What is Nickel Powder? Nickel powder is a dense metal powder that has many characteristics that make it difficult to sieve. Spherical nickel powder has the tendency to blind screens and can quickly overload a screen if not properly monitored. Non-spherical powder nickel tends to have a porous texture and looks almost like coral. This can be difficult to screen because many of the particles are high-aspect, angular and only fit through the screen hole in one direction.