The influence of the structural state of the reinforcing nanoparticles on the mechanical properties of the alloy Al94Fe2,5Cr2,5Ti1


I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Krzhizhanovsky str., 3, Kyiv, 03142, Ukraine
Electron Microscopy and Strength of Materials - Kiev: Frantsevich Institute for Problems of Materials Science NASU, 2013, #19


The effects of production conditions of Al94Fe2,5Cr2,5Ti1 extruded strips on its structure and mechanical properties were studied. Strips with cross-section of 4 x 15 mm were obtained without sintering by compacting and subsequent extrusion of powders produced by water atomization technique. At extrusion temperature of 400 °C the two-phase structure of the water atomized powders (Al matrix and reinforcing nanoquasicrystaline phase) remained unchanged. Further increase in extrusion temperature reduced the content of quasicrystalline reinforcing particles gradually; the part of them transformed into a crystalline state. Quasicrystalline particles are completely absent in the material obtained at extrusion temperature of 450 °C. The results of mechanical test give reason to assume that the mechanical properties of this alloy are mainly determined by the structural state of the reinforcing particles (quasicrystalline or crystalline). Strengthening of aluminum matrix by nanoquasicrystalline particles provides the plasticity δ of the alloy above 5%. On the contrary, strengthening by intermetallic particles reduces the plasticity of the alloy to values δ < 1%. This result confirms the idea regarding significant plasticity of quasicrystals at local loading. This local plasticity allows relaxing the stresses arisen in aluminum matrix at deformation of the alloy. Full text download