Pictured below are photomicrographs of the two Cu-P alloys from the previous pag
ID: 1025280 • Letter: P
Question
Pictured below are photomicrographs of the two Cu-P alloys from the previous pages The dark phase in these microstructures is the alpha phase 20 um 20 um i- Identify which photo is the 92Cu-8P alloy and which is the 82Cu-18P. State how you know this ll-Region A in photo #1 is known as ? ii- Region A is darker in its center and lighter at its perimeter. Why? N-The composition of region B in photo #2 is ? v- Region C is the product of what reaction? vi - which of these two alloys do you think cooled the fastest? Why? vii-(Bonus) in photo #2, the line labeled D is a crack. Why is this alloy susceptible to cracking?Explanation / Answer
I. 1 is 92Cu-8P alloy. Because if P increases then the joining gap is too large and large numbers of voids will present in the free flowflo alloy.
2. Eutectic region melting area.
3. Because of flow rate of free moving alloy. At the Eutectic temparature sluggish melting we cac observe.
4. 82 Cu-18P alloy mixture
5. Dissolving process
6. 1 Is cooled slower than 2 bcz cracking is present in 2. Because of faster cooling crack will come.
7. Because of the fast cooling. But usually if amount of P increases then only cracking will be more and less ductile also. Here even P less also it is cracked because of fast cooling