In the present study, aluminium nitride (AlN) ceramics were
metallized by conventional Moly-Manganese (Mo-Mn) process in the temperature
range of 1200–1400oC for 20 min. The objective of the current study was to
evaluate the adherence of the metallized layer on aluminium nitride ceramic
surface by scratch test and pull-off test methods. Scratch testing is a simple
and fast method of evaluating coatings qualitatively. The adhesion of the
metallized layer with the substrate was evaluated by scratch testing technique
at different loads ranging from 5 N-25 N. During the scratch test a stylus was
moved on the sample surface with linearly increasing load. Optical microscopy
was utilized to examine the width of the scratch track. The scratch test
results showed that the metallization of AlN ceramics required a high
metallization temperature for the formation of an effective, uniform metallized
layer on them. The surface texture of the scratch track revealed that the width
of the scratch track enhanced with increasing applied load. It was evident from
the optical microscopy that during the scratch test, the material removal was
increased with increasing the applied load when the metallization temperature
was made constant while the material removal was decreased with the increase of
metallization temperature for a constant applied load. The adhesion of the
metallizing layer on the AlN ceramics was also evaluated quantitatively by a
pull-off test using a stud pull tester. The adhesion strength of metallized
(1400oC, 20 min) layer on the AlN substrate was 5 MPa at a force of 30.8 N.
Both the scratch test as well as pull-off test indicated that the Mo-Mn layer
metallized at 1400oC for 20 min showed the best adhesion strength.
Author(s)details:-
Dr. Shirshendu
Chakraborty
CSIR-Central Glass and Ceramic Research Institute, Kolkata-700 032, India.
Dr. Sumana Ghosh
CSIR-Central Glass and Ceramic Research Institute, Kolkata-700 032, India.
Please See the book
here :- https://doi.org/10.9734/bpi/cmsdi/v1/11989F
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