Production of new and conventional metallic materials and their characterization by ultrasonic and metallographic methods

The investigations of this project were realized by proposed program. As an initial material the powder metallic particle was used and other metallic materials obtained by conventional procedure in the domicile metallic industry. The metals in powder (Ti, Ni, Cu, Fe) were got from the companies MERCK and FLUKA. According to the methods of the powder metallurgy (first mixed, after that compacted and densified) the samples for need investigations were prepared. In this case (with special procedure; homogenization, pressing and sintering) new porous materials were produced, with defined geometry and with characteristic properties, most interesting as both theoretical and applied aspects. The ultrasonic and metallographic characterization and some other examination were made on this materials. The materials, steel and aluminium, were obtained in domicile factories which produced and manufactured this conventional materials. The choice of this material is selected by defined technological procedure, needed for obtaining correlation between microstructure and macroscopic properties of the examined materials. For the examination on the influence of the different concentration of the components, as a thermal and mechanical treatment, metallographic analyze in the examined materials was made. The ultrasonic investigations in previous noted materials were made in isothermal and in some special case in nonisothermal conditions. For this purpose special equipment was constructed with possibility to program changing of the temperature. From the experimental measured values of the density and velocities of ultrasound, by relationship from theory of elasticity the modulus of elasticity (E, K and G) and Poisson's ratio are determined. In this case it is possible to obtain complete information of the elastic state on the examined materials - most important characteristic in examination of the materials with shape memory effect. Finally in this project the special attention was made in the examination of the structure by theoretical aspects. By using physical models on which metallographic methods are used, a quantitative analyze is done on a mathematical-physical bases. By mathematical procedure stereo logical parameters were defined which characterized isotropic structure by method applied in quantitative metallographic analyze. (Original)