THE ROLE OF CHEMISTRY IN MODERN METALLURGICAL ENGINEERING' ARTHUR A. BURR Rensselaer Polytechnic Institute, Troy, New York
INDISCUSSING the role that chemistry plays in any engineering field, the non-chemist is faced with a definition of terms. On consulting the basic textbooks in the field he finds: "Chemistry may be defined as the science which treats of the composition of matter and the changes in composition and energy which matter undergoes." One author goes so far as to state that previous to 150 years ago there was no science of chemistry. Admittedly, a curiosity about the composition of matter and, incidentally, of metals existed a t a much earlier date. Traditionally it seems to have been the chemist who has pioneered knowledge about matter and its behavior, and since metals are matters of interest t o chemists along with other things, one can begin to see an early correlation between the two subjrat.. On the other hand, cvcn to the sciel~tistir is obvioui that in the field of enainerrine. where tvnditionallv the objective has been to'pply h%ic knowledge to aewide range of indwtrial processes and problems, the store of facts and figures has become so great that specialization or, essentially, segregation of the various areas of this knowledge, has become necessary and has been going on over the years. This has given rise to several branches of so-called pure science and to more branches of engineering. Even the somewhat definitive title metallurgical engineering" has many implications. To those who are concerned with development of future curriculums the field sometimes looks like a manytentacled octopus. Subdivisions include physical metallurgy, process metallurgy, mineral dressing, mechanical metallurgy, metal processing, foundry metallurgy, corrosion of metals, solid state physics, high temperature metallurgy, welding metallurgy, powder metallurgy, nuclear metallurgy, and so on. However, heyond elementary mathematics, physics, and chemistry, the field of metallurgy may be characterized by four principal scientific themes? (1) thermodynamics, (2) structure of matter, (3) engineering mechanics and behavior of materials, (4) rate processes. I n addition, specialized techniques have been developed over the years for the stud;.- and control of composition, strutI(
' Presented at the Nineteenth Annual Summer Conference of the New England Association of Chemistry Teachers, Colby College, Waterville, Maine, August 20, 1957. f h n m M . 4 ~ ~R., , JR. Paper presented before the Mineral Industry Education Division of the American Institute of Mining and Metallurgical Engineers, February, 1954.
ture, and shape of the substances of metallurgical interest. From this description one can readily see that chemistry will play an important role in building an educational foundation for metallurgical engineering. With the exception of item (3) above, most chemical curriculums would include items (I), (Z),and (4). In developing the subject further, it is convenient to discuss two aspects of the role of chemistry: first. in college curriculums, and, second, in the industrial practice of metallurgical engineering. Current practice is presented and is followed by some of the problems that must be faced to meet future trends. Smce the author is concerned mainly with educational practices, most emphasis is placed on this as~ect. CHEMISTRY IN CURRICULUMS FOR METALLURGICAL ENGINEER,NO
I n recent years considerable attention has been devoted to the content of engineering curriculums in general. A report on "Evaluation of Engineering Education (1952-55)," by the American Society for Engineering Education, outlines a time distribution for scientifically oriented engineering curriculums. A glance at present and future problems in the field indicates that metallurgical engineering has no choice but to become scientifically oriented. A summary table from the report is reproduced in Table 1. TABLE 1 Summary of Time Distribution for Scientifically Oriented Curriculums Subject mntter Humanistic and social studies Mathematics and basic sciences (about equal weight) 3. Engineering sciences (e.g., applied thermodynamics, etc.) 4. Seauence of eneineerine - subiects . fi.e.. , , fbr major fieid) 5. Options or electives 1. 2.
'sf
currzculurn About one fifth .4bout one fourth About one fourth .4baut one fourth About one tenth
'
It will be noted that chemistry would fall in item two which consists of mathematics, physics, and chemistry in equal proportions. This would mean a minimum time allotment of about 8% of the curriculum content for chemistry. Another point of interest is the recom-
100
JOURNAL OF CHEMICAL EDUCATION
mendations of the report with regard to chemistry. These are quoted below: .. .chemistry should include topics in inorganic, organic and physical branches presented in condensed and generd form. The initial study must prepare engineers to enter sdvsnced courses in chemistry and in its application to such fields 6s properties of materials, metdurgy, fuels and combustion, corrosion and industrial chemicd processes. Hence, suoh subjects as rate8 and kinetics of chemical change, chemical equilibria, phase diagrams, solutions, electrochemistry, and colloids should he included. Careful coordination should d.30 be effected between modern physics and chemistry. For studies beyond the usual freshman chemistry course it is felt that physical chemistry deserves the main emphasis.
