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Samples of a diluted dispersion-strengthening alloy of the Cu-Cr-Zr system were processed with a combination of some severe plastic deformation methods. Preliminary, the samples were quenched into water from a pre-melting temperature to create a supersaturated solid solution concentration. In the course of the experiment the average sizes and distribution density of particles with different chemical compositions undergo an evolution that indicates that phase transformations occur even during the cold deformation. A decomposition of the solid solution due to the deformation-induced acceleration of diffusion certainly contributes to this evolution, but the whole complex of the observed results cannot be explained only with this relatively well-studied phenomenon and implies the presence of the deformation-induced dissolution of the second-phase particles. A possible mechanism of the dissolution linking this process to a mechanical fragmentation of the particles in the course of severe plastic deformation is discussed. A dependence of the dissolution efficiency on the composition and related morphology of the particles was also noted. A conclusion on the simultaneously occurring of the kinetically opposite phase transitions is also confirmed by an observation of changes in the lattice constant of copper matrix that are non-monotonous versus the accumulated strain. The crystalline structure refinement upon the severe plastic deformation proceeds through selforganization of dense dislocation pileups into grain boundaries what implies a reverse influence of the second-phase particles, which are effective obstacles to dislocation motion, on the structural transformations. Thus, there exists an interdependence between strain mechanisms and phase transitions such as the second phase particles precipitation and their dissolution in the copper matrix that influences the structure refinement, the dispersion particles distribution in the bulk and, consequently, the strength and other properties of the material. This influence may be especially complicated in alloys that like the one under study have a second phase consisted of particles of many different compositions.

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In this work the possibility of using TiO2 coating as a barrier between carbon fiber and an aluminum matrix in a Cf/Al composite was studied. Specimens of a composite with a matrix of Al-6Mg alloy were obtained by the method of liquid-phase infiltration under pressure. As a reinforcing component was used continuous uncoated and titanium dioxide coated carbon fibers. TiO2 coating on carbon fiber preform were prepared by sol–gel method. The protective properties of the coating and the mechanical properties of the composite at three-point bending were evaluated. Microstructural and fractographic analyzes were performed. It was established that the barrier coating made it possible to increase the strength of the composite more than 2.5 times from 250 MPa to 660 MPa.