[townga]

What is the  formula for the reaction between aluminum cichromate and nickel (II) phosphate? What type of reaction is it?

[AWK]

Your problem is quite complex. Both copounds are insoluble in water so double exchange reaction rather do not take place.It is also difficult to predict if this reaction can proceed during sintering or melting. In this case also redox reaction (CrO₄^2- to CrO₂^- and Ni²⁺ to Ni³⁺) should be taken into account.