Powder production is the first step in
manufacture of powder metallurgy, along with the continuous development and
improvement of the manufacture of powder metallurgy, in order to meet the
requirements of all walks of life of powder metallurgy, powder production
method and powder metallurgy products are more and more, and various properties
of the powder in the powder metallurgy manufacturing have following several:
properties of the powder consists of powder physical properties, chemical
composition, process, properties and powder structure, in which the powder
structure, including the internal structure and external structure. The
structure of the powder has a direct effect on the other properties of the
powder and the properties of the powder metallurgy products.
From the point of view of the external
structure of the powder, the powder particles have developed outer surface and
inner surface. The outer surface can be seen on the surface, including all of
the surface of the particle surface of the convex and concave parts and the
width of the depth of the crack. The inner surface of the inner wall of the
depth including more than the width of the cracks, joints and micro granules
and the outer surface of the connected pores and cavities etc..
From the internal structure of the metal
powder, and the majority of non metal particles are formed by grain
composition. May be single crystal particles, can also be a polycrystalline
structure. The actual structure of the particle is more complex than the same
crystal structure of dense material. Grain growth in powder production
conditions are not sufficient, polar crystals is not complete, will lead to the
original powder after crushing, grinding, grain deformation and destruction.
Will affect the quality and chemical composition of powder.
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