Hence, the abrupt vanish of friction illustrated the pinhead did not put pressure on the specimens and the failure of
the coating happened. For the coated specimens without and with
CNTs, the first obvious vanishes of friction were detected at 2.04
and 3.22 N, respectively, as displayed in Fig. 7b, which were in
approximation with the results of acoustic emission scratch test.
The enhancement of interface bonding strength could be con-
tributed to the CNTs firmly rooted in C/C–ZrC–SiC substrates.