A material is characterised by its composition and its microstructure and both are very important.
The composition defines the name of the material and is linked to all alloy elements, and powder metallurgy is not different than other type of elaboration route on this theme. The only difference is that powder metallurgy materials are always very clean and allow high chemical properties. Compared to rod used for machining, the material is not dopped to enhanced machinability. Inclusions are always smaller than the powder size (ie super fine) and make this kind of metallurgy ideally suited for welding, polishing or products that need high resistance to corrosion.
Microstructure defines the behaviour of the material in use. Despite the fact it is extremely important, this is not always normalised and is not part of the name of the material. To compare two metals, it is mandatory to compare their composition but also their microstructure. Microstructure is due to the elaboration route and post treatments. Powder metallurgy produces fine grained materials with an isotropic annealed type structure. Complex machining can be performed due to the lack of internal residual stresses. Heat treatments are possible exactly as with conventional metallurgy and they are homogeneous due to the isotropy of the microstructure. Fatigue properties are always very good due to the fine grained structure, the lack of defects, the good surface definition and no skin effect.