We are jointly organising an event in London on 19 July 2017 on Chemical Challenges in Tribology. Full details including how to register are given here.
Here is the final programme for the event:
10:00 to 10:30 am Registration with tea / coffee
10:30 to 10:40am Welcome
10:40 to 11:20am Ian Hutchings
11:20 to 11:50am Robert Wood
11:50 to 12:20pm Hugh Spikes
12:20 to 12:50pm Anne Neville
12:50 to 2:10pm Lunch and posters
2:10 to 2:40pm Chris Warrens
2:40 to 3:10pm Nichole Dorr
3:10 to 4:30pm Tea and open discussion / networking
The following abstracts have been received so far:
Soot Aggravated Wear
One of the concerns for vehicle manufacturers looking to increase oil drain intervals in their engines is the impact of wear on engine durability caused by soot dispersed in the oil. Whilst this has historically been of concern in diesel engines, the introduction of down-sized boosted direct injection gasoline engines means that this is also potentially important in gasoline engines as well. The lterature on soot aggravated wear describes a number of potential wear mechanisms. This study aims to identify the principal wear mechanisms and to deconvolute the roles of soot build up and lubricant anti-wear degradation on the lubricating properties of used engine oil.
Challenges of studying at the interface between tribology and electrochemistry – A tribocorrosion story
RJK Wood, Professor of Surface Engineering and Tribology, The National Centre for Advanced Tribology at Southampton (nCATS), Associate Dean for Research, Faculty of Engineering and the Environment, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
We are experiencing a large growth in the use of mechanical systems that have to survive and operate in increasingly harsh corrosive environments. This growth is being driven by a switch to offshore renewables, marine resource recovery (such as deep-sea mining, oil and gas), aquiculture, shipping, and legislation and low environmental impact drivers and so on. Therefore, this talk will look at the challenges of studying tribological interfaces in corrosive environments. This can involve the coupling of electrochemical techniques developed to study very well characterised and controlled solid/liquid interfaces into a mechanical testing environment with engineering materials and environments. This results in unavoidable tensions when analysing electrochemical output from such tribocorrosion tests. Recent research into the performance of cast nickel aluminium bronze, cemented and thermally sprayed tungsten carbide under various tribocorrosion conditions will be used to illustrate certain challenges (for example the quantification of interactions between mechanical and electrochemical processes). The gravimetric, surface profilometry and in situ / ex-situ electrochemical measurements will be discussed and mechanisms illustrated by microstructural analysis. The influence of surface films will be explored with regard to the temporal aspects of film removal and repair along with complimentary wear rates, friction and corrosion currents. Although the above studies use electrochemical techniques to monitor degradation of contacts some examples of where electrochemical techniques can be used to control friction and add functionality will be also be discussed.
Mechanochemistry in Tribology
In Tribology the conditions within rubbing contacts are often extremely severe and this is well known to promote chemical reactions of the lubricant; for example polymer degradation, antiwear and extreme pressure film formation and hydrogen emission via hydrocarbon cracking. The term “tribochemistry” is often applied as a catch-all descriptor of these in-contact reactions. Many mechanisms has been suggested as drivers for tribochemistry including flash temperature, ultrahigh pressure, emission of energetic particles such as electrons from rubbed surfaces, generation of active surface and even inversion of the Boltzmann energy distribution of surface atoms.
Recently attention has focussed on another driver of tribochemistry, that the mechanical forces applied to individual molecules in a contact promote reaction via stress-augmented thermal activation – essentially the stretching of chemical bonds so that less thermal energy is needed to break them. In classical chemistry this process is nowadays called mechanochemistry and this talk will explore the development of the concept of mechanochemistry in Tribology. It will describe recent work that shows unambiguously that at least one important tribochemical reaction, that of ZDDP tribofilm formation, is controlled by applied mechanical forces within the liquid phase and is thus a manifestation of mechanochemistry.