Ni3Al and NiAl pre-alloyed powders produced by argon gas atomization are investigated by light and transmission electron microscopy concerning their structure, chemical and phase composition. For example, Ni3Al powder consists of a L12 matrix (γ′ -phase) with precipitates whose Al content is 6% higher than in the matrix. Selected single powder particles were isothermally deformed in a modified high resolution dilatometer to investigate the creep behavior. From these experiments HIP parameters are predicted and compared with HIP experiments at different pressures and temperatures. HIP diagrams were calculated according to Ashby's model.