scholarly journals Diffusion Bonding of Ti6Al4V to Al2O3 Using Ni/Ti Reactive Multilayers

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 655
Author(s):  
Marcionilo Silva ◽  
Ana S. Ramos ◽  
M. Teresa Vieira ◽  
Sónia Simões
Keyword(s):  
Thin Films ◽  
Diffusion Bonding ◽  
Mechanical Characterization ◽  
Base Material ◽  
Microstructural Characterization ◽  
Multilayer Thin Films ◽  
X Ray ◽  
Distribution Maps ◽  
Base Materials

This paper aims to investigate the diffusion bonding of Ti6Al4V to Al2O3. The potential of the use of reactive nanolayered thin films will also be investigated. For this purpose, Ni/Ti multilayer thin films with a 50 nm modulation period were deposited by magnetron sputtering onto the base materials. Diffusion bonding experiments were performed at 800 °C, under 50 MPa and a dwell time of 60 min, with and without interlayers. Microstructural characterization of the interface was conducted through scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS). The joints experiments without interlayer were unsuccessful. The interface is characterized by the presence of a crack close to the Al2O3 base material. The results revealed that the Ni/Ti reactive multilayers improved the diffusion bonding process, allowing for sound joints to be obtained at 800 °C for 60 min. The interface produced is characterized by a thin thickness and is mainly composed of NiTi and NiTi2 reaction layers. Mechanical characterization of the joint was assessed by hardness and reduced Young’s modulus distribution maps that enhance the different phases composing the interface. The hardness maps showed that the interface exhibits a hardness distribution similar to the Al2O3, which can be advantageous to the mechanical behavior of the joints.

scholarly journals Joining Ti6Al4V to Alumina by Diffusion Bonding Using Titanium Interlayers

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1728
Author(s):  
Marcionilo Silva ◽  
Ana S. Ramos ◽  
Sónia Simões
Keyword(s):  
Thin Films ◽  
Shear Strength ◽  
Diffusion Bonding ◽  
Electron Backscatter Diffraction ◽  
Young Modulus ◽  
Microstructural Characterization ◽  
Ti6al4v Alloy ◽  
Distribution Maps ◽  
Average Shear Strength

This work aims to investigate the joining of Ti6Al4V alloy to alumina by diffusion bonding using titanium interlayers: thin films (1 µm) and commercial titanium foils (5 µm). The Ti thin films were deposited by magnetron sputtering onto alumina. The joints were processed at 900, 950, and 1000 °C, dwell time of 10 and 60 min, under contact pressure. Experiments without interlayer were performed for comparison purposes. Microstructural characterization of the interfaces was conducted by optical microscopy (OM), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), and electron backscatter diffraction (EBSD). The mechanical characterization of the joints was performed by nanoindentation to obtain hardness and reduced Young’s modulus distribution maps and shear strength tests. Joints processed without interlayer have only been achieved at 1000 °C. Conversely, joints processed using Ti thin films as interlayer showed promising results at temperatures of 950 °C for 60 min and 1000 °C for 10 and 60 min, under low pressure. The Ti adhesion to the alumina is a critical aspect of the diffusion bonding process and the joints produced with Ti freestanding foils were unsuccessful. The nanoindentation results revealed that the interfaces show hardness and reduced Young modulus, which reflect the observed microstructure. The average shear strength values are similar for all joints tested (52 ± 14 MPa for the joint processed without interlayer and 49 ± 25 MPa for the joint processed with interlayer), which confirms that the use of the Ti thin film improves the diffusion bonding of the Ti6Al4V alloy to alumina, enabling a decrease in the joining temperature and time.

scholarly journals Microstructural Characterization of Dissimilar Titanium Alloys Joints Using Ni/Al Nanolayers

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 715 ◽  
Author(s):  
Sónia Simões ◽  
Filomena Viana ◽  
Ana Ramos ◽  
M. Vieira ◽  
Manuel Vieira
Keyword(s):  
Titanium Alloys ◽  
Diffusion Bonding ◽  
Base Material ◽  
Microstructural Characterization ◽  
Thin Layers ◽  
Electron Microscopies ◽  
Base Materials ◽  
Material Surfaces ◽  
Scanning Electron

This study demonstrates the potential of the use of Ni/Al nanolayers for joining dissimilar titanium alloys. For this purpose, a detailed microstructural characterization of the diffusion bonding interfaces of TiAl to Ti6Al4V, TiAl to TiNi and TiNi to Ti6Al4V was carried out. The nanolayers (alternated aluminum and nickel (Ni-7V wt.%) layers) were deposited onto the base material surfaces. Diffusion bonding was performed at 700 and 800 °C under pressures ranging from 5 to 40 MPa and at dwell times between 60 and 180 min. Microstructural characterization was performed using high resolution transmission and scanning electron microscopies. The results revealed that dissimilar titanium joints (TiAl to Ti6Al4V, TiAl to TiNi and TiNi to Ti6Al4V) assisted by Ni/Al nanolayers can be obtained successfully at 800 °C for 60 min using a pressure of 20 MPa. The bond interfaces are thin (less than 10 µm) and mainly composed of NiAl grains with a few nanometric grains of Al8V5. Thin layers of Al-Ni-Ti intermetallic compounds were formed adjacent to the base materials due to their reaction with the nanolayers.

scholarly journals Joining Alumina to Titanium Alloys Using Ag-Cu Sputter-Coated Ti Brazing Filler

