Zuihitsu on Phase Diagrams

Rangu
1. The first phase diagram to be established was that of Iron-Cementite. It has an Indian connection. The wootz steel of Karnataka had challenged the best brains of England, France, Sweden and Russia to replicate it. A Swedish chemist showed that it is not a metal but an alloy of Fe and C. It was left to Roberts–Austen at Cambridge to study the phase relationship of Fe-C. He became immortalized as the fcc variant of C in solid solution in Fe was named Austenite. It was Roozeboom who drew the contours of the Fe-Fe3C diagram in the year 1900. The new century saw Neville & Heycock again in Cambridge establish the Cu-Sn phase diagram. Though Bronze and Iron have been mastered by mankind without the benefit of detailed knowledge it is interesting that two studies at Cambridge gave insights into these materials.
Footnote on Roozeboom from the web
“One of Roozeboom’s major contributions to science stemmed from his appreciation of the work of Josiah Williard Gibbs and of his taking Gibbs’ work which was regarded as algebra and incomprehensible and preach the gospel to the heathens. Roozeboom was assistant at the University of Leyden, and eventually moved to Amsterdam to occupy van’t Hoff’s chair when the latter went to Berlin. Most scientists and engineers are familiar with what is today known as the Gibbs phase rule, first published by Gibbs in a 321 page paper as “On the Equilibrium of Heterogeneous Substances “. Van der Waals, professor of theoretical physics at Amsterdam, was familiar with the work of Gibbs and delivered a lecture in 1886 which included a thermodynamic interpretation of Roozeboom’s data on the hydrobromic acid-water system. This lecture was a revelation to Roozeboom and ignited his interest in the phase rule. He immediately started to study Gibbs’ paper. The phase rule had been published eight years before and had been complelety ignored by chemists and never systematically applied by anybody.Volume I of Roozeboom’s work The Heterogeneous Equilibria from the Standpoint of the Phase Rule was claimed by Ostwald in 1905 as one of the few books that required no explanation for its appearance, it being an indispensable part of every physicochemical library . Klooster tells us that “Roozeboom’s untimely death at the age of 52 deprived him of the recognition and honors which would have been given him for his incomparable achievements. Deeply religious and sharing the aversion of common people to speculative philosophy, he looked upon the phase rule as an expression of divine intent to regulate the material world”.
2. The famous Aranmulla Mirror of Kerala is now known as one of first intermetallic compound to have found utilitarian and aesthetic value
2. 1900 was followed by feverish activity of determining phase diagrams –in particular the binary alloys. England and Germany (notably Tammann at Goettingen) spring to mind. In addition to the determination of phase diagrams Hume-Rothery at Oxford was able to rationalize the observed structures. K Schubert was totally immersed and had several Indian colleagues , notably Aravamudan Raman and Suraj Bhan The Russian Schools have contributed enormously as well.
3. A century later we have 4,700 phase diagrams for 3,300 binary metal systems and7,380 ternary phase diagrams for 3,300 alloy systems. This activity is continuing. T B Massalski became a driving force. The Alloy Phase Diagrams International Commission plays a nodal role. The establishment of The Linus Pauling File as a repository is an impoortant development with Japan playing a leading role
4. Dara Antia put India on the map. He nurtured the talents of Prof V Raghavan who has evaluated more Fe diagrams than any one else. The first ever monograph on Quaternary alloys had an Indian author-V Raghavan. The accomplishment can be savoured as this is the only monograph on a quaternary system. We have nearly 50 on Binary alloys and 30 on ternary alloys Among the former is one by Rama Rao and Naidu on Tungsten Binary Phase Diagrams and another by R Krishnan on Tantalum.
5. The expansion into ternary and multinary alloys poses enormous challenges
6. Our mind goes to 1973 in Varanasi, when Prof T R Anantharaman delivered the N P Gandhi Memorial Lecture on Transformations – Metallurgical and Mental. It tries to draw parallels between two disparate things using phase diagrams and was met by rapture and scepticism.
An aside on Henry Adams from the web
“There is an anticipation of this lecture by Henry Adams. The Rule of Phase Applied to History” in Degradation attempts to find an analogy in the physical sciences for Adams disintegration theory of history. For his purpose he found Willard Gibbs’s work on the “Coexistent Phases of Matter” to be useful. For example, ice, water, and water-vapor are three phases of a single substance under different conditions of temperature and pressure. The phases are compared with stages in human history. “As science touches every material or immaterial substance, each in its turn dissolves, until the ether itself becomes an ocean of discontinuous particles …. If every solid is soluble into a liquid, and every liquid into a gas, and every gas into corpuscles which vanish in an ocean of ether, -if nothing remains of energy itself except potential motion in absolute space,–where can science stop in the application of this fecund idea?” (Degradation 269-70). In his letters, Adams complains that science does stop too soon; he takes up where science leaves off and applies this theory of acceleration toward entropy, the state of disorganization and non-availability of energy described by the second law of thermodynamics, to human history. Pressure in physics represents “Attraction,” the historical rule of phase which gives to history its forward movement. Temperature represents Acceleration; Volume, mares Thought. Positing the mechanical age, 1600-1900, as the one of which he is most sure, by the law of inverse squares Adams concludes that social energy is in an ever-accelerating state of disintegration and leveling out, not in fine gradations but in jumps, and that human thought should reach its limits in 1921. The inadequacy of this theory was obvious even to Adams, and critics still disagree concerning Adams’s attitude toward his own theory, but as the theory itself stands, it strongly confirms Adams as a secular “prophet of doom.”

September 10, 2003

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