Computer technologies in metal science

Abstract

The rapid growth of computer power, the possibilities of software, and the volume of data bases have increased the role of information technologies in applied sciences and production. Thirty-years of experience in using computers at the Department of Metals Science and Strength Physics of the Moscow Institute of Steel and Alloys allows us to consider trends in the advancement of computer methods in metal science for research, production, and training students.One traditional field of computer applications consists of the processing of experimental data. Modern software creates the illusion that it is possible to obtain any volume of data of any accuracy from any measurement. For example, numerical methods can be used to break any curve into any number of "peaks" with specified coordinates. However, the results will not reflect the actual reality. An experiment always gives a value of some quantity at a finite number of points with an inevitable random error at each point. These errors are "inherited" in errors of the final values, placing a limit; processing makes sense only when the parameters found exceed their own error. This statement of the problem leads to the principle of maximum likelihood, which guarantees minimum random errors of the result. With allowance for the possible limits in analyzing spectra [1], it became possible to create effective programs for separating components in multiplets of x-ray diffraction lines for analyzing the biphase decomposition of martensite [2] and then more complex M6ssbauer spectra [3] and, finally, for solving the problem of the distribution function of orientations in analyzing textures with the corresponding optimum design of experiment [4,5]. In this multi-dimensional problem the method of maximum likelihood allowed researchers to find the possible limits in measuring textures depending on the laboriousness of the photography.I The authors and the collective of the department express their gratitude to S. G. Babakov for many years of work on introducing computer technologies. 168Specifically+ an analysis of M6ssbauer spectra has shown that carbon martensite at room temperature possesses a strong close-range order when pairs of carbon atoms occupy adjacent octahedral interstices [3]. The structure of multiplets in diffractometry has been used to study self-tempering in quenching, the biphase decomposition in low-temperature tempering and cold deformation, and the effect of alloying and heat treatment on the decomposition of martensite [6].Microprocessor equipment has made it possible to create methods of study that had been impossible earlier because of the volume and laboriousness of "manual" measurements and subsequent preparation of the data for computer processing. Automatized means have been created for measuring and controlling the experiment and for direct input of the information in a digital form and processing it in the real time mode.Although the first measurements of the microrelief of two halves of a fracture, which give the history of crack propagation a...