The powerful combination of ion-milling method for XTEM preparation: Application to a diffusion barrier coating on Nb substrate

2012 ◽  
Author(s):  
Eni Sugiarti ◽  
Youming Wang ◽  
Somei Ohnuki
Keyword(s):  
Diffusion Barrier ◽  
Ion Milling ◽  
Barrier Coating ◽  
Milling Method

Formation of diffusion barrier coating on superalloy 690 substrate and its stability in borosilicate melt at elevated temperature

2013 ◽  
Vol 432 (1-3) ◽  
pp. 72-77 ◽  
Author(s):  
R.S. Dutta ◽  
C. Yusufali ◽  
B. Paul ◽  
S. Majumdar ◽  
P. Sengupta ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Diffusion Barrier ◽  
Barrier Coating

Optimization of Cross Sectioning for Solder Joint using Broad Ar Ion Beam Milling with Temperature Control

2020 ◽  
Author(s):  
Natsuko Asano ◽  
Tamae Omoto ◽  
Jinfeng Lu ◽  
Hirobumi Morita ◽  
Natasha Erdman ◽  
...  
Keyword(s):  
Melting Point ◽  
Solder Joint ◽  
Sample Preparation ◽  
Semiconductor Manufacturing ◽  
Thermal Damage ◽  
Ion Beam ◽  
The Other ◽  
Ion Milling ◽  
Milling Method ◽  
Liquid Nitrogen Cooling

Abstract Understanding solder joints is very important for failure analysis in semiconductor manufacturing because it is commonly used for mounting semiconductor devices on boards. However, regarding sample preparation for analysis, solder poses challenges in crosssection preparation due to the differences in melting point and hardness of its constituents. Therefore, precision cutting methods such as ion milling are required. On the other hand, ion milling method usually causes thermal damage during cutting. In this paper, we tried to optimize the sample temperature during Ar ion milling using liquid nitrogen cooling [1].

Creep Deformation / Oxidation Behavior of Re-Cr-Ni Diffusion Barrier Coated Hastelloy-X at 970°C in Air

2008 ◽  
Vol 595-598 ◽  
pp. 107-116 ◽  
Author(s):  
Shigenari Hayashi ◽  
Mikihiro Sakata ◽  
Shigeharu Ukai ◽  
Toshio Narita
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Barrier Layer ◽  
Creep Deformation ◽  
Diffusion Barrier ◽  
Hastelloy X ◽  
Alloy Substrate ◽  
Barrier Coating ◽  
Diffusion Barrier Layer ◽  
Coated Alloy

High temperature oxidation / creep deformation behavior of a diffusion barrier coated Hastelloy-X alloy, with large grain size ~500μm, was investigated at 970°C in air with external tensile stress of 22.5, 27.5, 32, and 40MPa. The diffusion barrier coating formed on Hastelloy-X consisted of a duplex structure with an inner diffusion barrier layer of Re-Cr-Ni alloy, and an outer oxidation resistant layer of β-NiAl. Un coated bare Hastelloy-X alloy with same grain size was also examined under the same conditions for comparison. The composition of the as-coated diffusion barrier coating was (15~21)Ni, (33~37)Cr, (30~33)Re, (11~15)Mo, and (9~14)Fe. This composition corresponds to σ-phase in the Ni-Cr-Re ternary system, which is known as a topologically close packed, TCP phase. The composition of this diffusion barrier layer did not change during the experiment. The oxide scales formed after creep testing on the coated and un-coated alloy surfaces were needle-like θ-Al2O3, and Cr2O3 with small amount of FeCr2O4, respectively. Grain boundary oxidation was also found in the subsurface region of the un-coated alloy. The Al2O3 scale exhibited severe spallation, and many cracks were formed perpendicular to the stress direction. However, no spallation or cracks were observed in the Cr2O3. The creep rupture times for the diffusion barrier coated alloy were about 1.5 times longer than those for bare alloy at all creep stress conditions. The fracture surface after rupture indicates that fracture occurred along alloy grain boundaries in both the coated and un-coated alloy substrate. Many cavities and cracks were observed within the diffusion barrier coated alloy substrate. These cavities and cracks tended to propagate from the substrate toward the diffusion barrier layer, and then stopped at the Re-Cr-Ni / β-NiAl interface. Cracks formed in the un-coated alloy initiated at the tip of grain boundary oxides, and propagated into alloy substrate. However no major cavities were observed inside the alloy substrate. The stress index, n, for both specimens was about 6, and this indicates that the deformation mechanism of both samples was dislocation creep. These results suggest that the Re-Cr-Ni diffusion barrier layer acts as a barrier against the movement of dislocations at the interface with the alloy surface.

