scholarly journals Microstructure and Strength of γ-TiAl Alloy/Inconel 718 Brazed Joints

2012 ◽  
Vol 730-732 ◽  
pp. 835-840 ◽  
Author(s):  
Elsa W. Sequeiros ◽  
Anibal Guedes ◽  
Ana Maria Pires Pinto ◽  
Manuel F. Vieira ◽  
Filomena Viana
Keyword(s):  
Inconel 718 ◽  
Tial Alloy ◽  
Electron Backscatter Diffraction ◽  
Braze Alloy ◽  
Base Material ◽  
Industrial Applications ◽  
Processing Conditions ◽  
Average Shear Strength ◽  
Average Shear ◽  
Brazed Joints

Intermetallics and superalloys brazing development is a current topic owing the extending use of these alloys in industrial applications. In this work a γ-TiAl alloy was joined to Inconel 718 by active metal brazing, using Incusil-ABA as filler. Joining was performed at 730 °C, 830 °C and 930 °C, with a 10 min dwelling time. The interfaces were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and Electron Backscatter Diffraction (EBSD). For all processing conditions, the reaction between the base materials and the braze alloy produced multilayered interfaces. For all processing temperatures tested (Ag), (Cu), AlNi2Ti and AlCu2Ti were identified at the interface. Raising the brazing temperature increased the thickness of the interface and coarsened its microstructure. The increase of the extension of the interface was essentially due to the growth of the reaction layers formed near each base material, which were found to be mainly composed of intermetallic compounds. The mechanical behavior of the joints, at room temperature, was assessed by microhardness and shear tests. For all processing conditions the hardness decreases from periphery towards the Ag-rich centre of the joints. Brazing at 730 °C for 10 min produced the joints with the highest average shear strength (228±83 MPa). SEM and EDS analysis of the fracture surfaces revealed that fracture of joints always occurred across the interface, preferentially through the hard layer, essentially composed of AlNi2Ti, resulting from the reaction between Inconel 718 and the braze alloy.

Vacuum Brazing Incoloy 800 Using the Copper Foil

2015 ◽  
Vol 1101 ◽  
pp. 99-103
Author(s):  
Cheng Yen Wang ◽  
Ren Kae Shiue
Keyword(s):  
Shear Strength ◽  
Copper Foil ◽  
Vacuum Furnace ◽  
Vacuum Brazing ◽  
Average Shear Strength ◽  
Average Shear ◽  
Incoloy 800 ◽  
Brazed Joints ◽  
Brazed Joint ◽  
Time Average

The purpose of this research is focused on vacuum furnace brazing Incoloy 800 (IN-800) using the copper filler foil. Microstructural evolution and shear strength of brazed joints for various brazing conditions has been evaluated in the experiment. The Cu-rich matrix dominates entire brazed joint. The width of Cu-rich matrix is decreased with increasing the brazing temperature and/or time. Average shear strength of the joint is approximately 215 MPa. Dimple dominated fracture is widely observed for the specimen brazed below 1160oC. However, cleavage dominated fracture is found for the specimen brazed at 1200oC. It is advised that copper brazing IN-800 alloy should be confined below 1160oC.

scholarly journals Infrared Brazing of CoCrFeMnNi Equiatomic High Entropy Alloy Using Nickel-Based Braze Alloys

Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 283 ◽  
Author(s):  
Chieh Lin ◽  
Ren-Kae Shiue ◽  
Shyi-Kaan Wu ◽  
Huai-Li Huang
Keyword(s):  
Shear Strength ◽  
Grain Boundary ◽  
High Entropy Alloy ◽  
Solidification Shrinkage ◽  
Vacuum Brazing ◽  
High Entropy ◽  
Average Shear Strength ◽  
Average Shear ◽  
Brazed Joints ◽  
Liquidus Temperatures

Infrared vacuum brazing of CoCrFeMnNi high entropy alloy (HEA) using BNi-2 and MBF601 fillers has been investigated. Both brazes show poor wettability at temperatures only 20 °C above their liquidus temperatures. However, the wettability of BNi-2 and MBF601 fillers on CoCrFeMnNi HEA is greatly improved with increasing the test temperatures, 50 °C above their liquidus temperatures. The BNi-2 brazed joints are dominated by Ni-rich matrix with huge CrB and a few tiny boride precipitates. Average shear strengths of joints increase with increasing brazing temperature and/or time, and fracture location changes from blocky CrB in the brazed zone to grain boundary boride in the substrate. The MBF601 brazed joints are composed of CoCrFeMnNi-based matrix, particles of B/Co/Cr/Fe/Mn/Ni/P compounds, and some phosphides form along the grain boundaries of the substrate. The specimen brazed with MBF601 filler foil at 1050 °C for 600 s has the highest average shear strength of 321 MPa, while that brazed at 1080 °C for 600 s has a lower average shear strength of 271 MPa due to the presence of solidification shrinkage voids.

