The Physics and Chemistry of Solids (PCS) Group (now Surfaces, Microstructure, and Fracture (SMF)) was founded by the late Prof. Philip Bowden. He was of Tasmanian origin and had come to Cambridge in 1927 to do a PhD in electrochemistry. When he founded it in 1945, the group was known as the Physics and Chemistry of Rubbing Solids (PCRS) and was part of the then Department of Physical Chemistry. In 1957 Philip Bowden was made a Reader in Physics and his laboratory became a sub-department of the Cavendish Laboratory. Its name was changed at the same time to PCS. In 1966 Philip Bowden was given a personal chair in Surface Physics. So for a time the lab was known as the Surface Physics section of the Cavendish. Philip Bowden died in 1968. His obituary was published in the Biographical Memoirs of Fellows of the Royal Society. A full list of his publications is also available.
A link to an article published to commemorate the centenary of Philip Bowden's birth and reviewing his contribution to the Australian war effort may be found by clicking on:
"An antipodean laboratory of remarkable distinction" by N.N. Greenwood & J.A. Spink, Notes and Records of the Royal Society of London 57 (2003) 85-105 The second head of the laboratory was David Tabor. He died in 2005. His obituary was published in the Biographical Memoirs of Fellows of the Royal Society. A full list of his publications is also available as is an article outlining his contributions to the study of hardness and indentation.
Philip Bowden. Founder and Head of PCS 1945-1968
David Tabor. Head of PCS 1968-1981
Abe Yoffe Head of PCS 1981-1987
The present research interests of the group can be traced to work Philip Bowden started in the 1930s on a range of friction problems (as a result of the influence of Sir W.B. Hardy) including:
- Frictional hotspots generated when dissimilar metals are slid over each other (being dissimilar they form a thermocouple junction allowing the temperature to be measured)
- The Beilby polishing layer.
- The range of surface forces.
- Friction of ice and snow (Bowden was a keen skier).
- In situ velocity measurement.
- Stick-slip motion.
This early work was published in a series of classic and seminal papers:
1931 Bastow, S.H. and Bowden, F.P. "On the contact of smooth surfaces", Proc. R. Soc. Lond. A134 404-413 1935 Beare, W.G. and Bowden, F.P. "Physical properties of surfaces. I: Kinetic friction", Phil. Trans. R. Soc. Lond. A234 329-354 1935 Bastow, S.H. and Bowden, F.P. "Physical properties of surfaces. II: Viscous flow of liquid films. The range of action of surface forces", Proc. R. Soc. Lond. A151 220-233
1935 Bowden, F.P. and Ridler, K.E.W. "A note on the surface temperature of sliding metals", Proc. Camb. Philos. Soc. 31 431-432 1936 Bowden, F.P. and Ridler, K.E.W. "Physical properties of surfaces. III: The surface temperature of sliding metals. The temperature of lubricated surfaces", Proc. R. Soc. Lond. A154 640-656 1936 Bowden, F.P. and Hughes, T.P. "Physical properties of surfaces. IV: Polishing, surface flow and the formation of the Beilby layer", Proc. R. Soc. Lond. A160 575-587
1936 Bowden, F.P. "The temperature of lubricated surfaces", Proc. R. Soc. Lond. A154 640 1938 Bowden, F.P. and Hughes, T.P. "Friction of clean metals and the influence of surface films", Nature 142 1039
1938 Bowden, F.P. and Leben, L. "The nature of sliding and the analysis of friction", Nature141 691 1939 Bowden, F.P. and Hughes, T.P. "The friction of clean metals and the influence of adsorbed gases. The temperature coefficient of friction", Proc. R. Soc. Lond. A172 263-279 1939 Bowden, F.P. and Hughes, T.P. "The mechanism of sliding on ice and snow", Proc. R. Soc. Lond. A172 280-298 1939 Bowden, F.P. and Leben, L. "The nature of sliding and the analysis of friction", Proc R. Soc. Lond. A169 371-391 1939 Bowden, F.P. and Tabor, D. "The area of contact between stationary and between moving surfaces", Proc. R. Soc. Lond. A169 391-413 1940 Bowden, F.P. and Leben, L. "The friction of lubricated metals", Phil. Trans. R. Soc. Lond. A239 1 1942 Bowden, F.P. and Tabor, D. (1942) "The mechanism of metallic friction", Nature150 197 1943 Bowden, F.P., Moore, A.J.W. and Tabor, D. "The ploughing and adhesion of sliding metals", J. Appl. Phys. 14 90-91 1943 Bowden, F.P. and Tabor, D. "The lubrication by thin metallic films and the action of bearing metals", J. Appl. Phys. 14 141-151
1944 Bowden, F.P. "The physics of rubbing surfaces", J. Proc. R. Soc. New South Wales78 187-195 1947 Bowden, F.P. and Young, J.E. "The friction and adhesion of clean metals", Nature164 1089
In the summer of 1939 he went on a lecture tour of America and combined it with a trip to Australia to meet old friends and family. Almost immediately World War II broke out and he offered his services to the Australian Government to set up a group to help the Australian war effort, particularly on problems of friction, lubrication, bearings and wear. The lab co-operated with a bearing manufacturer in producing effective bearings for the newly developing aircraft industry in Australia.
