Effect of the MgO particles on the nanocrystalline copper grain stability

Thermal stability of the nanostructure of mechanically milled Cu–5 vol% Al2O3 nanocomposite powder particles

“…6, 7, and 9, a fraction of the Al 2 O 3 particles of the as-milled powder particles coarsen and their sizes reach a level larger than 100 nm after annealing at 600°C for 5 h. These large Al 2 O 3 particles are less effective in dragging the migration of grain boundaries and thus allow faster grain growth than Al 2 O 3 nanoparticles smaller than 50 nm during annealing. 30 As a result, some grains adjacent to large Al 2 O 3 particles grew abnormally, as shown in Fig. 4(b).…”

Grain and nanoparticle coarsening of an ultrafine structured Cu–5vol.%Al2O3 nanocomposite during isochronal annealing

“…No measurable Cu grain growth was observed during annealing in these temperature ranges. A study conducted by Ď urišin et al [12] showed that the recrystallization of an ultrafine structured Cu-3 vol.%MgO nanocomposite also occurred at a low temperature of $300°C, and abnormal growth of Cu grains occurred at temperatures above 500°C. Recently, we [13] investigated the microstructural stability of mechanically milled nanostructured Cu-5 vol.%Al 2 O 3 powder particles during annealing in the temperature range of 300-600°C, and found that the nanostructured Cu matrix can still maintain their nanometer sized grains after annealing at 600°C for 5 h due to the retardation of Al 2 O 3 nanoparticles on grain growth.…”

Effect of Reinforcement Volume Fraction on the Mechanical Properties of Al—SiC Nanocomposites Produced by Mechanical Alloying and Consolidation

“…The residual porosity was removed by performing the second press/ sintering cycle. Meanwhile, the analysis of the crystallite size by XRD revealed the significant effect of SiC particles on the grain growth, owing to the influence of reinforcement particles on grain boundary energy and its mobility [20]. This effect becomes more pronounced as the SiC content increases due to more pinning sites.…”

“…The possible sources for the presence of oxide particles are (i) reaction between the aluminum with stearic acid used as PCA [27], (ii) the oxide film covering the surface particles of the gas atomized Al powder, and (iii) abrasion of the balls during milling. Reports [20] show that the particle size of alumina particles arise from milling is smaller than 100 nm. The importance of surface oxide layers on the mechanical properties of cryomilled Al alloys has been reported by Witkin and Lavernia [28].…”