56 research outputs found
Three-dimensional imaging of dislocations in a Ti-35mass%Nb alloy by electron tomography
No full textSato K, Semboshi S, Konno TJ. Three-Dimensional Imaging of Dislocations in a Ti–35mass%Nb Alloy by Electron Tomography. Materials. 2015; 8(4):1924-1933. https://doi.org/10.3390/ma8041924.We have studied three-dimensional (3D) configurations of dislocations in the β phase of a Ti-35mass%Nb alloy by means of single-axis tilt tomography using bright-field scanning transmission electron microscopy (BF-STEM). To visualize dislocations, the hh0 systematic reflections were excited throughout tilt-series acquisition with the maximum tilt angle of 70°. Dislocations in the β grains were clearly reconstructed by the weighted back-projection algorithm. The slip planes of the dislocations were deduced by rotating the reconstructed volumes with the aid of selected area electron diffraction patterns. It was found that BF-STEM images with relatively low contrasts, taken along low-order zone axes, are capable to reproduce and preserve the quality of reconstructed image of dislocations. We also found that tilt angles as low as 40° are practically acceptable to visualize 3D configurations of dislocations, while there exists limitation in resolution due to the existence of a large missing wedge
Effects of Aging Temperature on Electrical Conductivity and Hardness of Cu-3 at. pct Ti Alloy Aged in a Hydrogen Atmosphere
No full textTo improve the balance of the electrical conductivity and mechanical strength for dilute Cu-Ti alloys by aging in a hydrogen atmosphere, the influence of aging temperature ranging from 673 K to 773 K (400 °C to 500 °C) on the properties of Cu-3 at. pct Ti alloy was studied. The Vickers hardness increases steadily with aging time and starts to fall at 3 hours at 773 K (500 °C), 10 hours at 723 K (450 °C), or over 620 hours at 673 K (400 °C), which is the same as the case of conventional aging in vacuum. The maximum hardness increases from 220 to 236 with the decrease of aging temperature, which is slightly lower than aging at the same temperature in vacuum. The electrical conductivity at the maximum hardness also increases from 18 to 32 pct of pure copper with the decrease of the temperature, which is enhanced by a factor of 1.3 to 1.5 in comparison to aging in vacuum. Thus, aging at 673 K (400 °C) in a hydrogen atmosphere renders fairly good balance of strength and conductivity, although it takes nearly a month to achieve. The microstructural changes during aging were examined by transmission electron microscopy (TEM) and atom-probe tomography (APT), it was confirmed that precipitation of the Cu4Ti phase occurs first and then particles of TiH2 form as the third phase, thereby efficiently removing the Ti solutes in the matrix
Formation of Titanium Hydride in Dilute Cu–Ti Alloy by Aging in Hydrogen Atmosphere and Its Effects on Electrical and Mechanical Properties
No full textEffect of aging in hydrogen atmosphere on electrical conductivity of Cu-3at.%Ti alloy
No full textapplication/pdf学術論文 (Article)432680 bytesjournal articl
Thin hydroxyapatite coating on titanium fabricated by chemical coating process using calcium phosphate slurry
No full text
Effects of Second Phases on the Pulverization of Nb<SUB>3</SUB>Al-Base Alloys by Hydrogenation
No full textThree-dimensional imaging of dislocations in a Ti-35mass%Nb alloy by electron tomography
No full textAging of Cu-3 at% Ti Alloys in Hydrogen Atmosphere: Influence of Hydrogen Pressure on Strength and Electrical Conductivity
No full text- …
