Particle shape:
Particles of powder can take the form of spherical, rounded, cylindrical, spongy, acicular, flaky, cubic and aggregated. As shown in figure 3.
Fineness:
Refers to particle size of powder, can be determined either by pouring the powder through a sieve or by microscopic testing. A standard sieves with mesh size varies between (100) and (325) are used to determine particle size and particle size distribution of powder in a certain range.
Particle size distribution:
Refers to amount of each particle size in the powder and have a great effect in determining flowability, apparent density and final porosity of product.
Flow rate:
The ability of powder to be transferred or the rate at which the metal powder will flow under gravity from a container through an orifice both having the specific shape and finish.
Chemical properties:
It usually reveals the impureties, amount of oxides and other elements that can be included in the powder.
Compressibility:
A measure of the powder ability to deform under applied pressure. It is defined as the ratio of the volume of powder poured into the die to the volume of the pressed compact. Compressibility is affected by particle shape and particle size distribution. Green strength (strength of compacted product before sintering) depend on compressibility.
