The Present Status of Metallography

Abstract

The metallographer has a prime responsibility as a member of a metallurgical or, in many laboratories, a materials team. In addition to his duties of specimen preparation and assistance in interpretation of microstructures, he must keep abreast of new techniques and developments or develop his own as they are needed. The Space Age and particularly the problems of the Nuclear Age have climaxed the obstacles of this field. The daily remote handling of highly radioactive or toxic materials or both, which only a few years ago were textbook curiosities, has removed the “touch” formerly considered an essential part of the operation. Almost all the preparation and investigational steps performed in a conventional laboratory can be carried out by remote operations. New techniques in revealing the microstructure in color by staining and anodizing are becoming very popular. Although the colors usually produced have enhanced the art tremendously, the benefit is not confined to beauty. Reaction mechanisms such as corrosion and diffusion as well as variations in crystallographic orientation have been understood more clearly from color interference patterns or basic color changes. This information can be recorded in the laboratory by adopting the present techniques in color photography. The development of commercial equipment allied to the objectives of the metallographer has been a big help. The microprobe analyzer permits essential analyses of microscopic areas. Hot stage microscopy equipment allows us to view grain boundary movements and other features formerly confined to the imagination. Quantitative data are obtainable now in a fraction of time formerly required. Along with this development of commercial equipment, there have been “inlab” modifications which show great promise. Many challenges remain and new ones can be seen in the near future. One in particular is the uncertainty of availability of well trained or professional metallographers. Current trends in metallurgy and materials science curricula seem to be decreasing the amount of metallographic training. If this trend continues, there will be an even greater requirement for “professional metallographers.”

Proceedings of the fourth international congress for stereology

“…Honors included: Phi Beta Kappa, Sigma Xi, Alpha Omega Alpha, the Capp Prize and the Banting medal of the American Diabetes Association. A member of 23 scientific societies, Arnold was elected to office in many of them; he was secretary of the International Society for Stereology from 1968 Lazarow died June 25,1975 after a brief illness.…”

“…Since the mean perimeter of the projection of a convex set onto an isotropic random plane is ttW , we have (25) pl^= tn TT M . whether, for the relevant point on a ± arc, it is within or without the projection of the associated portion (each case has probability %) ; and…”

“…Partial correlation coefficients for the overall n-dimensional systems are shown in the upper triangle of this table. Of the 45 correlation coefficients for which full observations are available in Data C, 25 are statistically significant at the 95% confidence level (*) . The matching partial correlation coefficients show reversed sign in 13 cases, of which 6 are above the 95% confidence level for 1 or both coefficients.…”

“…Also, it should be noted that standard deviations for the point counts on vessels of the four diffuse-porous woods appear to be independent of species, whereas sassafras, which is ring-porous, shows an appreciably larger variation in vessel area fraction across its growth rings. 11) 7( 5) 55( 14) R--3 .2(1.1) 17( 6) W 10 ( 6) 27( 14) 8( 6) 45( 14) T--3 .9(1.5) Total 37 (25) 48( 23)15 (9) 100( 14)…”

Metallographic examinations of retrieved intramedullary bone pins and bone screws from the human body

“…Metallography is a major tool of the materials scientist in postservi evaluation of component failures [3]. The metallographer is an essentj team member, contributing to materials development in much the sar way a pathologist contributes to analyses and advancements in t medical profession.…”