Plasma Spraying's Advantages

       

You must heard of the plasma spraying. Do
you know the advantages of plasma spraying? Wococarbide provides tungsten
carbide powder to fit for plasma spraying.

Plasma spraying not only has the same
advantages as other spraying methods, such as unlimited part size, wide base
material, small machining allowance, and can spray and strengthen the surface
of common base material parts, but also has the following advantages:

(1) The substrate is little heated, the
parts are not deformed, and the heat treatment state is not changed.

Because the parts are not charged and the
base metal is not melted during spraying, although the temperature of the
plasma flame is high, the energy is very concentrated, and the axial
temperature gradient of the plasma arc is very large. Generally, if the
temperature rise of the parts does not exceed 200 ℃, the parts will not deform,
which is very beneficial for the repair of thin-walled parts, slender rods and
some precision parts. Because the heat treatment properties of the base metal
will not change below 200 ℃, some high strength steel can be sprayed.

(2) A wide range of materials can be
sprayed, and there are many kinds of coatings.

Due to the high temperature of plasma
flame, various spraying materials can be heated to the molten state. Therefore,
a wide range of materials can be used for plasma spraying, and spraying layers
with various properties can be obtained, such as wear-resistant coating, heat
insulation coating, high temperature oxidation resistance coating, insulation
coating, etc. As far as the universality of coatings is concerned, oxygen
acetylene flame spraying, arc spraying, high frequency induction spraying and
explosion spraying are not as good as plasma spraying.

(3) The process is stable and the coating
quality is high.

The process parameters of plasma spraying
can be controlled quantitatively, the process is stable and the coating has
good reproducibility. In plasma spraying, the flying speed of particles in
molten state can reach 180-480m / s or even higher, which is much higher than
that of particles in oxygen acetylene flame powder spraying of 45-120m / s.
When the molten particles collide with the parts, the deformation is
sufficient, the coating is dense, and the bonding strength with the substrate
is high. The normal bonding strength between plasma sprayed coating and base
metal is usually 30-70mpa, while that of oxygen acetylene flame spraying is
generally 5-20mpa. Because the atmosphere can be controlled by changing the gas
during plasma spraying, the oxygen or nitrogen content in the coating can be
greatly reduced.