1. Discovery is dangerous…. but so is life
Discovery is dangerous….but so is life. A man unwilling to take risks is doomed never to learn, never to grow, never to live
- Pardot Kynes

2. Is this your design?

3. Looks like a materials problem
What is the material?
Some kind of steel?
Steel = iron + carbon
Steel?
What kind of steel?
Does it matter?

4. Types of steels .

5. AISI-SAE numbering system for steels XX XX
Types of steels
AISI-SAE numbering system for steels
XX XX
alloy element contents
wt % carbon x 100

6. AISI-SAE numbering system for steels XX XX
Types of steels
AISI-SAE numbering system for steels
XX XX
alloy element contents
wt % carbon x 100

7. So, does it matter?
Consider the properties of some steels
- all hot-rolled & normalized
Type Tensile strength
ksi
ksi
ksi
ksi
ksi
ksi

8. So, does it matter?
Consider the properties of some steels
- all hot-rolled & normalized
Type Tensile strength
ksi
ksi
ksi
ksi
ksi
ksi

9. (8640: Fe - 0.5%Cr - 0.5%Ni - 0.2%Mo - 0.4%C)
Apparently, changing carbon content changes
mech props significantly
Is changing carbon content only way
to change mech props?
Steel Tensile strength
1040 hot rolled and normalized ksi
1040 quenched and tempered at 400 F 130 ksi
8640 quenched and tempered at 400 F 270 ksi
(8640: Fe - 0.5%Cr - 0.5%Ni - 0.2%Mo - 0.4%C)

10. (8640: Fe - 0.5%Cr - 0.5%Ni - 0.2%Mo - 0.4%C)
Apparently, changing carbon content changes
mech props significantly
heat treatment
mechanical work
Steel Tensile strength
1040 hot rolled and normalized ksi
1040 quenched and tempered at 400 F 130 ksi
8640 quenched and tempered at 400 F 270 ksi
(8640: Fe - 0.5%Cr - 0.5%Ni - 0.2%Mo - 0.4%C)
add alloying elements

11. What do these things do in steels?
change C content
mechanical work
heat treat
alloying elements
change “structure”
Changing structure changes properties

12. What about Al alloys? Lotus Elise 190 hp 1984 lbs 0-60 mph - 4.9 sec
top speed mph mpg hiway $46K

13. Al??? Lotus versatile vehicle architecture system (VVA)
Almost completely "aluminum" - high pressure die-castings, stampings, and extrusions
Advanced Materials & Processes, July 2005, p 29
Al???

14. . OK…..which "aluminum" is it? 1050 1145 2014 2024 2219 2618 .

15. OK…..which "aluminum" is it?
Does NOT contain 0.61% carbon
Alloy designation NOT same as steels
In fact, no carbon at all in ordinary Al alloys

17. Here’s the scoop -
Number Major alloy addition
1xxx
2xxx Cu
3xxx Mn
4xxx Si
5xxx Mg
6xxx Mg & Si
7xxx Zn
8xxx other

18. So, does alloying affect the properties?
Al alloy containing 4.4% Cu (say 2024) can be heat treated to strength level much higher than that of pure Al
Yield strength Tensile strength
Low-strength ksi ksi
steel
Pure aluminum ksi ksi
Al alloy 2024-T ksi ksi

19. So, does alloying affect the properties?
Al alloy containing 4.4% Cu (say 2024) can be heat treated to strength level much higher than that of pure Al
Yield strength Tensile strength
Low-strength ksi ksi
steel
Pure aluminum ksi ksi
Al alloy 2024-T ksi ksi
What’s this??

20. T4 designates a heat treatment (Al alloys only)
"solution heat-treated, quenched, and naturally aged to a substantially stable condition"