The document discusses the opportunities of additive manufacturing (3D printing) for creating new composite materials. It describes how additive manufacturing allows metal or thermoplastic matrices to be combined with ceramic aggregates to produce materials with optimized properties. Specifically, 3D printing can precisely distribute ceramic grains within a metal matrix during layer-by-layer melting. This enables properties like high compressive strength and hardness from the ceramic, combined with ductility and strength from the metal. Examples highlighted include knives with sand-like hardness and buildings with 10x greater load-bearing capacity. The document argues additive manufacturing of metal-ceramic composites could revolutionize industries like construction and defense.

1. The opportunities of additive
manufacturing (3D printing) in the
creation of the new generation of
composite materials
Dr. Andras Bela Olah

2. Additive manufacturing I.
According to the definition of additive manufacturing in
the final shape is not achieved through slivering a raw
material slug, but through „gluing”many small pieces of
raw material together.
There can be used many kind of raw materials. At the
beginning there were used thermoplasts due to their
relative low melting point and high chemical stability. The
term „3D printing” comes from that a prototype „plotter”
was made from an ordinary inkjet printer, but it used
melted thermoplast instead of ink.

3. Additive manufacturing II.
The basic method is building up an object from thin
layers. Creating such a single thin layer is very similar to
ordinary 2D ink layer printing.
The possible raw materials are mostly thermoplasts, but
in present days the usage of metal powder is also
possible.
In case of thermoplasts the 3D plotter melts the plastic
and the print head puts it to the appropriate place, where
it becomes solid and is glued to the layer beneath it.

4. Additive manufacturing III.
A thermoplast using ordinary 3D plotter with a ready
prototype.

5. Additive manufacturing (metals) I.
The additive manufacturing could be used only for modelling,
while the raw material was only thermoplast.
In present days the usage of metals as raw material is also
possible. The essence of the process is that the printed area is
electrostatically charged, then the whole printing area is
covered by a metal powder layer. After this there is a sudden
blowdown and due to it only the electrostatically charged
metal powder remains on the surface. The next step is melting
together the remained metal powder with a high energy laser.
Due to this it is melted together also with the metal layer
beneath it (the previous layer). On this way it is possible to
create metal objects with this technology.

6. Additive manufacturing (metals) II.
The first jet engine made by additive manufacturing.

7. Additive manufacturing (metals) III.
The opportunity of using metals as raw material
eventuates the sudden propagation of this technology in
the near future.
In the first time only precision metal tools will be made by
this technology, but later (as it becomes cheaper) almost
all kind of metal tools will be made on this way and the
traditional forging (CNC) will be out to date.
The cost of production is determined basicly by two
things: the cost of melting (the melting point of the
metal) and the cost of the metal powder itself. Naturally,
aluminium and iron/steel will be the two primary
raw material.

8. Composite materials I.
The composite materials are proper complex materials.
The great advantage of these stuffs that they unite the
positive attributes of the raw materials.
These advantageous features are typically different
mechanical attributes, or a further goal by creating
composite materials used to be the decreasing of weight.
Nevertheless weight decreasing and incorrodibility used
to be achieved by using alloys or alloying materials, so in
the following the increasing quality of mechanical
attributes will be emphasized.

9. Composite materials II.
The different mechanical attributes used to be on the one
hand is great hardiness and great compressive strength,
which used to be paired with brittleness and frangibility
(ceramics and glasses). On the other hand there are materials
with relatively low hardiness and compressive strength, but
having great tensile strength and resiliency (metals).
It is worth to mention that there exist so called cermets
(ceramic + metal) wich can unite these positive mechanical
qualities in their chemical structure. These are usually
chemical alloys (titanium-diboride, silica-borides). But they
are so expensive and the boron is so rare that they can not be
used in mass production.

10. Composite materials III.
The main difference between alloys and composites that
composites are not homogenous microscopically (typical
examples are concrete and ferroconcrete) as against alloys
especially chemical alloys, which even have chemical
formula (i.e. titanium-diboride TiB2).
The composites used to have two, or sometimes three
components. In case of concrete the aggregate and the
matrix is the two materials, in case of ferroconcrete there
is a third one, the iron mesh structure.

11. Composite materials IV.
The most well-known composite material: concrete.

12. Composite materials V.
Glass fiber strengthened plastic (resin). The goal was
unequivocally composing advantageous mechanical attributes.

13. Composite materials and additive manufacturing I.
In case of composite materials, when there is a matrix and
aggregate material(-s) the homogenous distribution of
aggregates is very important and there can occur great
problems on this point.
In case of ordinary concrete the mixing is not a problem
because the mixture of cement and water is a liquid with
high viscosity and this can be mixed very well with
aggregates. In case of thermoplast or resin matrices their
melting point is relatively low, or they contain some
liquifying materials, which can later evaporate, thus they
can be also easily mixed with aggregates.

14. Composite materials and additive manufacturing II.
The situation is quite different in case of metal matrices.
Among the widely used structural metals the aluminium
has the lowest melting point (660 °C) which is quite
advantageous in case of founding, but composing it with
aggregates needs a very expensive technological
background (there can not be imagined a mixer car with
this material temperature).
There must be mentioned that there exist such
technology, but it is very expensive and used only to
produce the composite (metal matrix and ceramic
aggregate) armor of modern tanks.

15. Composite materials and additive manufacturing III.
Modern british main battle tank with composite armor.

16. Composite materials and additive manufacturing IV.
The previously mentioned additive manufacturing with metal
raw materials can be easily adapted to composites:
There will be used also metal powder layers, but there will be
also used a ceramic powder (or grain) layer before the metal,
which can be kept there also electrostatically, thus the shaping
is not a problem.
During the melting process only the metal powder melts (it has
much lower melting point), so the metal will glue together the
ceramic grains and glue them to the beneath layers.
On this way there can be obtained a metal-ceramic composite
material with arbitrary shape and perfect grain distribution!!!

17. Composite materials and additive manufacturing
(opportunities) I.
The previously mentioned additive manufacturing method
can revolutionarize the product of such materials. It will
be the same revolution that happened in construction
after the invention of concrete, but in this case this will be
wider, because all kind of construction material (which
was by this time typically aluminium, steel, even
titanium or alloys) is involved.
The simpliest example is an ordinary knife. If it is made of steel
than its hardiness on the Mohs-scale is 4-4.4. If it is an
aluminium matrix - sand grain composite, then the hardiness is
that of the sand (6.5 on Mohs scale) and the other attributes is
that of the metal (and it is easier than steel).

18. Composite materials and additive manufacturing
(opportunities) II.
An other well-known example is the building structures. In
present days the greatest steel consumer is the building
industry. Currently, it is possible to build many 100 m tall
building structures from steel. At the same time, the greatest
disadvantage of steel is that it has relatively low compressive
strength.
Using additive technology and such composites, with steel or
aluminium matrices and sand or corundum aggregates, the
advantageous features of metals remained, but the
compressive strength can be increased in an order of
magnitude (≈ 10 km tall buildings!!!).

19. Composite materials and additive manufacturing
(opportunities) III.
Finally, military applications, possibilites:
With such a technology it is not hard to create a
composite, which matrix is titanium (basically, because
titanium has a little bit lower melting point than iron, and
chemically more stabile, it is a little bit easier, although the
cost of the raw material itself is greater).
In case the aggregate is silica-carbide, then there can be
obtained an almost diamond hard, arbitrarily shaped
material with the resiliency and tensile strength of
titanium, which can revolutionarize the whole defense
industry around the world!!!

20. Thank you for your attention!
Dr. Andras Bela Olah