As precision engineered materials,
metal powders are available in a great variety for fabricating a wide range
of products through the PM process.
Generally, powder mixes for compacting are prepared from three powder types.
The first type is admixed powder, in which elemental alloying powders (such
as copper, nickel, graphite, and tin) are added to base element powders (such
as iron or copper). The second type is partially alloyed powder, composed
of two or more elements with alloying additives that are diffusion-bonded
to the base powder during the powder manufacturing process. These powders
produce a heterogeneous microstructure with good dimensional control and
excellent as-sintered mechanical properties. The third type is prealloyed
powders, which are atomized from alloyed furnace melts such that each powder
particle has the same nominal composition throughout. Prealloyed powders
yield homogeneous phase constituents in the microstructure.
For a brief overview showing the scope of conventional materials, take a
look at these tables: