INSTITUTE FOR The Institute for Materials Research (IMR) is the principal focal point in the Federal Government for assuring maximum application of materials sciences to the advancement of technology in industry and commerce; it provides the main materials support to the other missions of the National Bureau of Standards. IMR assists and stimulates industry and commerce in the development of new and improved products and services by supplying an ever increasing understanding of the basic properties and improved characterizations of materials as well as by providing relevant measurement science and technology. The objectives of IMR are to: (1) develop techniques for the preparation and characterization of materials and for scientific studies on these materials, (2) identify and measure meaningful physical and chemical properties of materials under carefully controlled conditions, (3) supply on-site calibration services to science, industry, and commerce through a standard reference materials service, (4) provide technical assistance to other government agencies on request for advisory and problem solving, and enhance the national materials science capability as a part of administration policy, (5) identify critical materials problems preventing the attainment of major national goals and furnish unique relevant assistance, (6) insure maximum interchange among IMR and industry, commerce, science, and other government agencies through various means of technical data dissemination. Materials are the major problem and frequently the limiting factor in many major programs undertaken by both industry and Government to achieve national goals. High performance, utmost reliability, precise predictability and reproducibility of materials are necessary. Failure to meet or be able to measure these requirements in many instances, has led to widespread concern at the evident gaps in knowledge of production and identification of materials that exhibit adequate reproducibility for engi neering purposes. PREPARATION AND CHARACTERIZATION OF MATERIALS Preparation is the processing necessary to produce samples of materials with controlled chemical purity, composition, homogeneity, physical order, and required geometric shape. Characterization is the description of the composition and structure of a material that is significant for a particular operation and that suffices for reproduction of the material. Such descriptions have become indispensable in materials research, definition of standards, production of standard reference materials, and the acquisition of reference data. Preparation Pure Copper Prepared. The purest copper ever made has been prepared by IMR scientists. The large single crystals contain no impurities that can be detected by emission spectroscopy. In the course of this study, extensive cryostat and instrumentation facilities were developed to study copper and its dilute alloys. In addition, results of the study gave the first significant information on the electronic mean free path in copper. This work is a contribution to the understanding of basic properties of materials and will permit advanced engineering hitherto impossible. New Purification Technique.-A new purification technique has been developed which may permit the preparation of crystals approaching absolute purity. Experiment shows that the impurity content is reduced by a factor of as much as 10 in each half-hour stage of operation. A conjecture has been drawn that any number of stages can be employed with the same degree of purity improvement with no recontamination. This technique demonstrates a new idea and is a major advance in purification methods. It may lead to better processes in major crystal growth industries, spawn new industry and permit more sophisticated research in the universities. and research institutes. Characterization Significant developments have been made in this important area of activity. Many new and improved analytical procedures were developed during the year. Some of the more important ones are described below. Radiochemical Method Analyses Metal Chelates.-A new radiochemical method was developed for analyzing metal chelates. Chelates are widely used in analytical chemistry for separating metal compounds, and are useful as antidotes for poisoning by toxic metal compounds. For most uses, composition of the chelate must be accurately known. This method is more Close-up view of the NBS apparatus used to obtain ultrapure materials. One impurity in the substance is a red dye which shows as gray in the picture. Two silver strips (left center) are in front and back of a crystallizing mound. Note that the color of material in the mound is lighter than the surrounding liquid because it is rejecting the dye impurity as it crystallizes. direct and reliable than previously used optical methods and can be used in untidy environments-in oil sludge or blood, for example. Spectroscopic Technique Analyses High Temperature Alloys.-IMR scientists desired an improved spectroscopic technique for chemically analyz ing the high-temperature alloys being used in increasing quantities in modern technology. The technique is readily adaptable to existing instrumentation and can save industry time and money because the number of primary standards needed to calibrate the analytical equipment is reduced. Measurement of Tellurium in Metals.—A new method was developed for measuring small amounts of tellurium in metals. Small amounts of tellurium in metals provides advantages such as increased machinability of brass. The tellurium content of new standard reference brasses and cast irons is now certified, based on measurements using the new method. Analysis of Noble Metal Alloys.-X-ray emission analysis was adapted for precise and rapid analysis of noble metal alloys. The time required for a complete analysis is only one-tenth that required for conventional wet chemical methods. The procedure is applicable to the manufacture of previous metal alloys in their production and quality control. Also, dental research will benefit. For example, the American public can expect to save many thousands of dollars per year in dental care costs as a result of the cooperative research program of the American Dental Association at NBS. Solid NMR Studies.-The phenomenon of Nuclear Magnetic Resonance (NMR) was shown to be useful as an analytical technique in analyzing certain solid pieces of metal. In cases where the technique is useful, the costly procedure of first preparing a fine powder from the bulk material can be eliminated. Soft X-ray Spectroscopy. The usefulness of soft x-ray spectroscopy was increased by the removal of several inhibitors that had plagued the field for some time. Soft x-ray techniques provide information on the electronic structure of metals and alloys and, in general, open the way for obtaining better information on why materials behave as they do. Certain nickel alloys have already been studied and much useful data obtained. X-ray Spectrometric Analysis of Metal Alloys.-An x-ray spectrometer which performs rapid chemical analysis of a wide range of metallic alloys was developed. Devices in this family, often used for on-line production control, can be switched from analysis of one metal to another only with considerable difficulty and loss of time. This instrument can be readily used to analyze virtually any of the hundreds of alloys now in commercial production. MEASUREMENTS OF PROPERTIES The Institute for Materials Research maintains an active measurements program. The principal aims are: (1) production of reference data; (2) development of new measurement methods; and (3) determination of the relationship of bulk properties to the characterization parameters of the material. |