Papers by Keyword: Aluminum Matrix

Abstract: In this study, functionally gradient aluminum reinforced by Silicon carbide particles (FGMSiCp/Al) composites are prepared by microwave sintering and pressureless sintering processing. The sintering behaviors, mechanical properties of composites were measured, and microstructure was observed by optical microscope and SEM. The results showed that the density of sintered samples which prepared by microwave sintering were better than that presureless sintering one. The highest density of sintered sample by microwave sintering reached 2.64 g/cm3, the relative density was 95.65%. Whatever preparing process, the mechanical properties of sintered samples were related to the temperature. The distribution of silicon carbide particles is uniform in the aluminum matrix, however, slight agglomeration can be observed. The interface between other layers is not obvious except interface between Al and 5% SiC/Al layer.

Abstract: This paper examines the stress distribution around a fiber break in alumina-fiber reinforced aluminum matrix (Al2O3/Al) composites using finite element analysis and predicts the tensile strength using tensile failure simulations. In particular, we discuss the effect of the matrix hardening on the tensile failure of the Al2O3/Al composites. First, we clarify the differences in the stress distribution around a fiber break between an elastic-perfect plastic matrix and an elastic-plastic hardening matrix using finite element analysis. Second, the procedure for simulating fiber damage evolution in the Al2O3/Al composites is presented. The simulation incorporates the analytical solution for the axial fiber stress distribution of a broken fiber in the spring element model for the stress analysis of the whole composite. Finally, we conduct Monte Carlo simulations of fiber damage evolution to predict the tensile strength of the Al2O3/Al composites, and discuss the effect of matrix hardening on the tensile strength of the Al2O3/Al composites. Coupled with size-scaling analysis, the simulated results express the size effect on the strength of the composites, which is seen in experimental results.

Abstract: Diffusion of nanosized liquid Pb inclusions attached to dislocations in thin aluminum foils was investigated in a wide temperature range using in-situ transmission electron microscopy. Trajectories of motion of the inclusions along the dislocations were used to determine their diffusion coefficients. The temperature and size dependences of diffusion coefficients of the inclusions were obtained. They indicate that (i) studied inclusions hold {111} facets on their surface in the studied temperature range; (ii) the mobility of the inclusions is controlled by step nucleation at the {111} facets.