For the given heating and cooling curves of 4 Pb - Sn alloys, determine: 1 Liqui
ID: 497551 • Letter: F
Question
For the given heating and cooling curves of 4 Pb - Sn alloys, determine:
1 Liquidus Temperature 2 Eutectic Temperature 3 Solidus Temperature 4 Solidification (or freezing) range of alloy, 5 Melt Superheat (Initial melting temp - Liquidus) 6 Elapsed time at liquidus temp 7 Elapsed time at eutectic or solidus temp 8 Local solidification time (Elapsed time at Eutectic temp - Elapsed time at Liquidus Temp) 9 Solidification rate (Freezing range / local solidification time) Celcius/min 10 Composition of Alloy 11 Type of alloy (hypoeutectic, hypereutectic or eutectic) 12 Amount of eutectic at room temperature in this alloy 13 Type of primary phase in the alloy at room temperature 14 Amount of primary phase in the alloy at room temperature 15 Total amount of alpha phase in the alloy at room temperature 16 Total amount of Beta phase in the alloy at room temperature 300 250 200 150 100 50 200 400 Station A Heating 600 800 1000 1200 1400 1600Explanation / Answer
Solution:
1. Liquidus temperature = 250 C
2.Eutectic temperature = 175 C
3. Solidus temperature = 150 C
4. Solidification (or freezing) range of alloy = 140 C
5. Melt Superheat (Initial melting temp - Liquidus) = 182 C
6. Elapsed time at liquidus temp = 50 sec
7. Elapsed time at eutectic or solidus temp = 350 sec
8. Local solidification time (Elapsed time at Eutectic temp - Elapsed time at Liquidus Temp) = 140 sec
9. Solidification rate (Freezing range / local solidification time) Celcius/min = 250 C / 1380 sec = 0.18 C/sec
= 10.8 C/min
10. Composition of Alloy = @ 182 C melting point is Sn63Pb37
11. Type of alloy (hypoeutectic, hypereutectic or eutectic) = eutectic
12. Amount of eutectic at room temperature in this alloy = 180 C
13. Type of primary phase in the alloy at room temperature = eutectic alloy (II)
14. Amount of primary phase in the alloy at room temperature = 50 wt(%)
15. Total amount of alpha phase in the alloy at room temperature = C = 16 wt% Sn-84 wt% Pb
16. Total amount of beta phase in the alloy at room temperature = C = 97 wt% Sn-3 wt% Pb