JEC COMPOSITES MAGAZINE - Issue #102 - January/February 2016 - 32

phenolic

Composite materials ready to replace
aluminium in internal combustion engines

By
hendrik de keyser
MArketing And technology officer,
sBhPP high PerforMAnce PlAstics,
dr. lArs-fredrik Berg, reseArch AreA MAnAger,
jAnnik stAMMler Msc, reseArch engineer,
lightweight PowertrAin design,
frAunhofer Project grouP - new drive systeMs

In the next 3-5 years, the first cylinder housings manufactured from
polymer composite materials could be introduced into passenger car
and motorbike engines, replacing the aluminium components currently in use. Glass fibre-reinforced phenolic cylinder housings manufactured by injection moulding deliver the same performance as die-cast
aluminium components but offer a significant reduction in weight,
lower manufacturing costs and a better life cycle assessment. Additional benefits include reduced heat radiation, lower engine noise
emissions and the elimination of corrosion-related issues.

A range of candidate materials

C

ar makers are under increasing pressure from legislators to improve fuel
consumption and reduce CO2 emissions from their new vehicles. One way of
achieving this is to reduce vehicle weight:
lowering a car's weight by 50 kg improves
fuel economy by up to 2%, resulting in a reduction in carbon emissions of up to 5 g of
CO2/km. Much of this effort has been focused on integrating lightweight materials
into body parts, but the powertrain (which
includes the engine) also accounts for a
large proportion of a vehicle's weight. Until
now, vehicle manufacturers have relied on
switching from cast iron to aluminium to
reduce the weight of engine components
such as the cylinder block - the single
heaviest part of almost every car. It is now
possible to incorporate parts made of
polymer composites into cylinder blocks to
reduce weight even further. Since phenolic
composites have a much lower density than
aluminium (1.7 g/cm3 compared with 2.7
g/cm3), replacing aluminium parts with
composite will typically result in weight
savings of around 20-30%.

Research into the use of polymer composites in the engine block has been ongoing
since the 1980s and experimental engines
have been developed, but the manufacturing techniques used were not suitable for
mass production. Candidate materials are
glass fibre-reinforced epoxy and phenolic
composites, and carbon fibre-reinforced
epoxy composites, all of which are able
to withstand the extreme temperatures
and demanding chemical environment
under the bonnet. In terms of mechanical
performance and price, glass-reinforced
phenolics are a better choice for cylinder
housings than epoxies, and they can also

withstand higher temperatures. Carbon
fibre-reinforced epoxy is a lighter weight,
but more expensive, option. The choice of
material will depend on whether the car
maker's priority is weight or cost reduction.
As a market leader in phenolic moulding
compounds, SBHPP High Performance
Plastics, Belgium, a business unit of
Sumitomo Bakelite Co., Ltd., has been
developing thermoset composite parts for
the automotive industry for more than
20 years. A strategic focus is the engine
and the company has developed numerous under-bonnet applications, including turbocharger components, air intake
manifolds, water pumps and thermostat

Fig. 1: SBHPP has developed a phenolic composite cylinder housing for a single-cylinder 650 cc engine that
demonstrates a significant weight reduction over the aluminium part, as well as lower manufacturing costs

32 jec composites magazine / No102 January - February 2016
Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #102 - January/February 2016
