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
Multiwalled carbon nanotubes （MWCNTs） reinforced Cu-Sn alloy based nanocomposite was developed by powder metallurgy route. The mass fraction of CNTs was varied from 0 to 2% in a step of 0.5%. The developed nanocompo...Multiwalled carbon nanotubes （MWCNTs） reinforced Cu-Sn alloy based nanocomposite was developed by powder metallurgy route. The mass fraction of CNTs was varied from 0 to 2% in a step of 0.5%. The developed nanocomposites were subjected to density, hardness, electrical conductivity, and friction and wear tests. The results reveal that the density of nanocomposite decreases with the increase of the mass fraction of CNTs. A significant improvement in the hardness is noticed in the nanocomposite with the addition of CNTs. The developed nanocomposites show low coefficient of friction and improved wear resistance when compared with unreinforced alloy. At an applied load of 5 N, the coefficient of friction and wear loss of 2%CNTs reinforced Cu-Sn alloy nanocomposite decrease by 72% and 68%, respectively, compared with those of Cu-Sn alloy. The wear mechanisms of worn surfaces of the composites are reported. In addition, the electrical conductivity reduces with the increase of the content of CNTs.展开更多
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 ℃.
文摘Multiwalled carbon nanotubes （MWCNTs） reinforced Cu-Sn alloy based nanocomposite was developed by powder metallurgy route. The mass fraction of CNTs was varied from 0 to 2% in a step of 0.5%. The developed nanocomposites were subjected to density, hardness, electrical conductivity, and friction and wear tests. The results reveal that the density of nanocomposite decreases with the increase of the mass fraction of CNTs. A significant improvement in the hardness is noticed in the nanocomposite with the addition of CNTs. The developed nanocomposites show low coefficient of friction and improved wear resistance when compared with unreinforced alloy. At an applied load of 5 N, the coefficient of friction and wear loss of 2%CNTs reinforced Cu-Sn alloy nanocomposite decrease by 72% and 68%, respectively, compared with those of Cu-Sn alloy. The wear mechanisms of worn surfaces of the composites are reported. In addition, the electrical conductivity reduces with the increase of the content of CNTs.