Even t,he most ambitious chemistry teacher will admit that these recommendations would require very careful use of allotted time. It will also be of interest to look at an approximate time scale for some typical metallurgical engineering curriculums. Table 2 shows this for five major colleges chosen more or less at random. The heading "other fields" in this summary refers for the most part to selected courses from other engineering fields such as mechanical, electrical, chemical engineering, and geology. The figures refer t o curriculums in use about two years ago. TABLE 2 % S~i~b'eet nzalter Sehool
School R
dhool C
School
School C
17 17 15
15 22 8 7
10 18 15
14
14
15 23 12 9 10 95
As
Geom.-mathmechanics Humanities Chemistry Physics Other fields Total Shop, R.O.T.C., P.T., etc.
lo 13 96
4
91
10 7 91
D
14 7 11 92
4 9 9 8 5 *If R.O.T.C., humanities, and other fields are dropped each about 2%.
School B had dropped some basic chemistry in favor of more in-department applied mork. Otherwise a reasonably uniform time allotment t o chemistry is noted. Taking the average engineering bachelor's degree as consisting of approximately 145 semester hours, approximately 20 semester hours are spent on chemistry on the average. In considering the use that is made of this time by the student, the R.P.I. curriculum is typical. Ten semester hours are spent on general chemistry, four on analytical and eight on physical chemistry. Sequential demands result in a distribution of these courses through the junior year. This sequence does not, however, complete the role that chemistry plays in metallurgical curriculums. Courses such as production metallurgy appear which is largely the chemistry of metal prodnction and metallurgical thermodynamics and electrometallurgy, which are obviously a version of applied chemistry. There are also basic physical metallurgy courses in which such topics as mechanics of solidification, phase transformations, and phase diagrams of metal systems are found. These subjects might be considered suitable fare for any physical chemist. VOLUME 35, NO. 2, FEBRUARY, 1958
Many curriculums also contain courses in ore benefication and metal refining among the major field offerings. In summary it might be said that metallurgical engineering depends heavily on the integration of chemistry as a pure science of materials into an engineering field centering mostly around problems resulting from the use of metals. If one were to walk through the laboratory facilities of the average department of metallurgical engineering, the role of chemistry would also be noted here. For example, at R.P.I. you would find a spectrographic laboratory, a gas analysis laboratory complete with mass spectrograph, an X-ray diffraction laboratory, and numerous laboratory benches characterized by stone tops, water, gas and air supplies, and rows of reagent bottles along the shelves. Even in the staffs of the metallurgical departments, chemistry has its role. Among a staff of ten at R.P.I., one member is a Ph.D. chemist and four were graduated in chemical engineering and did their graduate work in metallurgy. Education in modern metallurgical engineering faces numerous problems, many of which concern the role of chemistry. One definite problem is time. The impact of nuclear and other modern technological developments has greatly increased the amount of suhject matter t o he considered. This in turn will force more specialization or some rearrangement of time in the curriculums and will bring the whole subject mat ter under scrutiny, chemistry included. Another problem is that of overlapping. At the foundation level overlapping occurs between physics and chemistry. I n the departmental courses perhaps too much effort is being wasted in re-teaching, at the applied level, material which has already been covered but not correlated. A third problem is one of liaison between basic and applied fields. Inadvertently in the trend toward specialization and the application emphasis of engineering we are building invisible walls in the minds of the students and perhaps even in the minds of the professors. This wreaks havoc with the scientific perspective of the average four-year graduate and generally means that he will spend another three or four years in graduate school or research heforeheregains perspective. I t is a moot question whether this lack of integration between foundation courses and applied courses is necessary. This problem for example has given rise to textbooks entitled, "Chemistry of Metals," "Structural Metallurgy," etc., to reemphasize basic prineiples. Although this approach has its value, one seriously doubts whether this is a satisfying way to introduce metallurgists to chemistry or chemists to metallurgy. For the past two years a study committee sponsored by the Department of Metallurgical Engineering at R.P.I. has been concerned with some of these problems. The group consists of both academic and industrial scientists and engineers. This is only one of several such studies. One of the outcomes of these deliberations has bw111111 :irt(:n~ptto dr.;ign :I eurrimlum nhivh makes morr efficient use of time. i i morr libeml in itgeneral content, and provides for the student an integrated perspective of his major field. A chart of these tentative effortsis shown in Table 3.
