Using Al Mg and Al Mg Y alloys as raw materials and nitrogen as gas reactants, AlN powders and composite AlN powders by in situ synthesis method were prepared. AlN lumps prepared by the nitriding of Al Mg and Al ...Using Al Mg and Al Mg Y alloys as raw materials and nitrogen as gas reactants, AlN powders and composite AlN powders by in situ synthesis method were prepared. AlN lumps prepared by the nitriding of Al Mg and Al Mg Y alloys have porous microstructure, which is favorable for pulverization. They have high purity, containing 1.23%(mass fraction) oxygen impurity, and consisted of AlN single phase. The average particle size of AlN powders is 6.78 μm. Composite AlN powders consist of AlN phases and rare earth oxide Y 2O 3 phase. The distribution of particle size of AlN powders shows two peaks. In view of packing factor, AlN powders with such size distribution can easily be sintered to high density.展开更多
Nanometer aluminum nitride powder with purity higher than 98wt% and diameter in the range of 5-80nm has been obtained by microwave heating using α-Al2O3、Al(OH)3、 colloidal Al(OH)3 as the source for aluminum, and ph...Nanometer aluminum nitride powder with purity higher than 98wt% and diameter in the range of 5-80nm has been obtained by microwave heating using α-Al2O3、Al(OH)3、 colloidal Al(OH)3 as the source for aluminum, and phenolformaldehyde resin, char, nanometer carbon black powder as the source for carbon, respectively. The effect of the type of starting materials and synthesis conditions on the purity and the size of the nanometer AlN powder has been analyzed in this paper.展开更多
Powder metallurgy method was used to prepare copper alloy nanocomposites （CuZr/AlN） with high strength and conductivity. Optical microscopy, high-resolution transmission electron microscopy and other methods were ad...Powder metallurgy method was used to prepare copper alloy nanocomposites （CuZr/AlN） with high strength and conductivity. Optical microscopy, high-resolution transmission electron microscopy and other methods were adopted to study the impact of different sintering technologies on the structural and mechanical properties as well as the impact of solution and aging treatments on the mechanical properties of CuZr/AlN. The result shows that the specimen has a dense structure, and the size of the crystal grain is around 0.2 μm. The Brinell hardness of the specimen increases with the increase in re-pressing pressure and sintering temperature. The Brinell hardness of specimen also increases with the increase in zirconium content. However, above 0.5%（mass fraction） of zirconium content, the Brinell hardness of the nanocomposites is reduced. The buckling strength of the specimens increases with the increase in re-pressing pressure and sintering temperature. The buckling strength is the highest when the zirconium content is 0.5%. The Brinell hardness is lower after solution and aging treatments at 900 ℃. The Brinell hardness of the CuZr/AlN series specimen after the aging treatment at 500 ℃ or 600 ℃ increases. The specimen was also over aged at 700 ℃.展开更多
文摘Using Al Mg and Al Mg Y alloys as raw materials and nitrogen as gas reactants, AlN powders and composite AlN powders by in situ synthesis method were prepared. AlN lumps prepared by the nitriding of Al Mg and Al Mg Y alloys have porous microstructure, which is favorable for pulverization. They have high purity, containing 1.23%(mass fraction) oxygen impurity, and consisted of AlN single phase. The average particle size of AlN powders is 6.78 μm. Composite AlN powders consist of AlN phases and rare earth oxide Y 2O 3 phase. The distribution of particle size of AlN powders shows two peaks. In view of packing factor, AlN powders with such size distribution can easily be sintered to high density.
文摘Nanometer aluminum nitride powder with purity higher than 98wt% and diameter in the range of 5-80nm has been obtained by microwave heating using α-Al2O3、Al(OH)3、 colloidal Al(OH)3 as the source for aluminum, and phenolformaldehyde resin, char, nanometer carbon black powder as the source for carbon, respectively. The effect of the type of starting materials and synthesis conditions on the purity and the size of the nanometer AlN powder has been analyzed in this paper.
基金Project(KJ2013A227)supported by the Natural Science Research Key Projects of Anhui Provincial Universities,ChinaProject(51104051)supported by the National Natural Science Foundation of ChinaProject(11C26213401903)supported by Innovation Fund for Small and Medium Technology Based Firms,China
文摘Powder metallurgy method was used to prepare copper alloy nanocomposites （CuZr/AlN） with high strength and conductivity. Optical microscopy, high-resolution transmission electron microscopy and other methods were adopted to study the impact of different sintering technologies on the structural and mechanical properties as well as the impact of solution and aging treatments on the mechanical properties of CuZr/AlN. The result shows that the specimen has a dense structure, and the size of the crystal grain is around 0.2 μm. The Brinell hardness of the specimen increases with the increase in re-pressing pressure and sintering temperature. The Brinell hardness of specimen also increases with the increase in zirconium content. However, above 0.5%（mass fraction） of zirconium content, the Brinell hardness of the nanocomposites is reduced. The buckling strength of the specimens increases with the increase in re-pressing pressure and sintering temperature. The buckling strength is the highest when the zirconium content is 0.5%. The Brinell hardness is lower after solution and aging treatments at 900 ℃. The Brinell hardness of the CuZr/AlN series specimen after the aging treatment at 500 ℃ or 600 ℃ increases. The specimen was also over aged at 700 ℃.
