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ADVANCED MATERIALS & PROCESSES • FEBRUARY 2014 38
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The Journal of Thermal Spray
Technology (JTST), the official
journal of the ASM Thermal
Spray Society, publishes contri-
butions on all aspects—funda-
mental and practical—of
thermal spray science, including
processes, feedstock manufac-
ture, testing, and characteriza-
tion. As the primary vehicle
for thermal spray information
transfer, its mission is to syner-
gize the rapidly advancing thermal spray industry and related
industries by presenting research and development efforts
leading to advancements in implementable engineering ap-
plications of the technology. Articles from the October and
December issues, as selected by JTST Editor-in-Chief Chris-
tian Moreau, are highlighted. The December issue features
papers from the 2012 Asian Thermal Spray Conference, or-
ganized by guest editor Dr. Seiji Kuroda. The last two articles
highlighted below are from this special issue. In addition to
the print publication, JTST is available online through
. For more information, please visit
“Improved Thermal Cycling Durability
of Thermal Barrier Coatings
Manufactured by PS-PVD”
S. Rezanka, G. Mauer, and R. Vaßen
The plasma spray-physical vapor deposition (PS-PVD) process
shows promise for the manufacture of thermal barrier coatings
(TBCs). The durability of PS-PVD manufactured columnar TBCs
is strongly influenced by the compatibility of the metallic bond-
coat (BC) and ceramic TBC. Earlier investigations show that a
smooth BC surface is beneficial for durability during thermal cy-
cling. Further bond improvements between BC and TBC could be
achieved by optimizing the formation of the thermally grown
oxide (TGO) layer. In the present study, parameters of pre-heating
and deposition of the first coating layer were investigated in order
to adjust TGO growth. The durability of PS-PVD coatings was
improved while maintaining a much higher deposition rate in
comparison to EB-PVD. Improved thermal cycling lifetimes more
than two times higher than conventionally sprayed TBCs were
measured in burner rigs at ~1250°C/1050°C surface/substrate ex-
posure temperatures.
Scanning electron micrograph (back-scattered electron image) of
double-layer system with 50 lm APS layer.
“Tribological Characterization of
Plasma-Sprayed CoNiCrAlY-BN Abradable
Coatings”
E. Irissou, A. Dadouche, and R.S. Lima
Plasma spray torch parameters were varied to produce a set of
abradable coatings exhibiting a broad range of porosity levels (34-
62%) and superficial Rockwell hardness values (0-78 HR15Y).
Abradability tests
were performed using
an abradable-seal
test rig, capable of
simulating opera-
tional wear at dif-
ferent rotor speeds
and seal incursion
rates (SIRs). Tests
determined rubbing
forces and quanti-
fied blade and seal
wear characteristics
for slow and fast
SIRs. Erosion wear
performance and
ASTMC633 coating
adhesion strength
test results are also
reported. For opti-
mal abradability
performance, coat-
ing hardness needs
to be lower than 70
(a) General view of the abradable test rig.
(b) Close-up view of the test section.
JTST HIGHL IGHTS