What is the effect of certain elements in Powder metallurgy alloy like bronze(prealloyed), Mg, Ni, Mo and Zinc?

Certain alloying elements like Mg, Zn is used as impregnation or for liquid state sintering. These elements increases the surface tension at the powder boundary and helps in bonding as it has lower melting point

Ni and Mo may be required as per requirement like corrosion resistance and high temperature property. So, it will depend on the type of alloy.