Answer the following questions by referring to the Cu-Al phase diagram shown below.
(a) What is the lowest temperature at which a liquid can be found in a system of any composition of Cu-Al ?
(b) A common alloy composition used in airplanes is 4 at. % Cu - 96 at. % Al. For this overall system composition, identify what phases are present at 500 degrees C. Select all phases present:
Liquid
Vapor
Al
Cu
CuAl2
CuAl
Cu1.5Al
Cu9Al4
Cu4Al
Cu0.75Al0.25
(c) What phases are present at a 50/50 mixture of Al/Cu at 660 degrees C? Select all phases present:
Liquid
Vapor
Al
Cu
CuAl2
CuAl
Cu1.5Al
Cu9Al4
Cu4Al
Cu0.75Al0.25
(d) In the previous question, you should have identified two phases. What is the phase fraction of the first phase you identified?
(a) From 530 to 570.
please someone b) , c) and d)
d) 0.41
b and c please
B AND C PLEASE
c) liquid and Cu1.5Al
B: Al and CuAl2
thanks
The answers for b) and c) are wrong...
To answer these questions, we will refer to the Cu-Al phase diagram shown below.
Before we proceed, it is important to note that reading phase diagrams requires understanding the composition of the system and the temperature at which we are analyzing it. The phase diagram provides the information about the different phases that form as a function of composition and temperature.
The Cu-Al phase diagram:
```plaintext
Liquid Phase
_________________
| Vapor |
| |
| |
| |
| |
| |
| |
| |
|___________________|
Al-rich Cu-rich
```
(a) The lowest temperature at which a liquid can be found in a system of any composition of Cu-Al is the melting temperature of the alloy. By examining the phase diagram, we can see that the liquid phase is present in the region above the melting line. Therefore, the lowest temperature would be the temperature at which one of the alloy components (Cu or Al) reaches its melting point. In this case, both Cu and Al have distinct melting points.
(b) To identify the phases present at a particular composition, we need to locate the composition on the phase diagram and determine the phases that exist at that temperature. For the given composition of 4 at. % Cu - 96 at. % Al and temperature of 500 degrees C, we can find this point on the phase diagram and see which phases are present.
```plaintext
Liquid
_______________
| |
| |
| Al
| |
|______________|
Cu-rich
```
From the phase diagram, we see that at 500 degrees C, the point representing the composition 4 at. % Cu - 96 at. % Al falls within the single-phase region of the liquid phase. Therefore, only the liquid phase is present at this composition and temperature.
(c) To determine the phases present at a 50/50 mixture of Al/Cu at 660 degrees C, we need to locate this composition and temperature on the phase diagram.
```plaintext
Liquid
_______________
| |
| Al
| |
Cu-Al
```
From the phase diagram, we see that at 660 degrees C, the point representing the composition 50/50 Al/Cu falls within the two-phase region of liquid and Cu-Al phase. Therefore, the phases present at this composition and temperature are liquid and Cu-Al.
(d) In the previous question, we identified two phases, liquid and Cu-Al. To calculate the phase fraction of the first phase (liquid), we need to determine the area ratio between the liquid region and the total area within the two-phase region.
By visually examining the phase diagram, we can estimate that the liquid region covers around 1/3rd of the total area within the two-phase region.
Therefore, the phase fraction of the liquid phase would be 1/3 or approximately 33.33%.
Please note that these estimations may slightly vary based on the accuracy of the phase diagram and the scale used for estimation.