Development of thermal spraying technology

       

Thermal coating materials have the
advantages of fast deposition speed, high flexibility, easy automatic
processing and strong adaptability. Thermal spraying technology uses heat
source to melt the coating material onto the substrate material.

Thermal spraying technology with different
methods and uses was born in different years

1910: wire flame spraying technology; Flame
spraying of wire rod is widely used to prepare corrosion-resistant and
wear-resistant coatings on the surface of mechanical parts, chemical containers
and rollers. It can also be used to spray plastic powder after changing the
nozzle of spray gun. The arc wire spraying technology in the 1920s has the
following characteristics:

(1) The steel components are sprayed with
special and aluminum coatings for long-term protection.

(2) Spraying aluminum on steel parts can
prevent high temperature oxidation.

(3) Spray stainless steel or other wear-resistant
metal on iron and steel parts for wear and corrosion protection.

(4) Apply carbon steel, bronze and other
materials on the mechanical parts to repair the parts.

(5) Spray shielding coating on plastic
products.

(6) Composite copper plate is produced by
arc spraying aluminum or spray casting.

50's explosion spraying and plasma spraying
technology: high temperature plasma arc flame, suitable for spraying high
melting point materials. The density of the coating can reach 85-98%, the
bonding strength can reach 35-70mpa, and the spraying quality is much better
than that of flame spraying. Mainly used for:

(1) Wear resistant and anti-wear coating;

(2) Corrosion resistant coating;

(3) High temperature oxidation resistance,
high temperature airflow erosion resistance, thermal barrier coating;

(4) Manufacturing metal and ceramic
composite materials with high soldering point.

At present, thermal coating has become one
of the key technologies of high performance aeroengine manufacturing. In
addition, according to foreign statistical reports on the application of
high-performance ceramic coating, thermal spraying ceramic coating accounts for
two-thirds of the high-performance ceramic preparation market in North America,
which is basically consistent with domestic reports that the output value of
thermal spraying is about one-third of all the output value of surface
technology, indicating that thermal spraying technology has become one of the
important surface engineering technologies.

The spray material is melted by heat
energy, and then atomized by high-speed air flow. Driven by the high-speed air
flow, the particles impact the surface of the substrate and condense to form a
functional coating, which is called thermal spraying technology.