...
What types of aluminium alloy?
What is the applications for this aluminium?
Advantages using Aluminium alloy?
Active Learning: Think pair share (15 minutes)
Show all the issue that need to be address above.
Contents
Introduction
Chemistry
Course outline
Classification
Applications
Manufacturing
Heat treatment
Common Defects
Conclusions
7
Introduction Abundance
All Others
Iron
Oxygen
Silicon
Aluminum Oxide / Bauxite
8
Advantages
Introduction
High strength
to weight ratio
High electrical
and thermal
conductivity
High reflectivity
and resistance to
corrosion
Non-toxic (ideal
for packaging
and cooking
material)
Ductility-easy to
cold work and
fabricate
9
History
• Aluminum Production
• The first commercial batch of Aluminum
was produced in 1888
• Production Capabilities Lower the Price
– Between 1888 and 1893 Aluminum dropped
from $4.86/lb to $.78/lb
10
Application
• Early uses for Aluminum
• Cooking utensils
• Electrical wire and cable
• Foil
• Auto bodies
• Engine parts used by the
Wright Brothers’
11
Chemistry Alloying Elements
Principal
Alloying
Elements
Cu, Mn, Mg, Si,
Zn, Fe
Additional
Alloying
Elements
Ti, B, Zr, Cr, Ni, Bi,
Pb
12
Role of Alloying Elements
Al
1. Increases strength
and hardness
2.If >12% makes the
alloy brittle
3. Hot cracking tendency
4. Decreases corrosion
Cu
resistance
13
Role of Alloying Elements
Al
1.Increases yield and
tensile strength
2. Improves ductility
3.Good resistance to
corrosion
Mn
4. Decrease resistivity
Manganese
14
Role of Alloying Elements
Al
1.Increases tensile
strength and hardness
uptil 13% wt.
2.Decrease the hot
cracking
3. Good resistance to
corrosion
Si
Silicon
15
Role of Alloying Elements
Al
1.Increases strength
and hardness
2.Good resistance to
corrosion
Mg
3.Increase weldability
and machinability
Magnesium
16
Role of Alloying Elements
Al
Zn
1.Gives heat treatable
alloys when combined
with Mg
2. Increase strength
and
hardness
3.Increased toughness
but susceptible to stress
corrosion cracking
17
Classification Alloy Designation System
typically contain low
percentages of alloying
elements, specifically
silicon, which is usually
less than 1%
Al
same elements as wrought,
but in greater amounts; and
silicon content, generally in
the range 1-12%, may
exceed in some alloys.
18
Classification Alloy Designation System
Standardize by
Applications 1XXX
20
Applications 2XXX
21
Applications 3XXX
22
Applications 4XXX
23
Applications 5XXX
24
Applications 6XXX
25
Applications 7XXX
26
Production Wrought Al Alloys
27
Extrusion
Process
Video:
https://www.youtube.com/watch?v=
baM5hNnBcT8
28
Heat
Treatment
Al Alloys
• Annealing Treatment
• Solution heat treatment
• Precipitation (Hardening)
treatment
29
Aluminium alloy Forming
Processes
(Microstructure effects)
Heat Treatment
Before Solution Heat Treatment
After Solution Heat Treatment
31
Heat Treatment
25
Al-Cu phase diagram showing three steps in precipitation hardening
Aluminium alloy Forming
Processes
(Defects)
Common Defects
Casting
Defects
Heat
Treatment
Defects
Defect
Extrusion
Defects
Forging
Defects
34
Casting Defects
Cracks
Porosity
Inclusions
Segregation
35
Cracks Types
Centric
Radial
Loop
Transverse
36
Cracks 7075
37
Cracks 2024
38
Inclusions Optical Images
39
Inclusions SEM Images
40
Inclusions SEM Analysis
41
Inclusions Fracture surface
42
Inclusions Fracture surface
43
Extrusion Defects
Extrusion
tears/ cracks
Scratches
Fish scaling
Un-even wall
thickness
Layer
Formation
Coarse grain
ring
44
Drawing Defects
Scratch
Bumped ring
Un-uniformity of
wall thickness
Crack
Wrinkle
End break
45
Cracks in Extrusion Unetched form
46
Cracks in Extrusion T6 etched form
47
Heat treatment Defects
Unqualified
mechanical
properties
Over firing
Coarse grain
Quenching cracks
48
Grain Coarsening
49
Control of Grain Coarsening
50
The student should be able
to understand:
Today’s outcome
COMPLETED
Introduction on Aluminium
alloy, chemistry,
fabrication, heat-treatment
and applications