A galling failure model: Development of predictive framework for iron based hardfacings based on crystal plasticity finite element
File(s)
Author(s)
Barzdajn, Bartosz
Type
Thesis
Abstract
An investigation of rough metal to metal contacting surfaces under normal load and undergoing sliding has been carried out with explicit representation of measured surface profiles within a crystal plasticity finite element formulation in which grain size, texture and slip properties are incorporated. A new metric called plastic reach has been introduced for contacting surfaces which reflects both the magnitude of the local surface asperity plasticity and its spatial reach. This quantity has been shown to obey a power law relationship with the applied normal load for sliding contact which in turn has been related to a hazard function. In this way, a new methodology to predict the galling frequency that follows a Weibull distribution has been established. Additionally, a quantitative definition of galling for the class of metal on metal contacting surfaces is considered. The predicted galling frequency distribution for a 316 stainless steel has been compared with independently experimentally measured galling frequencies showing good agreement. An assessment of confidence limits has also been provided for the modelling methodology, followed by sensitivity studies. The latter resulted in first recommendations for our industrial partner, on how to improve galling resistance of hardfacing alloys.
Version
Open Access
Date Issued
2018-08
Date Awarded
2019-04
Copyright Statement
Creative Commons Attribution NonCommercial NoDerivatives Licence
Advisor
Dunne, Fionn
Sponsor
Rolls-Royce plc
Department of Materials, Imperial College London
Publisher Department
Materials
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)