1. The ability to learn is a gift The capacity to learn is a skill The willingness to learn is a choice - Rebec of Ginaz The ability to learn is a gift The capacity to learn is a skill The willingness to learn is a choice - Rebec of Ginaz

2. Re: question from last class - Mech prop data for annealed plain carbon steels Re: question from last class - Mech prop data for annealed plain carbon steels tensile yield tensile/yield

3. Also from last class: Densities of some materials: Al alloys2.63-2.82 gm/cm 3 steels6.92-9.13 Ti alloys4.43-4.70 Mg alloys1.77-1.78 Cu alloys7.47-8.94 glasses2.4-2.7 HDPE0.96 PMMA1.22 epoxies1.25 Also from last class: Densities of some materials: Al alloys2.63-2.82 gm/cm 3 steels6.92-9.13 Ti alloys4.43-4.70 Mg alloys1.77-1.78 Cu alloys7.47-8.94 glasses2.4-2.7 HDPE0.96 PMMA1.22 epoxies1.25

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

5. 105011452014202422192618 30033004310540324043 5005 505250835154518252625652 601060616262646370057050 707270757175717874757229. 105011452014202422192618 30033004310540324043 5005 505250835154518252625652 601060616262646370057050 707270757175717874757229. OK…..which "aluminum" is it?

6. 105011452014202422192618 30033004310540324043 5005 505250835154518252625652 601060616262646370057050 707270757175717874757229 105011452014202422192618 30033004310540324043 5005 505250835154518252625652 601060616262646370057050 707270757175717874757229 OK…..which "aluminum" is it? Alloy designation NOT same as steels In fact, no carbon at all in ordinary Al alloys Does NOT contain 0.61% carbon

7. 105011452014202422192618 30033004310540324043 5005 505250835154518252625652 601060616262646370057050 707270757175717874757229 105011452014202422192618 30033004310540324043 5005 505250835154518252625652 601060616262646370057050 707270757175717874757229

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

9. Al alloy containing 4.4% Cu (say 2024) can be heat treated to strength level much higher than that of pure Al So, does alloying affect the properties? Yield strength Tensile strength Low-strength 30 ksi 60 ksi steel Pure aluminum 5 ksi 13 ksi Al alloy 2024-T4 47 ksi 68 ksi Yield strength Tensile strength Low-strength 30 ksi 60 ksi steel Pure aluminum 5 ksi 13 ksi Al alloy 2024-T4 47 ksi 68 ksi

10. Al alloy containing 4.4% Cu (say 2024) can be heat treated to strength level much higher than that of pure Al So, does alloying affect the properties? Yield strength Tensile strength Low-strength 30 ksi 60 ksi steel Pure aluminum 5 ksi 13 ksi Al alloy 2024-T4 47 ksi 68 ksi Yield strength Tensile strength Low-strength 30 ksi 60 ksi steel Pure aluminum 5 ksi 13 ksi Al alloy 2024-T4 47 ksi 68 ksi What’s this??

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

12. T4 designates a heat treatment (Al alloys only) "solution heat-treated, quenched, and naturally aged to a substantially stable condition" T4 designates a heat treatment (Al alloys only) "solution heat-treated, quenched, and naturally aged to a substantially stable condition" How do we know this works?…….& why does it make the material stronger?

13. How do we know it works? We consult a road map for the material system How do we know it works? We consult a road map for the material system A portion of the Al-Cu "phase diagram" A portion of the Al-Cu "phase diagram"

14. We have a nomenclature problem

15. A new concept - the solid solution

23. A single phase Cu-Zn alloy is formed Then, where are the Zn atoms??

24. Assignments for next class: 1. review today's classnotes; know aluminum alloy designation schemes; know what a phase is; where do the Zn atoms go? 2. check syllabus materials at: http://www.ems.psu.edu/~ryba/coursework/259/mat se%20259.html 3. Read more of chapter 6 Assignments for next class: 1. review today's classnotes; know aluminum alloy designation schemes; know what a phase is; where do the Zn atoms go? 2. check syllabus materials at: http://www.ems.psu.edu/~ryba/coursework/259/mat se%20259.html 3. Read more of chapter 6