skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on February 27, 2018

Title: Fatigue behavior of thermal sprayed WC-CoCr- steel systems: Role of process and deposition parameters

Thermal spray deposited WC-CoCr coatings are extensively used for surface protection of wear prone components in a variety of applications. Although the primary purpose of the coating is wear and corrosion protection, many of the coated components are structural systems (aero landing gear, hydraulic cylinders, drive shafts etc.) and as such experience cyclic loading during service and are potentially prone to fatigue failure. It is of interest to ensure that the coating and the application process does not deleteriously affect the fatigue strength of the parent structural metal. It has long been appreciated that the relative fatigue life of a thermal sprayed component can be affected by the residual stresses arising from coating deposition. The magnitude of these stresses can be managed by torch processing parameters and can also be influenced by deposition effects, particularly the deposition temperature. In this study, the effect of both torch operating parameters (particle states) and deposition conditions (notably substrate temperature) were investigated through rotating bending fatigue studies. The results indicate a strong influence of process parameters on relative fatigue life, including credit or debit to the substrate's fatigue life measured via rotating bend beam studies. Damage progression within the substrate was further explored bymore » stripping the coating off part way through fatigue testing, revealing a delay in the onset of substrate damage with more fatigue resistant coatings but no benefit with coatings with inadequate properties. Finally, the results indicate that compressive residual stress and adequate load bearing capability of the coating (both controlled by torch and deposition parameters) delay onset of substrate damage, enabling fatigue credit of the coated component.« less
Authors:
 [1] ;  [1]
  1. Stony Brook Univ., NY (United States). Center for Thermal Spray Research
Publication Date:
Report Number(s):
SAND-2017-0715J; SAND-2016-9625J
Journal ID: ISSN 0257-8972; PII: S0257897217302165
Grant/Contract Number:
AC04-94AL85000
Type:
Accepted Manuscript
Journal Name:
Surface and Coatings Technology
Additional Journal Information:
Journal Volume: 315; Journal Issue: C; Journal ID: ISSN 0257-8972
Publisher:
Elsevier
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
Stony Brook Univ., NY (United States); USDOE
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; thermal spray; high velocity oxy-fuel; fatigue; residual stress; WC-CoCr
OSTI Identifier:
1345538
Alternate Identifier(s):
OSTI ID: 1361652