a process for casting and preparing an ingot of a beta - phase nial - based material , particularly for use in pvd coating processes . the method entails melting a nickel - aluminum composition having an aluminum content below that required for stoichiometric beta - phase nial intermetallic so as to form a melt comprising nickel and ni 3 al . aluminum is then added to the melt , causing an exothermic reaction between nickel and aluminum as the melt equilibrium shifts from ni 3 al to nial . however , the aluminum is added at a rate sufficiently low to avoid a violent exothermic reaction . the addition of aluminum continues until sufficient aluminum has been added to the melt to yield a beta - phase nial - based material . the beta - phase nial - based material is then solidified to form an ingot , which is then heated and pressed to close porosity and homogenize the microstructure of the ingot .