572 Prakt. Met. Sonderband 30 (1999) 
applied coatings and the substrates of the high-speed steels occurs a decreasing concentration of, 
respectively, titanium and nitrogen, and also carbon in case of the Ti(C,N) coatings, as the distance 
from the coating surface grows, and also 
of other elements occurring in steels. 
This may indicate that slight mixing of 
elements, resulting from diffusion and 
connected with ion implantation, 
influences adherence of coatings apart 
from adhesion. 
The critical load Lc values, 
characterising the adherence of the 
investigated coatings to the substrate 
from the investigated high-speed steels, 
resulting from the adhesion forces, were 
determined using the scratch test. The 
critical load was determined as relating to 
the increase of the acoustic emission 
a indicating start of spalling of the coating. 
’ x 0.200 prdiv Investigations of scratches obtained 
0.8 Z 10.000 nw/aiv during the test were made on the 
HY dan120.02 scanning electron microscope to 
Fig. 4: AFM image of surface topography for TiN determine the character of the failure 
coating responsible for initiation of the increase 
of the acoustic emission. Adherence of 
coatings to their substrates from the high-speed steels evaluated basing on the scratch test is good. This 
is indicated by the critical load Lc values of, respectively about SON for the TiN coatings and about 
38N for the Ti(C,N) ones. Failure caused by movement of the penetrator with a variable load begins 
from the arc shaped cracks of coatings, changing to single spallings and chips on the bottom of the 
developing scratch and is connected with occurring of the crater shaped chipping, sometimes 
connected with the local delamination of fragments of coating. Mechanism connected with coating 
fragmentation dominates with high loads, due to plastic deformation of the substrate, demonstrated by 
origination of the characteristic semicircles. Development of these processes is slower in case of the 
TiN coatings than with the Ti(C,N) ones in spite of the increased loads. Total delamination of coatings 
does not occur, which also indicates to their good adherence to the substrate from the high-speed steels. 
Microhardness of the coatings was measured with 
the 5g load with the dynamic method at 
nanoindentation. This hardness was about 2300DHV 
for the titanium nitride TiN and about 2650DHV for 
the titanium carbonitride coating Ti(C,N). No 
influence of the substrate material was found out on 
the measured hardness. Hardness of the obtained 
coatings decides their erosion resistance. Therefore, 
the Ti(C,N) coatings demonstrate more than double 
erosion resistance compared to the TiN ones. Erosion 
failure of the heat treated high-speed steels in 
conditions ensuring their maximum secondary 
hardness consists in the uniform removal of the 
successive micro layers of material by micro Lig 3: SEM image of damage created due 
machining leading to origination of a crater. In case of tO erosion test of the Ti(C,N) coating 
the high-speed steels covered with both TiN and