1. Examination and Failure Analysis of Annealed Paperclip By William Burgess and Khalid Mansour

2. Annealing Processes Annealing: Heat treatment wherein the microstructure and the material properties are altered. Annealing: Heat treatment wherein the microstructure and the material properties are altered. Samples separated using a vice-apparatus, applying a uniaxial load. Samples separated using a vice-apparatus, applying a uniaxial load. All samples where heated above the austenization temperature, then cooled differently. All samples where heated above the austenization temperature, then cooled differently. Samples where 1)Air cooled, 2) Furnace Cooled, 3) Quenched and 4) Tempered (~371 o C). Samples where 1)Air cooled, 2) Furnace Cooled, 3) Quenched and 4) Tempered (~371 o C).

3. Microstructure Preparation Heat and compress sample [Buehler Mounting Press]. Heat and compress sample [Buehler Mounting Press]. 4-Stage coarse Polish [Buehler]. 4-Stage coarse Polish [Buehler]. 2-Coarse fine artificial diamond polish with alumina (Al 2 O 3 ). 2-Coarse fine artificial diamond polish with alumina (Al 2 O 3 ). 3% Nitric Acid (97% ethanol) etching. 3% Nitric Acid (97% ethanol) etching. Alcohol swiping, cleaning. Alcohol swiping, cleaning. Investigate under optical microscope [Nikon optiphot 300]. Investigate under optical microscope [Nikon optiphot 300].

4. SEM Preparation Positioning samples on SEM apparatus. Positioning samples on SEM apparatus. Gold and Argon Sputtering (~5 nm) for conductivity [Cressington Gold Sputter Coater]. Gold and Argon Sputtering (~5 nm) for conductivity [Cressington Gold Sputter Coater]. Place sample on SEM, 20 kV accelerating voltage [Jeol Model JSM 35C]. Place sample on SEM, 20 kV accelerating voltage [Jeol Model JSM 35C].

5. Higher-Magnification Comparisons

6. 200x Magnification Comparison

7. Microstructure Analysis The softer the material, the larger the grain size. The softer the material, the larger the grain size. In order of softest to hardest: Furnace Cooled, Tempered, Air Cooled, Quenched. In order of softest to hardest: Furnace Cooled, Tempered, Air Cooled, Quenched. Mostly composed of Pearlite with quenched being fine pearlite, and more of the coarse pearlite as hardness decreases. Mostly composed of Pearlite with quenched being fine pearlite, and more of the coarse pearlite as hardness decreases.

8. SEM Analysis In general, the brittle fractures will have cleavage features (sharp edges, jagged, fig 8.41,p.231) and the ductile will have dimples (Round crater-like appearance, fig. 8.4a, pg. 196) on the SEM level. In general, the brittle fractures will have cleavage features (sharp edges, jagged, fig 8.41,p.231) and the ductile will have dimples (Round crater-like appearance, fig. 8.4a, pg. 196) on the SEM level. Difference in hardness if shown in the fracture surfaces: The quenched sample will have most cleavage, and the furnace cooled will have the most dimples. Samples will have a combination of both brittle and ductile characteristics. Difference in hardness if shown in the fracture surfaces: The quenched sample will have most cleavage, and the furnace cooled will have the most dimples. Samples will have a combination of both brittle and ductile characteristics. The surface of a brittle fracture will be rather flat and perpendicular to the axis of the applied load; the ductile will neck. The surface of a brittle fracture will be rather flat and perpendicular to the axis of the applied load; the ductile will neck.

9. SEM Quenched Sample

10. SEM Air Cooled Samples

11. SEM Tempered Sample

12. SEM Furnace Cooled Samples

13. Shout outs Said Mansour, for use of OCLI laboratory, information, and consultation. Said Mansour, for use of OCLI laboratory, information, and consultation. Eric Edler(technician), for assistance with the SEM images. Eric Edler(technician), for assistance with the SEM images. Cliff Alopa (physicist), for optical microscope assistance. Cliff Alopa (physicist), for optical microscope assistance. Younes, for assistance in annealing and preparing specimen; for materials- science wisdom. Younes, for assistance in annealing and preparing specimen; for materials- science wisdom.