290 Prakt. Met. Sonderband 46 (2014) 
nanocomposites. Furthermore, a short overview about the effect of SPD on multiphase or 
composite materials is given in the first part of the manuscript. 
2. EXPERIMENTAL 
The materials, which are investigated in this study, are multiphase materials consisting in 
all cases of a Cu matrix with different amounts of a second phase (Fe, Co or Cr). The 
materials were HPT deformed at room temperature to the saturation regime where no 
further refinement of the microstructure takes place [4,5]. Detailed processing parameters 
can be found in [8-10]. The microstructures of the materials are characterized by scanning 
electron microscopy (SEM) using the energy dispersive X-ray (EDX) analysis system 
attached to the SEM, transmission electron microscopy (TEM) and X-ray diffraction (XRD). 
3D atom probe (3DAP) analysis is performed on a LEAP 3000X HR from Cameca® on a The sic 
selected sample of the Fe-Cu material and the software package IVAS 3.4.3 from strong 
Cameca® is used for reconstruction of the probed volume and data analysis. The sample values 
is measured with the following parameters: a temperature of 30 K and a laser pulse energy the mic 
and frequency of 0.3 nd and 200 kHz, respectively. Vickers microhardness measurements 
are additionally conducted to evaluate mechanical properties using a load of 500 g (HV0.5) 
across the radii of the disks and mean values are reported. 3.2 CH 
3.2.1 Xx 
3. RESULTS 
XRD ii 
3.1 BULK NANOCOMPOSITES BY HPT structul 
single | 
Table 1 gives an overview of the multiphase materials investigated in this study. The strain and f.c 
induced during HPT deformation leads to significant refinement of the initial coarse- the initi 
grained phases of the different materials. To give an example, the heavily deformed due to 
structure of a Co-Cu composite deformed for 25 revolutions by HPT deformation and sc 
(equivalent strain ev of 450) is shown in the TEM micrograph in Fig. 1. determi 
First, pe 
to stac 
Seconc 
broade 
well. If 
‘absent 
supers: 
322E 
EDX ar 
quantite 
large pl 
Cu spe 
limitatio 
Fig. 1: TEM micrograph showing the nanostructure of a Co-Cu multiphase material nanoco 
in the as-deformed condition (RT) after 25 revolutions of HPT deformation. the bu!