I think atmospheric pressure needed and you can see the ternary phase diagram and compare the quantities you need with the solubility boundaries.

And I suggest you to use powder metallurgy technique by using the powders of these metals to get best results

The problem is not in melting point but the solubility of Ni and Cr in Al matrix which is quite low. How much of Ni and Cr you want to add into Al?

Thanks dear Cios:

The added quantity is(for example) 3.827 wt.% Ni , 0.337 wt.% Cr , into 95.836 wt.% Al

Thanks for the help dear Peng:

and what about the second part of the question

Solid solubility of Ni in Al is much smaller than take a look here: https://www.jstage.jst.go.jp/article/jilm/57/4/57_4_157/_article/-char/en

In case of chromium the situation os slightly better for binary Al-Cr: http://extras.springer.com/2006/978-3-540-43534-1/004000012A/papers/004000012A/004000012A0084.pdf

Thanks everyone

Dear Prof. Foaad,

you don't need pressure for this purpose , just the atmospheric pressure. you can use graphite crucible.

Best regards

Thank you dear Haneen

I think atmospheric pressure needed and you can see the ternary phase diagram and compare the quantities you need with the solubility boundaries.

And I suggest you to use powder metallurgy technique by using the powders of these metals to get best results