The need to reduce the weight of vehicles while enhancing
performance is at the heart of automakers interest in graphene,
IM heard at the Graphene 2017 conference in
Barcelona, Spain in April.
Addressing delegates, Vito Lambertini, head of materials
innovation at Centro Ricerche at automotive manufacturer
FIAT-FCA (Fiat Chrysler Automobiles), said that the need to
comply with emission regulations and to reduce the carbon
footprint of vehicles on the road means that producers have to
look to alternative materials to improve the
weight-to-performance profile.
"Cost is one of the main drivers that affect production [for
FIAT and other automakers] […] and weight is one major
focus," Lambertini said in Barcelona.
The weight of cars has increased significantly in recent
years as new components were added to improve safety and expand
functionality, he said.
A FIAT Tipo built in 2016 carries 20% more weight –
equivalent to 300kg – in its engine system compared
with a FIAT Ritmo of 1978. Its weight is also 30% higher as
regards body and chassis (+380kg), while it doubled against the
older model in electronic components (+100kg) and interior
components (+310kg).
"So you have much heavier cars today, while emissions have
decreased," he said.
A FIAT Bravo from 2009, he showed, consumes 29% less fuel
than the same model build in 1999.
The environmental-related concerns at an international level
regarding vehicle emissions are behind much of the work done by
producers to cut the carbon impact of their products.
|
| A 1978 FIAT Ritmo and a 2016 Tipo. While
the weight of vehicles has increased over time, emission
levels have declined. Netcarshow;
Flickr\smoothgroove22 |
In the case of Europe, EU-wide regulations setting emission
thresholds and long-term targets are forcing companies to plan
ahead to stay within the targets. Current emission thresholds
are set to be reduced further by 2020, and again by 2025, which
means producers have to work today to have their vehicles ready
by the time the regulations change.
"This is a key driver. Now you have to contain weight so you
can cut fuel consumption and, thus, emissions," said
Lambertini. "The other [driver] is customer demand, in terms of
style of the vehicle and personalisation."
FIAT is investigating how it can use graphene in its
materials as a way to help reduce the weight of vehicles.
Graphene-based polymers are one such area that is being
looked at. Considering that about 14% of cars is made of
polymeric materials (some 200kg), the company believes there is
scope to reduce that with alternative materials.
FIAT has tested smart electrically conductive polymer-based
components in wirings, electrical circuits, sensors and
switches, as well as parts of the car’s dashboard.
By using graphene polymers, due to graphene’s high
conductivity, such parts could be assembled without copper
cables.
"We can achieve metal wiring substitution in this way. This
leads to weight reduction as well as cost reduction, if you
think that there are about 2.5km of copper cables in your
average car," he said.
Other testing has been carried out in anti-corrosive
graphene coatings, and under-hood plastic components.
The challenges that the company sees at this stage in the
potential use of graphene as a material component are down to
the costs related with using the material – sourcing
as well as further processing costs required – and
manufacturing optimisation, he added.
Aerospace
The aviation industry is also looking to replace
conventional, metal-based material, with lighter and more
performing options, according to Maria Rodriguez Gude from
Spanish nanomaterials and composites producer FIDAMC.
In the case of aerospace, the core of the interest is in the
use of fibre-reinforced composites (CFRP), due to their
stiffness and strength and lower weight compared with metallic
structures.
"The aim is to obtain CFRP that not only are lightweight but
also improve mechanical performance, functionality, health
monitoring and surface technology," Rodriguez Gude said.