.Magnalium is a metal alloy (not the same as mixing Aluminum powder and Magnesium powder at the given ratio) composed of approximately 44% Aluminum and 56% magnesium.
Production requires the appropriate quantities (according to the 44:56 compositional ratio) of the two elemental metals to be heat to the point of transitioning to their liquid state, then mixed, sealed in the mixing vessel, and then cooled to room temperature.
The resulting solid block of magnalium alloy is then crushed, and ball milled into a powder. The resulting powder is then sieved to remove particles larger than the selected Mesh Grade.
This metal powder’s particles are thin, flat, and platelet-lIke in shape. Often referred to as “Flake” shaped.
Flake particles differ from the more commonly found spheroidal (atomized) particle metal powders, in that Flake type particles have a high diameter-to-thickness ratio (roughly from 40:1 to 100:1), and a large surface area to mass ratio (> 10 m²/g).
Particle shape, in metal powder’s, is an extremely important variable because of its impact on a pyrotechnic compositions reactivity. Think about it. Which is easier to light, a 3 x 3-inch piece of paper or a 3 x 3-inch piece of plywood? Chemically they’re almost the same thing. But the little, bitty edge of the paper is a lot easier and faster to light than the edge of the plywood. And that’s what separates the flake particles, from the atomized and spheroidal, ease of ignition.
No matter what type of exothermic reaction you are trying to produce, success will depend (in part) upon selecting metal powder products with the right particle shape specifications.
No matter what type of exothermic reaction you are trying to produce, success will depend (in part) upon selecting metal powder products with the right particle shape specifications.
Physical Structure of Particles & Dimensions
**”Flake” shaped particle powders are required, for the production of exothermic/reactive (pyrotechnic) compositions, compounds, and mixtures.
Because of the ball mill production process we use, all Ivy Tech and Metal Works metal powders are composed of “Flake Particles”.
Mesh (Particle Size Grade): Denotes the particle size of the screen which that grade of powder was sieved through. “Mesh Number” is interpreted in relation of the characteristics of the sieving screen. The mesh number = the number of holes in a 1 inch by 1 inch square area of a given sieve screen.
(Example: A 100 mesh screen, has 100 holes per 1 inch square area.)
So a Metal Powder having a designation of 100 mesh, means that all particles larger than those that fall through a 100 mesh sieve screen, have been removed.
