Ceradyne Increases its
Range of Products to
the Automotive Industry
John Mangels and Edwin Belfield, Ceradyne, Inc., Costa Mesa, CA USA
C eradyne recently acquired two
new businesses; Quest Tech-
nology LP based in San Diego, Cali-
fornia and ESK Ceramics GmbH &
Co KG based in Kempten, Germany.
These two companies add compli-
mentary products in a number of
industrial, engineering, electronic
and medical areas, some of which
widen our portfolio of products and
solutions offered to the automotive
world and suppliers to the automo-
tive business.
Cam Rollers for Valve Train and
Fuel Systems
Ceradyne continues to explore new
engine environment applications for
Ceralloy® 147-31N Silicon Nitride,
particularly where increased fuel in-
jection pressures have given rise to
contact stresses beyond those sus-
tainable between two contacting
steel components.
Ceralloy® 147-31N Silicon Nitride is
a strong, tough, lightweight, wear
resistant ceramic material with
unique tribological and physical
properties (low weight combined with
high strength and contact fatigue
resistance) that allows its use under
high contact stress, often exceeding
300 GPa.
To understand the benefits of Ceral-
loy® 147-31N one must first under-
stand the failure mode of metal cam
rollers. A metal cam roller system for
heavy-duty diesel engines consists
of a steel roller with a bronze pin.
The metal roller runs against a steel
cam. Failure begins as the bronze
pin wears. The wear is accelerated
because bronze is a relatively soft
metal. The wear of the pin makes it
more difficult for the metal roller to
rotate. This then results in skidding
against the cam lobe and ultimately
scuffing, micro welding and galling of
both the cam roller and the cam
lobe. Fatigue failure will follow.
Higher contact stresses particularly
those generated at the fuel injection
cam operating unit pump injectors,
will accelerate the process.
The Ceralloy® 147-31N based cam
roller solution consists of a silicon
nitr