I n considering the role of chemistry iu this curriculum, it will he noted that the actual share of time devoted to chemistry as such has been decreased from 15% to slightly over 11%. This is done for two rather basic reasons: One is the fact that chemistry is a foundation course and the student should therefore have essentially completed his foundation before beginning to build up his major field interest; second, it appears that time can he saved for the engineer by cutting down on some laboratory experiences. I t seems of doubtful value, for example, that he become an expert in either titration methods or the use of the analytical balance. This change is not intended to minimize the role of chemistry in building the proper perspective. Having had a survey course in his major field simultaneously with the last semester of his science foundation, the student is scheduled for an extra six semester hours of applied chemistry including thermodynamics. These courses may he sought in the major department or from the department of chemistry depending on the availability of personnel with adequate background. This brings the over-all role of chemistry to about what -- ---
it was 011 a quantitative scale before. It is also hoped that hy proper integration the efficiency of the use of time in the chemistry department can be improved. The basic science departments at R.P.I. already have a study project underway in this area. I t will also be noted that additional time is available in this curriculum in an allotment of time to a minor field in which chemistry could also play a role for the scientifically oriented engineer. In the major field the perspective has been changed from one dominated essentially by development of various phases of technical detail to a sequence of basic principles fundameutal in the development and use of metals and alloys. The first courses, as already pointed out, are an extrapolation from the foundation courses. Considerable emphasis is placed on integrated laboratory work, and details of applied work are reserved until the senior year. Considerable assistance toward the success of such an approach mill come generally from the basic science teachers, both in supplying the student perspective and in assisting him to develop by ample use of inductive teaching techniques.
-
TABLE 3 Proposed Curriculum for Metallurgical Engineering at Renselaer Polytechnic Institute
102
JOURNAL OF CHEMICAL EDUCATION
CHEMISTRY IN INDUSTRIAL METALLURGICAL ENGINEERING
To turn now briefly to a consideration of the role of chemistry in industrial metallurgical engineering, it may be noted that the contribution here is also extensive. The areas in which it has been effective are a matter of record. A partial and by no means complete list of these is shown in Table 4. TABLE 4 Role of Chemistry i n Industrial Practice of Metallurgical Engineering 1. 2. 3. 4. 5. 6. 7.
8. 9. 10. 11. 12. 13.
Winning of metals from ores Calculation of furnace charges Refining and purifying metals Deoaidation, desulfurization,etc., of molten metals Chemical analysis of alloys Electroplsting and electrowinning Etching reagents and etching practice Surface cleaning of metal parts Control of furnace atmospheres Gas-metal processes, e.g., nitriding, cyaniding Solution chemistry (extrapolated to solid solutions) Thermodynamic studie~ Reaction kinetics
Industrial practice of today is also. showing an impact on the future trends of both academic practice and industrial needs. This is illustrated in the chart shown below, showing the areas where such needs are focusing attention. Methods of material study, selection, and improvement formerly used by the metallurgist are already being used to a considerable degree in the engineering
VOLUME 35. NO. 2, FEBRUARY, 1958
~
~
/ ~ Ceramics and ceremets (physical hchemists' ~ i nightmare) ~ ~
d use/ ~
'~emiconductors
\
(chemical purity)
'Polymers
development of plastics, ceramics, and semiconductors. I n view of the many similarities between the basic principles of behavior of these materials, it may well be that future trends will replace the metallurgical engineer with a new breed called something like a materials engineer. Such a development will certainly expand and increase the role of chemistry in this field. I n conclusion, it may be well to emphasize three major points: (1) Chemistry is the major foundation science for metallurgical engineering, and special aspects of chemistry make up an important part of the major field study. (2) A new look is needed at the problems of inteeration and wersuective in the role that chemistrv plays. This could very well start at t.he high school level. (3) The impact of modern technological and industrial development has made this field a bottleneck area. Present trends are changing the emphasis and making it mandatory that better use be made of its foundation in science. The chemistry teachers will play an important part in these developments.