Assessing the Influence of Heat Treatments on γ-TiAl Joints

2006 ◽  
Vol 514-516 ◽  
pp. 1333-1337 ◽  
Author(s):  
Anibal Guedes ◽  
Ana Maria Pires Pinto ◽  
Manuel F. Vieira ◽  
Filomena Viana
Keyword(s):  
Titanium Aluminide ◽  
Tial Alloy ◽  
Braze Alloy ◽  
Heat Treating ◽  
Heat Treatments ◽  
Interfacial Zone ◽  
Alloy Foil ◽  
Heat Treated ◽  
Titanium Aluminide Alloy ◽  
Brazed Joints

The heat treatment of γ-TiAl alloy (Ti-47Al-2Cr-2Nb (at.%)) diffusion brazed joints was investigated. Joining was performed using a Ti/Ni/Ti clad-laminated braze alloy foil at 1050 and 1150°C with a dwell time of 10 minutes. The joints were subsequently heat treated at 1250 and 1350°C for 240 and 30 minutes, respectively. The microstructure and the chemical composition of the interfaces were analysed by scanning electron microscopy (SEM) and by energy dispersive X-ray spectroscopy (EDS), respectively. Microhardness tests performed across the interface were used to roughly predict the mechanical behaviour of the as-diffusion brazed and of the heat treated joints. Diffusion brazing produced interfaces with two distinct layers essentially composed of α2-Ti3Al and of TiNiAl; γ-TiAl was also detected for joining at 1150°C. After heat treating, the as-diffusion brazed microstructure of the interface was completely replaced by a mixture essentially composed of γ-TiAl and α2–Ti3Al single phase grains and of (α2 + γ) lamellar grains. Microhardness tests showed that the hardness of the as-diffusion brazed interfaces, which ranges from 567 to 844 HV (15 gf), is significantly higher than that of the titanium aluminide alloy (272 HV). All post-joining heat treatments lowered substantially the hardness of the interface, as the hardness of the main phases detected at the interfacial zone after heat treating the joints is comprised between 296 and 414 HV.

scholarly journals Microstructure and Physical Properties of Alloy Brazed with Filler by Mapping Scanning Analysis and Wettability Test

2021 ◽  
Vol 2083 (2) ◽  
pp. 022086
Author(s):  
Xiupeng Li ◽  
Yunyue Li ◽  
Sujuan Zhong ◽  
Yuanxun Shen ◽  
Weimin Long ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Shear Strength ◽  
Filler Metal ◽  
Solidus Temperature ◽  
Spreading Effect ◽  
Average Shear Strength ◽  
Average Shear ◽  
Brazed Joints ◽  
Brazed Joint ◽  
New Type

Abstract In this paper, a new type of AlSiMgCuNiAg filler metal was developed. The solidus temperature of the filler metal is 509.1°C and the liquidus temperature is 531.3°C. The filler metal has a good wetting and spreading effect on the surface of 6061 aluminum alloy. The CuAl2 phase in the brazing seam was greatly aggregated after brazed, while the CuAl2 phase was reduced and Mg2Si strengthening phase was formed when the brazed joints with heat treatment. The average shear strength of the brazed joint without heat treatment was 47.1MPa, and the average shear strength of the brazed joint with heat treatment reached to 108.7Mpa. The strength of the brazed joint with heat treatment was increased by about 131% relative to the strength of the brazed joint without heat treatment.

scholarly journals Micro-Brazing of Stainless Steel Using Ni-P Alloy Plating

2019 ◽  
Vol 9 (6) ◽  
pp. 1094
Author(s):  
Shubin Liu ◽  
Ikuo Shohji ◽  
Makoto Iioka ◽  
Anna Hashimoto ◽  
Junichiro Hirohashi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Shear Strength ◽  
Solid Solutions ◽  
Joint Strength ◽  
Filler Metal ◽  
Average Shear Strength ◽  
Average Shear ◽  
Brazed Joints ◽  
Brazed Joint ◽  
Alloy Plating

