1. MatSE 259 Exam 1 Review Session 1.Exam structure – 25 questions, 1 mark each 2.Do NOT forget to write your student I.D. on the answer sheet 3.Exams are sent to UTS for machine grading – please mark your answers clearly. No credit will be given if the machine cannot decipher your score

2. Steel designation AISI-SAE numbering system for steels XX Percent carbon (wt) x 100 Alloy content For example, 5060 has ???

3. Aluminium alloy designation Numbering system for Al alloys not the same as steels 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 Numbering system also includes heat treatments – see website

4. Mechanical Properties Change due to; C content in steel Alloying elements Heat treatment - annealing, normalizing, tempering… Mechanical working - cold rolling, hot rolling, STRUCTURE changes

5. Phase Diagrams Differentiate between “phase” and “state” Phase diagram is a plot showing the relationship between temperature, composition and the quantities of phases in a system. On a phase diagram, you should be able to understand simple heat treatments, like the T4 studied in class. For example, Al 2024-T6.

6. Mechanical properties Tensile testing Elastic deformation – Plastic deformation – Yield Hooke’s Law Hardness testing Penetration by indenter under load Types – Rockwell, Brinell, Vickers, Knoop, Mohs Hardness-strength conversion

7. Mechanical properties (contd.) Impact Fracture testing Charpy and Izod Ductile-to-brittle transition Creep testing Primary, secondary, tertiary Steady-state creep rate Fatigue testing S-N curves Fatigue limit, fatigue strength, fatigue life Investigation of the fracture surface for the origin of crack “Chevron’’, striations, beachmarks

8. Dislocations Dislocations move along slip planes – ductility It is possible to plastically deform a material which contains dislocations

9. Crystal Structures Most common crystal structures for metals are: -Cubic close-packed -Hexagonal close-packed -Body centered cubic close-packed; most densely packed Slip planes are the most densely packed planes in these structures.

10. Dislocations The ability of a metal to deform depends on the ability of the dislocation to move Restricting dislocation motion will strengthen the material; - solid solution hardening - grain size reduction - strain hardening (work hardening) - precipitation hardening (age hardening)

11. Dislocations Interactions With each other - annihilate - entangle - form generators With grain boundaries - disappear - pile-ups