1. MSE 201 LAB II: Part b Annealing Copper Alloys

2. Lab Overview Each alloy (Pure, 5% Zn, 10% Zn, 20% Zn) will be annealed for 45 minutes at 8 temperatures: Each alloy (Pure, 5% Zn, 10% Zn, 20% Zn) will be annealed for 45 minutes at 8 temperatures: 200°C, 250°C, 300°C, 350°C, 400°C, 500°C, 600°C, and 800°C Hardness after each anneal will show amount of recrystallization or grain growth Hardness after each anneal will show amount of recrystallization or grain growth PROCEED TO FURNACE ROOM TO CONDUCT ANNEALING PROCEED TO FURNACE ROOM TO CONDUCT ANNEALING

3. What is Recrystallization? Recovering damage and forming new grains by addition of heat Recovering damage and forming new grains by addition of heat (click to play)

4. Stages During Annealing I: Recovery I: Recovery II: Recrystallization II: Recrystallization III: Grain Growth III: Grain Growth

5. Goal: Plot of Hardness vs. Annealing Temp I: Recovery II: Recrystallization III: Grain Growth

6. Joined Plots Hardness vs. %CW and Annealing Temperature

7. http://www.copper.org/resources/properties/microstructure/brasses.html Stress Free Grain Grain Boundaries Etch Pits Annealing Twins

8. http://www.copper.org/resources/properties/microstructure/brasses.html

9. Slip Lines Deformation Bands Distorted Grains

10. New Crystal Formation

11. Microstructure Examination 5% Zinc samples will be examined 5% Zinc samples will be examined Sample 242: Shows effects of % cold working Sample 242: Shows effects of % cold working Sample 243: Shows effects of annealing temperature. Sample 243: Shows effects of annealing temperature. Look for: Look for: –Grain Boundaries –Stress Free Grains –Distorted Grains –New Crystals –Deformation Bands –Slip Lines –Annealing Twins –Etch Pits –Scratches

12. After Removing Samples… Remove oxide scale with sand paper Remove oxide scale with sand paper Average hardness results for each sample (HRF/HRB) and convert to DPH Average hardness results for each sample (HRF/HRB) and convert to DPH Make sure data sheet is completely filled out Make sure data sheet is completely filled out Place samples in recycle box. Place samples in recycle box. Turn Data Sheet in to TA Turn Data Sheet in to TA Remember: There is a report DUE NEXT WEEK!