TPi October 2009

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October 2009 Tube Products International 47
Mater ialsTube and pipe
Silicon nitride ceramic for demanding components
CERADYNE’S Ceralloy® 147-31N silicon nitride exhibits a
combination of mechanical, thermal and electrical properties
that the company claims is not found in any other material.
These properties include exceptional wear resistance; light
weight (1/3 the weight of tungsten carbide); superior thermal
shock behaviour; electrically non-conductive; non-magnetic;
and low coefficient of friction against steel.
Silicon nitride parts are said to outperform metal components
by reducing part failure and consequent system down time.
Ceralloy silicon nitride components are produced in fully
dedicated facilities at Ceradyne manufacturing plants in
the USA and Europe, using patented compositions and
processing techniques. The technology uses inexpensive,
plentiful raw materials and time-tested, high volume ceramic
manufacturing processes.
Ceradyne’s lightweight, durable heat and erosion resistant
silicon nitride is suited to applications from aerospace to
automotive engines and industrial applications.
Ceradyne, Inc – USA
•
A component manufactured from Ceradyne’s silicon nitride S S
LAUNCHED in March 2009, Rilsan® HT
for extrusion is claimed to be the first
flexible high-temperature thermoplastic
to replace metal in high-temperature
applications.
Arkema has now also introduced Rilsan
HT injection resins, making the range a
complete polyphtalamide (PPA)-based
product line suitable for all process
technologies, ranging from extrusion to
blown or injection moulding.
Rilsan HT resins are up to 70%bio-based
and match the increasing environmental
commitment of many industries.
PPA-based injection resins in automotive
applications have increasingly replaced
metal parts as a way to optimise costs,
reduce emissions and weight, improve
fuel economy and extend car life.
However, the resins have previously
been difficult and costly to process
when compared to aliphatic high-
performance polyamides.
Rilsan HT is said to be the only PPA-
based injection resin that offers
processing characteristics similar to
those of aliphatic high-performance
polyamides.
With mould temperatures close to those
of PA12 and PA11, Rilsan HT can be
easily processed on standard injection-
moulding equipment using conventional
water-cooled temperature control. It can
also be processed in injection moulds
designed for PA12 and PA11 thanks to
similar mould shrinkage properties.
Unlike conventional PPA-based resins,
Rilsan HT has very low moisture uptake,
which provides multiple benefits in
manufacture and applications.
Low moisture pickup means that Rilsan
HT resin is easily stored and requires no
supplemental steps before processing.
Low moisture absorption makes the
resin easy to process and handle,
and imparts reliable uniformity to the
finished parts’ properties, which avoids
further downstream processing and
limits waste.
Arkema claims that Rilsan HT is the
only PPA-based injection resin that can
be easily spin-welded with aliphatic
high performance polyamides – a
completely new processing feature for
this material group.
This offers further component inte-
gration and addresses the enhanced
safety and emission standards of
pipe connections in fuel-conducting
systems.
Rilsan HT injection grades – glass-fibre
reinforced or formulated for conductivity
– are suited to metal replacement in
fuel system applications requiring low
permeation, low swelling and high
thermal resistance.
The suitability of the injection grade for
quick-connectors and other temperature
resistant parts extends to power-train
components including those integrated
with Rilsan HT flexible tubing.
Arkema – France
Arkema rounds out the Rilsan
HT for extrusion product line