Emerald Group Publishing Limited
Copyright © 2002, MCB UP Limited
In this issue we have three technical papers. Colleagues from two Brazilian and one British University present a very interesting piece of work concerned with the measurement of the chip-tool interface temperature in a metal machining operation.
Many researchers have looked at different methods for assessing this temperature but most methods also suffer from potential problems as highlighted in the paper. The paper proposes a different method, which is likely to be of use to other workers. Of course at present much work is being done to enable dry or minimum fluid quantity cutting conditions to be established. This paper would seem to help to establish how an important parameter in the machining process can be established.
Workers at Tsinghua University in Beijing, China and at General Motors Corporation in USA have been examining the tribological reaction when a lubricated piston ring/ cylinder bore system is subjected to stepped heating conditions. The lubricant used was a good quality engine oil with and without a 3% treatment of molybdenum dialkyldithiocarbamate. Plots of friction against temperate show some very interesting results and the compounds formed show the complexities caused by the friction modifier. It will be interesting to see in future if further work in this area can look at repeating the work in a motored engine to see if similar friction characteristics are obtained.
Our third paper is by Walter Holweger of the University of Tubingen in Germany. This work is linked to his previous published papers and is taking a very different look at "Lubricated for life" systems. He has studied the chemical reactions resulting from lubrication and how these vary from the metal surface into the body of the component. Especially if water is present then it is argued that a 'chemical pathway' can be formed which will actually promote surface failure. It is possible that some lubricates may be capable of preserving unwanted and potentially damaging chemical compounds from the tribo-chemical reaction within their own matrices. Some very challenging and thought provoking ideas are captured in this paper.
In this issue we also include some items of general interest to lubricant users. Mike Ward, of Mike Ward Associates, sets out the situation in Europe regarding legal changes affecting the disposal of used lubricants previously burnt as fuel oil. In addition NSK provide some useful background information on bearings.
We hope your enjoy this issue and look we look forward to publishing your work at some time in the future.