How you have confirmed the formation of Al3Ni intermetallics?

Yes, through both EDS and XRD analysis. I need to know where the eutectic point actually is for the alloy. I don't know how....

which technique is used for developing this alloy? is it die casting? Due to Melting pt. difference in Ni and Al, less amount of Ni is added in alloy. so I ask the question

We used master alloys. It is almost accurate Yaxil. Can anybody tell me where the Eutectic point of L--> Al+Al3Ni is for Al-12Zn-2.5Mg-2.5Cu alloy?

You can search Al-Ni phase diagram at ASM handbook Vol 3. Alloy phase diagram.

It shift to lower levels of Ni when other elements are introduced to the alloy (such as ZN, Mg or Cu). the exact weight percent of Ni for the eutectic point is what i am looking for.

ok. But have refer ASM Handbook 3.

That's the point. I have to calculate my own diagram! I cant use ASM

why u r not using ASM handbook?

or u can make model or phase analysis by quantitative metallorgraphy, u may get your answers.

Why not do a few simple cooling curve experiments to probe the eutectic point? It's a basic into MSE experiment and that is actually how they construct phase diagrams (theoretical approaches do exist, but experimental ones are the accurate method)

I completely agree with JP Xu

the point is that i can use DSC or DTA for thermal analysis, but they wont reveal the eutectic point for me. (they will show me the eutectic temperature, but not the chemical composition...). I even dont now the approximate composition to run some tests

If you have fixed the amount of Zn, Mg and Cu, may be you can't find the exact point of the eutectic point in the quaternari equilibrium diagram. You just can look for the minimum in temperature for that pseudo-binary equilibrium diagram, in others words, you can find the eutectic point for taht fixed condition, but it can exist another composition with lower fusion temperature for another amount of Zn, Mg and Cu.

True, but i need to find the point for my alloy

Really, I know what you mean. This is the more difficult issue in ternary and quaternari equilibrium diagram.

I don't know if you can use a theorical program in order to evaluate the approximate composition, and try to confirm doing some experiments.

Another way, is to look for the eutectic point for the system Al-Zn-Mg or the system Al-Zn-Cu and I think the eutectic point could be similar.

I can email you the articles in which the diagrams for Al-Zn-Cu-Mg alloys with various amounts of Ni were calculated. Thermocalc was used to draw the diagrams. So, It possible to obtain a diagram for Al-Zn-Cu-Mg alloy, with temperature as the vertical and Ni content as the horizontal axes (just like Al-Ni binary diagram)

So you posted this question 22 days ago, and still did not solve it. If you had tried to experimentally measure the phase diagram, it would take much shorter time. Sounds like you have not done experiments constructing phase diagrams, all you do is heat up the materials until they melt, and then simply put a t/c in them and let them cool down, it is a very easy measurement to do, and if this particular alloy is of interest to the community, you could/should publish your measured phase diagram too, people publish phase diagrams all the time, because they are important and useful to others. If you do not have any idea with where to start, then just start at the whole range, i.e. 0-100 / 20-80 / 40-60 / 60-80 / 100-0, therefore for this experiment all you need is: 1) alloys at different composition 2) a furnace 3) five crucibles 4) five thermocouples, 5) equipment to log temperature change vs time. And afterwards can do another set to narrow it down.

I totally understand you Xu. The thing is that I don't have enough time to do that. I must wrap up my thesis in a month or two! It 's not my priority to find this point, though it would help me justify my findings. in addition, it's gonna consume a lot of time and material to do these experiments. doing what u say would be a whole different project, maybe even an independent one!

what u suggest is quite complicated. I can simply use a thermocouple for alloys with 1 to 5 wt. % Ni and see which one has the lowest liquidous temperature. that would be the corresponding eutectic point. It would require like 10 melts to determine the point with an 0.5 degree error! what Do you think? do you think it would work?

Anyway, thanks for the comment.

If you know the eutectic point is between 1-5% then sure it should work. If you have limited supply, can just use one sample, being with measuring a cooling curve at 0%, then the next day add some Ni make it 1% and then test it again, etc.