Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Development of adherent ceramic coatings to reduce contact stress damage of ceramics

Technical Report ·
DOI:https://doi.org/10.2172/6623608· OSTI ID:6623608
; ;  [1]
  1. GTE Labs., Inc., Waltham, MA (United States)

Strongly adherent coatings were deposited on reaction bonded Si[sub 3]N[sub 4] (RBSN), sintered SiC (SSC), and HIP'ed Si[sub 3]N[sub 4] (HSN) and using a newly developed chemical vapor deposition (CVD) process. Performance of the coating was assessed by oxidation, strength and contact stress testing. A new method was developed to experimentally determine the strength and Weibull modulus of thin brittle films on ceramic substrates. A significant portion of the study was devoted to numerical modeling of the coatings in order to understand the contributions of residual stress as different coating materials and thicknesses were combined. Coating designs were further analyzed by simulating the crack growth behavior in multilayer films while accounting for the interface fracture mechanics. This work has shown that the Al[sub 2]0[sub 3+]ZrO[sub 2] composite coating developed in this program can provide resistance to oxidation and contact stress. Commercial application of the composite coating has been successfully demonstrated by useof the Al[sub 2]0[sub 3+]ZrO[sub 2] composite as a protective coating on a Si[sub 3]N[sub 4] cutting tool.

Research Organization:
Oak Ridge National Lab., TN (United States); GTE Labs., Inc., Waltham, MA (United States)
Sponsoring Organization:
DOE; USDOE, Washington, DC (United States)
DOE Contract Number:
AC05-84OR21400
OSTI ID:
6623608
Report Number(s):
ORNL/Sub-89-95915/2; ON: DE93012518
Country of Publication:
United States
Language:
English