In 1941, he was introduced to another topic that was later to play an important part in PCS after the war. The Australian munitions industry was concerned about an unexplained detonation of a vat of nitroglycerine at the ICI factory at Deer Park near Melbourne causing serious damage to the factory and precincts. Nitroglycerine was used for the preparation of dynamite and blasting gelatine. The work was begun by Wilson, who had been seconded to Bowden's laboratory. His other duties included checking lubricant viscosities and electroplating cylinders from Pratt & Whitney aircraft engines. A.D. (Abe) Yoffe joined in late 1941 to take over Wilson's work when he left at the end of 1941. The experiments of ADY (together with Maurice Mulcahy and Bob Vines, who joined in 1942) led to the discovery of the very large sensitizing effect of the presence of tiny gas bubbles in nitroglycerine. This is well documented in the book "Initiation and Growth of Explosion in Liquids and Solids" by F.P. Bowden & A.D. Yoffe, published by Cambridge University Press in 1952 as well as in the recent paper by Greenwood and Spink for Notes and Records of the Royal Society. Later, work by Stone and Tudor on the possible initiation of explosion by friction, taken together with the other work, led to the concept of 'hot spots' as the necessary condition for explosion to occur (see, for example, Bowden, F.P., Stone, M.A. and Tudor, G.K. "Hot spots on rubbing surfaces and the detonation of explosives by friction", Proc. R. Soc. Lond. A188 (1947) 329-349). The probable explanation for the Deer Park disaster was that it was due to the 'water hammer effect', again caused by adiabatic compression of gas inclusions in the piping from the vat.
In studying how fast-moving particles could produce detonation, a couple of Bowden’s engineer graduates developed an electronic device for measuring the velocity of the particles by determining the time of flight between two points in the flight path. The idea of using electronics to measure short-time intervals was very new. In due course this led Courtney-Pratt to develop portable equipment which could be placed on the decks of battle-ships and used to measure the muzzle velocity of naval guns in situ on the ship itself. He calibrated the guns of the Australian Navy and was dispatched to England to do the same for the British Navy.
At the end of the war, Philip Bowden returned to Cambridge and became a lecturer in the Physical Chemistry Department. He brought with him some of his more experienced scientists from Australia, including David Tabor, Abe Yoffe, Jeof Courtney-Pratt, and Alan Moore. They were soon joined by some graduates from Cambridge and other universities. The programme was very much a continuation and development of work in Melbourne, and it is significant that Bowden called it the Physics and Chemistry of Rubbing Solids. The main areas of work were initially friction, lubrication, and chemical decomposition produced by friction and analogous processes. These studies gradually developed to include the erosion of solids by liquid impact, the strength and fracture of solids, the effect of molecular structure on the chemical stability of explosives, and the relation between structure and the optical and electronic properties of solids.
Within five years or so the laboratory was beginning to develop its own character. Alan Moore was developing taper sections; Brent Greenhill was studying EP lubrication with chlorine and sulphur-based additives; Eric Tingle was looking at the protection offered by oxide films; Ernst Rabinowicz introduced radioactive tracers to study adhesion and transfer; Jim Menter started the use of the earlier type of electron diffraction equipment to study surface films, and later modified an existing electron microscope in reflexion to product the first direct observation of dislocations; Anita Bailey and Jeof Courtney-Pratt introduced mica as a model surface; Peter Gray demonstrated the rôle of the vapour phase in the detonation of liquid explosives; Abe Yoffe extended his study of explosive reactions to the structure of azides and later to the electronic properties of layered solids. In the background there was increasing use of Jeof Courtney-Pratt’s cameras to study high-speed phenomena in detonation and in mechanical erosion.
In the early 1950s, Nevill Mott was appointed Cavendish Professor. Nevill Mott was the father of solid state physics in the UK. Although a theoretician, he had close contacts with industry and had been involved in many wartime activities. He not only solved the problem of how photographic processes occur, he worked on dislocations and wrote a seminal paper on indentation hardness. He understood Philip Bowden’s interests and approach. They were also both Fellows of Gonville & Caius College. As a result of discussions between them, Philip Bowden resigned from Physical Chemistry and was taken on by the Cavendish. Nevill Mott gave strong support to the lab and encouraged its involvement in the study of the electronic properties of layered materials.
Bowden’s lab was the first University group that was interdisciplinary in its research (long before that word was invented). This initially gave rise to some problems, particularly in relation to teaching, supervisions, and examining; but these were gradually resolved. However, there were few difficulties about research funding because of Bowden’s wise choice of research themes and because of the confidence that Industry had in his projects. One might in fact describe Philip Bowden as a scientific entrepreneur. He was indeed extraordinarily successful in winning the support of Industry and Government departments.
Books published by PCS staff members as a result of work performed up to 1968:
The Friction and Lubrication of Solids. Part I. F.P. Bowden & D. Tabor, Clarendon Press, Oxford, 1950. 2nd edition 1954. Reissued as an Oxford Science Classic in 1986 and printed again in 1996.
The Friction and Lubrication of Solids. Part II. F.P. Bowden & D. Tabor, Clarendon Press, Oxford, 1964.
The Hardness of Metals. D. Tabor. Clarendon Press, Oxford, 1951. Reissued as an Oxford Science Classic in 2000.
Initiation and Growth of Explosion in Liquids and Solids. F.P. Bowden & A.D. Yoffe. Cambridge University Press, 1952. Reissued as a Cambridge Science Classic in 1985.
Friction and Lubrication. F.P. Bowden & D. Tabor. Methuen, London, 1956. Revised and enlarged edition published in 1967.
Fast Reactions in Solids. F.P. Bowden & A.D. Yoffe. Butterworths, London, 1958.
Friction in Textiles. H.G. Howell, K.W. Mieszkis & D. Tabor. Butterworths, London, 1959.
Radiation Damage in Crystals. L.T. Chadderton. Methuen, London, 1965.
Gases, Liquids and Solids. D. Tabor. Penguin Books, 1968. A second edition was later published by Cambridge University Press in 1979. It is now in its third edition and is widely regarded as a standard undergraduate text on the properties of matter.
Electronic Processes in Non-Crystalline Materials. N.F. Mott & E.A. Davis. Clarendon Press, Oxford, 1971.