CarboMetal

1) Al / Cu@CNT CompositesCu@CNTs are integrated in Al-alloy matrix through high energy ball-milling.The mixed powders as well as the composites produced are veryhomogeneous. Young’s modulus, yield strength and ultimate tensilestrength have been increased by 4%, 29% and 30%, respectively.

Institutsteil Dresden

Leibniz Insitutefor Solid State andMaterials ResearchDresden, Germanya

Powder Metallurgy Route:

Spray-compacting Route: Sprayformed Al-CNT Billet

2) Cu / CNT CompositesAs-grown CNTs and conditioned CNTs are embedded in a copper matrixthrough ultrasonic supported dispersion and mixing, hot pressing and hotextrusion. Depending on the used CNT type and volume fraction theproperties can be tailored (electrical conductivity, yield strength, ultimatetensile strength and thermal conductivity). The wet dispersion methodbrought forward to Aluminum-CNT composites.Oxygen Silicium Chlorine

Bead-like SiO2/x structures are grown on CNTs by Atomic LayerDeposition (ALD) in the gas phase.

XPS measurements verifies deposition of SiO2/x.:

100 nm 10 nm

Next steps:

•Integration of SiO2/x

funtionalised CNT in metalmatrix•Realization of otherfunctional groups, e. g. TiO2

6

5

4

3

2

1

0

Referenz

IPP (Impact Powder Pump)PEAK injection technique forpowder injection and powder milling

IPP technique is not suitable for the deagglomeration ofCNTs Baytubes C70P and homogeneous merging withAluminiumpowder (AlSi /AlZn)

1) PEAK route 1: direct powder injection technique into the melt stream for Sprayforming

2) PEAK route 2: powder injection of conditioned powder with IPP technique

Project target:Sprayformed aluminium billetDiameter: 300mmLength: 1250mmWeight: 220kg

Intensive and fast mixing with HOSOKAWAtechnique of CNTs Baytubes andAluminiumpowder

Intensive mixing technique is not suitable forembedding the CNTs into the aluminium powderparticles

3) PEAK route 3: alternative powder compaction (SPS or HIP) of conditioned and milledpowder [SPS: Spark Plasma Sintering, HIP: Hot Isostatic Pressing]

Synthesis of Al- and Cu-coated CNTs (ElectrolessPlating Process / Chemical and Heat Treatments)

In order to transfer the outstanding properties of the CNTs to themetal matrix composite, it is necessary to disperse the CNTshomogeneously into the bulk of the matrix. Additionally a goodinterface CNT-metal is required. Different routes are necessary tosynthesise multi-walled CNTs coated with aluminium and copper. Bymodification of the surface of the CNTs with defects or functionalgroups we could vary the grade of the CNT coating.

Al@CNT Cu@CNT

Melting Route: Dispersion of CNTs in Liquid Metal

The intention is the dispersion of CNTs by stirring into molten metal. Result(up to now): Mixing of non-treated CNTs in molten material is difficult. Al-coated CNTs are easier to disperse. The tested cast samples showed onlysmall increase of hardness and strength. CNTs in the residues within themelting pot had no Al functionalisation examined by SEM.

Principle ofmelt/stirring-process

Tested ceramic stirrer

Atomistic Simulations of CNT - Metal Interactions

Molecular dynamics simulations are used toinvestigate the thermal conductivity of CNT-metal composites. In the case of a CNT,partially covered by Fe atoms, a dramaticreduction of the thermal conductivitycompared to pristine CNTs is found.

The binding strength between metals andCNTs is determined using quantum-chemicalmethods. The role of defects, functionalgroups and doping has been examined for theinteraction between Cu and CNTs. While thefunctional groups OH and COOH arechemically reduced by Cu, defects or dopingwith B significantly increase the bindingstrength between Cu-atoms and the CNT-lattice.

Reduction of OH-group ongraphene by a single Cu-atom

C

CuH O

Synthesis of SiO2/x-coated CNTs (Atomic LayerDeposition)

Neue metallischeHochleistungsverbundwerkstoffe

Functio

nalis

atio

nb

yC

NT

-coatin

gfo

rm

eta

lmattrix

Sim

ula

tion

CN

T-M

eta

linte

ractio

ns

Fa

bric

atio

np

roce

sses

for

CN

T-re

info

rced

me

talm

atrix

com

po

site

s