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4802
Author(s):  
Omid Emadinia ◽  
Aníbal Guedes ◽  
Carlos José Tavares ◽  
Sónia Simões
Keyword(s):  
Microstructural Characterization ◽  
Interface Bonding ◽  
Soft Or ◽  
Tial Alloys ◽  
X Ray ◽  
Distribution Maps ◽  
Ti Oxides ◽  
Ti Alloys ◽  
Central Regions

The joining of alumina (Al2O3) to γ-TiAl and Ti6Al4V alloys, using Ag-Cu sputter-coated Ti brazing filler foil, was investigated. Brazing experiments were performed at 980 °C for 30 min in vacuum. The microstructure and chemical composition of the brazed interfaces were analyzed by scanning electron microscopy and by energy dispersive X-ray spectroscopy, respectively. A microstructural characterization of joints revealed that sound multilayered interfaces were produced using this novel brazing filler. Both interfaces are composed mainly of α-Ti, along with Ti2(Ag,Cu) and TiAg intermetallics. In the case of the brazing of γ-TiAl alloys, α2-Ti3Al and γ-TiAl intermetallics are also detected at the interface. Bonding to Al2O3 is promoted by the formation of a quite hard Ti-rich layer, which may reach a hardness up to 1872 HV 0.01 and is possibly composed of a mixture of α-Ti and Ti oxides. Hardness distribution maps indicate that no segregation of either soft or brittle phases occurs at the central regions of the interfaces or near the base Ti alloys. In addition, a smooth hardness transition was established between the interface of Al2O3 to either γ-TiAl or Ti6Al4V alloys.

Microstructure Characterization of Si/C Multilayer Thin Films

2013 ◽  
Vol 743-744 ◽  
pp. 910-914
Author(s):  
Ting Han ◽  
Geng Rong Chang ◽  
Yun Jin Sun ◽  
Fei Ma ◽  
Ke Wei Xu
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Post Annealing ◽  
Transmission Electron ◽  
Twin Defects ◽  
Modulation Ratio

Si/C multilayer thin films were prepared by magnetron sputtering and post-annealing in N2 atmosphere at 1100 for 1h. X-ray diffraction (XRD), Raman scattering and high-resolution transmission electron microscopy (HRTEM) were applied to study the microstructures of the thin films. For the case of Si/C modulation ratio smaller than 1,interlayer diffusion is evident, which promotes the formation of α-SiC during thermal annealing. If the modulation ratio is larger than 1, the Si sublayers are partially crystallized, and the thicker the Si sublayers are, the crystallinity increases. To be excited, brick-shaped nc-Si is directly observed by HRTEM. The brick-shaped nc-Si appears to be more regular near the Si (100) substrate but with twin defects. The results are instructive in the application of solar cells.

Bidimensional X-ray Diffraction Analysis for Structural and Microstructural Characterization of Lanthanum Manganite Thin Films

2004 ◽  
Vol 108 (17) ◽  
pp. 5189-5191
Author(s):  
Ivano Alessandri ◽  
Marcello Gelfi ◽  
Elza Bontempi ◽  
Roberto Roberti ◽  
Laura E. Depero
Keyword(s):  
Thin Films ◽  
Diffraction Analysis ◽  
Microstructural Characterization ◽  
Lanthanum Manganite ◽  
X Ray Diffraction ◽  
X Ray

Microstructural characterization of Y-Ba-Cu-O laser deposited with high deposition rates on SrTiO3

1990 ◽  
Vol 48 (4) ◽  
pp. 56-57
Author(s):  
T.S. Ravi ◽  
R. Ramesh ◽  
D.M. Hwang ◽  
X.D. Wu ◽  
A. Inam ◽  
...  
Keyword(s):  
Thin Films ◽  
Microstructural Characterization ◽  
Industrial Applications ◽  
Laser Deposition ◽  
Processing Conditions ◽  
Deposition Rates ◽  
X Ray ◽  
Very High

As the technique of pulsed-laser deposition of YBa2Cu3O7−x (YBCO) matures, it is important to be able to have economically feasible processing conditions for future industrial applications such as microelectronics. Very high quality thin films of YBCO (with excellent Tc and Jc) have been consistently obtained for low deposition rates, such as 0.3Å/sec. However at this rate it takes at least two hours to produce a film 2000Å thick. While the quality of the film grown is of prime importance, it would be economically advantageous if the film can be grown much faster without much loss in quality. The objective of this study is to microstructurally characterize, using a combination of microdiffraction, X-ray microanalysis and HREM, thin films of YBCO prepared with higher deposition rates.

Nondestructive Characterization of Multilayer Thin Films by X-ray Reflectivity

1994 ◽  
Vol 38 ◽  
pp. 139-143
Author(s):  
T. C. Huang
Keyword(s):  
Thin Films ◽  
Layer Structure ◽  
Annealing Effect ◽  
Multilayer Thin Films ◽  
X Ray ◽  
Si Substrates ◽  
Specular Reflectivity ◽  
Reflectivity Data ◽  
Nondestructive Characterization

Abstract The X-ray reflectivity technique was used to study the annealing effect on layer structure of Ta/FeMn/NiFe/Cu/NiFe/Ta multilayer thin films on Si substrates. High-resolution specular reflectivity data were collected and analyzed by least-squares refinement. Results on layer thickness, density and roughness were obtained and correlated with the magnetic properties of the films.

Sign in / Sign up

Export Citation Format

Share Document