A Ni-P plated layer of 20 μm thickness containing 11 wt.% P was formed on the surface of a stainless steel (SUS304) plate by electroplating. The microstructure and joint strength of the brazed joint with the electroplated Ni-11P layer were investigated. The results indicated that the filler metal was homogeneously distributed between the SUS304 plates and no voids or flaws formed in the brazed filler zone. Fe-Ni-Cr solid solutions were formed at the brazed interface. Moreover, P was mainly concentrated in such brazed filler zone to form P-containing phases. The average shear strength of the brazed joints was determined to be 47.3 MPa. The results demonstrated that the brazing of SUS304 plates using the electroplated Ni-11P layer as the filler metal was successfully realized.

scholarly journals Vacuum Brazing Ti–15–3 with a TiNiNb Braze Alloy

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1085 ◽  
Author(s):  
Kao ◽  
Tsay ◽  
Wang ◽  
Shiue
Keyword(s):  
Intermetallic Compound ◽  
Braze Alloy ◽  
Intermetallic Phases ◽  
Brazing Fillers ◽  
Rich Phase ◽  
Ductile Dimple ◽  
Vacuum Brazing ◽  
Average Shear Strength ◽  
Average Shear ◽  
Brazed Joint

Among all types of brazing fillers, Ti-based fillers show satisfactory joint strengths in brazing titanium alloys. However, the major concern in using such fillers is the formation of Cu/Ni/Ti intermetallic compound(s) in the joint. In this study, a Ti–15–3 alloy was vacuum brazed with a clad Ti–35Ni–25Nb foil. The brazed zone consisted of a Ti2Ni intermetallic compound in a (β-Ti,Nb)-rich matrix for specimen brazing at 1000 °C/600 s. Raising brazing temperature and time resulted in the Ti2Ni dissolving into the (β-Ti,Nb)-rich matrix. For the specimen brazing at 1100 °C/600s, Ti2Ni could only be observed at the grain boundaries of the (β-Ti,Nb)-rich matrix. After further raising it to 1200 °C/600 s, the Ti2Ni intermetallic compound was all dissolved into the (β-Ti,Nb)-rich phase. The average shear strength was significantly raised from 140 (1000 °C/600 s) to 620 MPa (1100 °C/3600 s). Crack initiation/propagation in the brittle Ti2Ni compound with the cleavage fractograph were changed into the Ti–15–3 base metal with a ductile dimple fractograph. The advantage of using Nb in the TiNiNb filler foil was its ability to stabilize β-Ti, and most of the Ni in the braze alloy was dissolved into the β-Ti matrix. The brazed joint could be free of any intermetallic phases with a proper brazing cycle applied, and the joint was suitable for a few harsh applications, e.g., repeated stresses and impact loadings.

scholarly journals Characterization of Soldering Alloy Type Bi-Ag-Ti and the Study of Ultrasonic Soldering of Silicon and Copper

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 624
Author(s):  
Roman Kolenak ◽  
Igor Kostolny ◽  
Jaromir Drapala ◽  
Paulina Babincova ◽  
Peter Gogola
Keyword(s):  
Eutectic Reaction ◽  
Research Work ◽  
Copper Substrate ◽  
Liquid Bismuth ◽  
Alloy Type ◽  
Average Shear Strength ◽  
Average Shear ◽  
The Matrix ◽  
Solder Microstructure ◽  
Ultrasonic Soldering

The aim of the research work was to characterize the soldering alloy type Bi-Ag-Ti and to study the direct soldering of silicon and copper. Bi11Ag1.5Ti solder has a broad melting interval. Its scope depends mainly on the content of silver and titanium. The solder begins to melt at the temperature of 262.5 ∘C and full melting is completed at 405 ∘C. The solder microstructure consists of a bismuth matrix with local eutectics. The silver crystals and titanium phases as BiTi2 and Bi9Ti8 are segregated in the matrix. The average tensile strength of the solder varies around 42 MPa. The bond with silicon is formed due to interaction of active titanium with the silicon surface at the formation of a reaction layer, composed of a new product, TiSi2. In the boundary of the Cu/solder an interaction between the liquid bismuth solder and the copper substrate occurs, supported by the eutectic reaction. The mutual solubility between the liquid bismuth solder is very limited, on both the Bi and the Cu side. The average shear strength in the case of a combined joint of Si/Cu fabricated with Bi11Ag1.5Ti solder is 43 MPa.