Formation Process of a Rhenium-Based Diffusion Barrier on a Nickel-Based Superalloy

2006 ◽  
Vol 980 ◽  
Author(s):  
Yongming Wang ◽  
Somei Ohnuki ◽  
Toshio Narita
Keyword(s):  
Diffusion Barrier ◽  
Formation Process ◽  
Xrd Analysis ◽  
Solubility Limit ◽  
Film Structure ◽  
Barrier Films ◽  
Electron Probe Micro Analyzer ◽  
Nickel Based Superalloy ◽  
Barrier Coating ◽  
Barrier Film

AbstractThe formation process of Rhenium-based diffusion barrier coating on Nickel-based superalloy has been investigated in present paper. The diffusion barrier can be formed by two steps, electroplating and Cr cementation. A tri-layer film structure consisting of Ni / Re~63Ni~37 / Ni was prepared by electrolytic plating onto the substrate of a Ni-based single-crystal superalloy, it was found that the Re-Ni plating film composed of amorphous alloy which is characterized by X-ray diffraction (XRD) analysis. The changes of the barrier films which formed by followed Cr-Pack cementations at 1573 K for 20 min, 50 min, 240 min, 360 min and 600 min, respectively, were investigated by Scan Electron Microscope (SEM) and Electron Probe Micro Analyzer (EPMA). Changing in the thickness of barrier film exhibited two stages, and the composition of barrier film changed along the curve of solubility limit of Ni in Re-Ni-Cr sigma phase.

Advanced Coatings on High Temperature Applications

2006 ◽  
Vol 522-523 ◽  
pp. 1-14 ◽  
Author(s):  
Toshio Narita ◽  
Takeshi Izumi ◽  
Takumi Nishimoto ◽  
Yoshimitsu Shibata ◽  
Kemas Zaini Thosin ◽  
...  
Keyword(s):  
High Temperature ◽  
Diffusion Barrier ◽  
Layer Structure ◽  
Diffusion Coating ◽  
Alloy Layer ◽  
Outward Diffusion ◽  
Hastelloy X ◽  
Alloy Substrate ◽  
Barrier Coating ◽  
Ni Alloy

To suppress interdiffusion between the coating and alloy substrate in addition to ensuring slow oxide growth at very high temperatures advanced coatings were developed, and they were classified into four groups, (1) the diffusion barrier coating with a duplex layer structure, an inner σ−(Re-Cr-Ni) phase as a diffusion barrier and outer Ni aluminides as an aluminum reservoir formed on a Ni based superalloy, Hastelloy X, and Nb-based alloy. (2) the up-hill diffusion coating with a duplex layer structure, an inner TiAl2 + L12 and an outer β-NiAl formed on TiAl intermetallic and Ti-based heat resistant alloys by the Ni-plating followed by high Al-activity pack cementation. (3) the chemical barrier coating with a duplex layer structure, an inner* γ + β + Laves three phases mixture as a chemical diffusion barrier and an outer Al-rich γ-TiAl as an Al reservoir formed by the two step Cr / Al pack process. (4) the self-formed coating with the duplex structure, an inner α-Cr layer as a diffusion barrier and an outer β-NiAl as an Al-reservoir on Ni-(2050)at% Cr alloy changed from the δ-Ni2Al3 coating during oxidation at high temperature. The oxidation properties of the coated alloys were investigated at temperatures between 1173 and 1573K in air for up to 1,000 hrs (10,000 hrs for the up-hill diffusion coating). In the diffusion barrier coating the Re-Cr-Ni alloy layer was stable, existing between the Ni-based superalloy (or Hastelloy X) and Ni aluminides containing 1250at%Al when oxidized at 1423K for up to 1800ks. It was found that the Re-Cr-Ni alloy layer acts as a diffusion barrier for both the inward diffusion of Al and outward diffusion of alloying elements in the alloy substrate. In the chemical barrier coating both the TiAl2 outermost and Al-rich γ-TiAl outer layers maintained high Al contents, forming a protective Al2O3 scale, and it seems that the inner, γ, β, Laves three phase mixture layer suppresses mutual diffusion between the alloy substrate and the outer/outermost layers.

Diffusion barrier development for fiber-reinforced Ni3Al composites

1991 ◽  
Vol 6 (2) ◽  
pp. 355-360 ◽  
Author(s):  
P.C. Brennan ◽  
W.H. Kao ◽  
H.A. Katzman ◽  
J-M. Yang
Keyword(s):  
Diffusion Barrier ◽  
Nickel Aluminide ◽  
Chemical Vapor ◽  
Chemical Compositions ◽  
Ion Microprobe ◽  
Fiber Reinforced ◽  
Reaction Products ◽  
Barrier Coating ◽  
Before And After ◽  
The Matrix

An alumina (Al2O3) diffusion barrier coating to inhibit the interfacial reactions between boron-carbide-coated boron (B4C/B) fibers and a nickel-aluminide (Ni3Al) (IC-221) matrix was investigated. The alumina diffusion barrier was deposited on the B4C/B fibers using chemical vapor deposition. Also, Saphikon single-crystal Al2O3 fibers were used to demonstrate the compatibility between Al2O3 and Ni3Al. The detailed microstructures and chemical compositions of the fibers, coating, and matrix before and after various thermal exposures were analyzed using scanning electron microscopy, energy dispersive x-ray analysis, and ion microprobe mass analysis. The interfacial reaction products present after 6 h at 980 °C were characterized, and Ni was found to be the dominant diffusion species. The alumina diffusion barrier shows promise for effectively inhibiting the deleterious reactions between B4C/B fibers and the Ni3Al matrix. The uncoated B4C/B fibers were consumed by the matrix after fabrication alone, whereas the Al2O3 coated fibers demonstrated resistance to the matrix for 25 h at 880 °C and 6 h at 980 °C. The Saphikon fiber-reinforced Ni3Al composites demonstrated excellent compatibility after 50 h at 1000 °C. Zirconium (Zr)-rich precipitates on the order of 2 μm in diameter formed at the fiber interface after this exposure, but no gross reaction was indicated between the fiber and the matrix.

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