Honing&Coating0 pages

Honing & Coating

Thermal spray coats in cylinder
bores of internal combustion engines
are high-performance materials of
the future. Energy efficient engines
with low friction, reduced length and
lower weight as well as lower production costs can be achieved due
to the new process chain for the
manufacture of cylinder bores. To
this end, the process chain includes
the following processes:

to modern internal combustion
engines with a high degree of
energy efficiency, low emission
and longevity is also made.
Principles of honing and
coating

An overall result of this process chain
is a marked reduction in friction,
which considerably contributes to
reducing fuel and oil consumption.
Therefore a considerable contribution

To achieve a high degree of adhesion
when coating, mechanical roughening
(pre-treatment) as a variant of
precision boring is required. Mechanical roughening is realized through
cutting processes and combined
processes consisting of cutting and
forming. The following PTWA
coating (Plasma Transferred Wire
Arc) works with a plasma light arc
in which the supply wire is melted
and then sprayed onto the cylinder
bore. This results in a hard, wearresistant, ductile and easy to hone
cylinder liner coating.

Structure after honing

Mechanical roughening

- Mechanical roughing, PTWA coating,
overspray jets and honing.
The objective of honing and
coating

After the thermal coating follows
the overspraying jets in which overspray particles are removed from the
casting surfaces below the coated
cylinder bore by means of a jets of
water. Expensive masking is
no longer required the process chain
is thereby ready for production.
The subsequent honing, a multiplestep precision machining process,
creates the frictionless surface with
a high degree of dimensional and
form accuracy in the cylinder liner
which is needed for the engine.

Principles of coating

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