Sub-100 μm SnAg Solder Bumping Technology and the Bump Reliability

2009 ◽  
Vol 131 (1) ◽  
Author(s):  
Xiaoqin Lin ◽  
Le Luo
Keyword(s):  
Cu6sn5 Phase ◽  
X Ray ◽  
Solder Bumps ◽  
Average Shear Strength ◽  
Average Shear ◽  
Snag Solder ◽  
Packaging Industry ◽  
Negative Impacts ◽  
Free Solder ◽  
Electroplating Process

Lead-free solder bumping and its related interconnection and reliability are becoming one of the important issues in today’s electronic packaging industry. In this paper, alloy electroplating was used as SnAg solder bumping process. Multiple reflow was preformed on as-plated solder bumps. Scanning electron microscopy and energy dispersive X-ray analysis were used to investigate the intermetallic compound and microvoids of cross-sectioned solder bump. Shear test was used to evaluate the reliabilities of the SnAg bumps. The 13×13 area-array Sn/3.0Ag solder bumps of 70 μm in height and 90 μm in diameter were fabricated with a smooth and shiny surface and with a uniform distribution of Ag. During multireflow, the scalloped Cu6Sn5 phase grows by a ripening process. Volume shrinkage was the main reason for the formation of microvoids during multireflow. The average shear strength of solder bumps on TiW/Cu under bump metallurgy (UBM) increased with reflow times. The electroplating process is suitable for mass production of well-controlled geometry and uniformity of SnAg solder bumps. Microvoids have trivial negative impacts on the solder bonds. The combination of TiW/Cu UBM and SnAg solder is reliable.

Superplastic Behavior and Microstructure of Titanium (Ti-6Al-4V) Friction Stir Welds Made under a Variety of Processing Conditions

2010 ◽  
Vol 433 ◽  
pp. 169-176 ◽  
Author(s):  
Paul Edwards ◽  
Mamidala Ramulu ◽  
Daniel G. Sanders
Keyword(s):  
Friction Stir Welding ◽  
Base Material ◽  
Superplastic Forming ◽  
Spindle Speed ◽  
Processing Conditions ◽  
Superplastic Behavior ◽  
Friction Stir ◽  
Fine Grained ◽  
Weld Parameters

Friction Stir Welding of Ti-6Al-4V was performed on 5 mm thickness plate in order to assess the affect of welding conditions on the resulting microstructure and superplastic forming behavior of the joints. A variety of welding conditions were tested and all welds were subsequently Superplastically formed. It was found that the weld parameters do influence the microstructure and degree of superplastic performance of the joints. Spindle speed was found to have the most dominant affect on the resulting microstructure and superplastic forming behavior. Low spindle speed welds lead to fine grained microstructures and highly superplastic welds, relative to the base material, while high spindle speed welds larger grained microstructures and less superplastic welds.

Shear strength and cracking behavior of Cr coatings on zirconium alloy fuel claddings at different strain rates

2021 ◽  
pp. 2150194
Author(s):  
Xiulin Yan ◽  
Ruiqian Zhang ◽  
Yan Liu ◽  
Yunhua Zhang ◽  
Hui Chen
Keyword(s):  
Shear Strength ◽  
Interfacial Shear Strength ◽  
Strain Rates ◽  
Cracking Behavior ◽  
Shear Lag Model ◽  
Loading Direction ◽  
Average Shear Strength ◽  
Average Shear ◽  
Lag Model ◽  
Cr Coating

Cr coating on Zr-based fuel tubes is a potential approach for the development of accident tolerant fuels (ATF). To settle the cracking behavior and quantitative evaluation of shear strength of Cr coating under different loading conditions, the average shear strength between Cr coating and zircaloy substrate has been estimated using a modified shear-lag model in this paper. Its key parameters are determined experimentally, and the tensile method has been used to research the cracking behavior of Cr coating under different strain rates. The results show that with the increase of strain rate, the interfacial shear strength increases because of the decrease of cracking spacing, while the shear strength changes erratically with the coating thickness increases. Furthermore, abundant two unequal-crack-spacings and few two equal-crack-spacings are observed which are perpendicular to the loading direction.

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