FEATURES OF PULSED LASER RADIATION ACTION
ON A CERAMIC VOK71 SURFACE IN WATER
V. V. Kuzin,
M. R. Portnoi,
S. Yu. Fedorov,
and N. R. Portnoi
Translated from Novye Ogneupory, No. 8, pp. 43 – 46, August 2015.
Original article submitted June 29, 2015.
Results are given for an experimental study of pulsed laser action on an oxide-carbide ceramic surface with
single-coordinate treatment in distilled water. It is established that the production medium has a marked effect
on single track geometric parameters and new surface morphology. The results obtained make it possible to
choose laser action parameters with the aim of controlling high-density ceramic surface microstructuring.
Keywords: high-density ceramic, pulsed laser radiation, track, ablation, surface morphology.
Previously  the connection of production regimes for
pulsed laser action, accomplished in air, with the morphol-
ogy of oxide-carbide ceramic VOK71 surface, was analyzed.
For effective use of a laser method for material surface layer
modification it is also necessary to know the mechanism of
laser radiation reaction with a material surface in different
production media [2 – 4].
The aim of this experimental research is a study of fea
tures of pulsed laser radiation action on the surface of
VOK71 specimens in water.
The experimental procedure has been considered in de
tail in , and therefore subsequently only the main assump
tions are given. Experiments were performed for the case of
single coordinate treatment of tracks 4.5 mm long using a
production laser model U-15 (wavelength l = 1064 nm,
pulse duration t»7 nsec, focusing spot diameter d
» 40 mm).
Pulsed laser action regimes were varied within the limits: la
ser pulse power P 5 – 15 W, pitch s
of laser beam movement
over axis x 10–50mm, frequency f of pulse sequence from
10 to 100 kHz, number n of passes in bundle 1 – 30, number
of passes N in a treatment cycle 1 – 25. The specimens used
were 12.7 ´ 12.7 ´ 4 mm in size of oxide-carbide ceramic
VOK71 with an original surface roughness Ra = 0.1 mm,
which were placed in a vessel with distilled water. The water
layer thickness above specimen surface in each experiment
was 2 mm. Depth h and width b of a single track were mea-
sured using a Hommel Tester T800 polygraph-profilometer.
Morphology of the ceramic surface formed was studied in an
optical (Olympus BX51M) and scanning electron (TESCAN
VEGA 3LMH) microscopes.
In presenting and analyzing results obtained in this re
search they were compared with results obtained in .
RESULTS AND DISCUSSION
Experiments have shown that pulsed laser treatment of
ceramic specimens with laser pulse power P of 5, 10, and
15 W forms well defined single tracks (Fig. 1). It is seen that
with an increase in laser pulse power track width increases,
and even with treatment with 5 W track width considerably
exceeds the laser beam focused spot diameter. Tracks formed
as a result of ablation of a surface layer in water, have un
clear boundaries, which is particularly marked with P =5W
treatment. Track morphology formed in water with respect to
this index differs markedly from that of tracks created in air,
which have quite clear boundaries (particularly during treat
ment with overlap of laser beam spots).
Dependences are shown in Fig. 2 specifying the effect of
laser pulse power P on geometric parameters of a single track
Refractories and Industrial Ceramics Vol. 56, No. 4, November, 2015
1083-4877/15/05604-0394 © 2015 Springer Science+Business Media New York
FGBOU VPO Moscow State Technological University Stankin,