The color of Cu Mn Zn alloys is quantitatively researched using the CIE L * a * b * color system. The color parameters such as L *, a * and b * are employed to describe the color and are measured by a spectrophotomete...The color of Cu Mn Zn alloys is quantitatively researched using the CIE L * a * b * color system. The color parameters such as L *, a * and b * are employed to describe the color and are measured by a spectrophotometer. Based on the color data of 46 experimental alloys, a series of formulae are established to correlate color parameters changed with the alloy composition. Therefore, the color of the ternary Cu Mn Zn alloys can be calculated and forecast easily. The results show that Mn plays a more important role in the color of Cu Mn Zn alloys than Zn does. In particular, the chroma values of ternary Cu Mn Zn alloys mainly depend on the Mn content.展开更多
The thin films of pure Cu and Cu-2.18%Cr(mole fraction,%) were deposited on Si(100) substrates. Then the samples were vacuum-annealed at 573-773 K to investigate the effect of Cr on the microstructural and electrical ...The thin films of pure Cu and Cu-2.18%Cr(mole fraction,%) were deposited on Si(100) substrates. Then the samples were vacuum-annealed at 573-773 K to investigate the effect of Cr on the microstructural and electrical characteristics of Cu/Si systems. The XRD results reveal that the annealed Cu(Cr) film has a strong(111) texture. The results of AFM and FESEM indicate that the Cu(Cr) films with insoluble Cr have compact surface morphology and fine columnar microstructure. Upon annealing,most Cr segregates at the surface and interface. The residual insoluble Cr is enriched in amorphous structure between Cu grains and retards the crystallization of annealed Cu(Cr) films. As a result,the minimal annealing resistivity of the Cu-2.18%Cr film is 2.76 μΩ·cm at 773 K,which approaches to 2.55 μΩ·cm of the Cu film at 673 K. Significant changes in the microstructure and properties are obtained by adding Cr to Cu films after annealing.展开更多
By using high temperature optical microscopy, oxidation behaviors of poly- and single crystalline NbSi2 were observed in-situ at 1023 K. The effects of micro-cracks, porosity and grain boundary on the oxidation behavi...By using high temperature optical microscopy, oxidation behaviors of poly- and single crystalline NbSi2 were observed in-situ at 1023 K. The effects of micro-cracks, porosity and grain boundary on the oxidation behavior of NbSi2 have been studied. The results indicate that new cracks initiate and extend from the pre-existing cracking areas in the arc-melted poly-crystalline specimen, leading to fragmentation after 220 min at 1023 K. However, although pores and grain boundary are the preferential oxidation site, they do not directly lead to fragmentation during oxidation, indicating that the pre-existing cracks in specimen are the key reason to pesting. The oxidation kinetics of the studied NbSi2 specimens corresponds well with the in-situ observation.展开更多
文摘The color of Cu Mn Zn alloys is quantitatively researched using the CIE L * a * b * color system. The color parameters such as L *, a * and b * are employed to describe the color and are measured by a spectrophotometer. Based on the color data of 46 experimental alloys, a series of formulae are established to correlate color parameters changed with the alloy composition. Therefore, the color of the ternary Cu Mn Zn alloys can be calculated and forecast easily. The results show that Mn plays a more important role in the color of Cu Mn Zn alloys than Zn does. In particular, the chroma values of ternary Cu Mn Zn alloys mainly depend on the Mn content.
基金Project (0525) supported by the Shanghai Research Development Fund of Applied Materials
文摘The thin films of pure Cu and Cu-2.18%Cr(mole fraction,%) were deposited on Si(100) substrates. Then the samples were vacuum-annealed at 573-773 K to investigate the effect of Cr on the microstructural and electrical characteristics of Cu/Si systems. The XRD results reveal that the annealed Cu(Cr) film has a strong(111) texture. The results of AFM and FESEM indicate that the Cu(Cr) films with insoluble Cr have compact surface morphology and fine columnar microstructure. Upon annealing,most Cr segregates at the surface and interface. The residual insoluble Cr is enriched in amorphous structure between Cu grains and retards the crystallization of annealed Cu(Cr) films. As a result,the minimal annealing resistivity of the Cu-2.18%Cr film is 2.76 μΩ·cm at 773 K,which approaches to 2.55 μΩ·cm of the Cu film at 673 K. Significant changes in the microstructure and properties are obtained by adding Cr to Cu films after annealing.
基金Provision of high purity raw elements from Kyoto University is appreciated. This work was supported by the National Natural Science Foundation of China (Grant No. 50131030).
文摘By using high temperature optical microscopy, oxidation behaviors of poly- and single crystalline NbSi2 were observed in-situ at 1023 K. The effects of micro-cracks, porosity and grain boundary on the oxidation behavior of NbSi2 have been studied. The results indicate that new cracks initiate and extend from the pre-existing cracking areas in the arc-melted poly-crystalline specimen, leading to fragmentation after 220 min at 1023 K. However, although pores and grain boundary are the preferential oxidation site, they do not directly lead to fragmentation during oxidation, indicating that the pre-existing cracks in specimen are the key reason to pesting. The oxidation kinetics of the studied NbSi2 specimens corresponds well with the in-situ observation.
