Effect of Alloying Elements Gradient on Solid-State Diffusion Bonding between Aerospace Aluminum Alloys

Three different bonding couples assembled by two commonly used aerospace aluminum alloys were bonded within the temperature range of 460–520 °C under 6 MPa for 60 min in vacuum atmosphere. The interface microstructure and alloying elements distribution of the bonded joints were determined by scanning electron microscope (SEM) and Energy Dispersive Spectroscope (EDS); the bond strength was evaluated by tensile-shear strength test. The results show the bond quality improved effectively as the bonding temperature increased. Compared with the 1420-1420 and 7B04-7B04 bonding couples, the 1420-7B04 couples obtained better interface integrity and higher bond strength, the highest shear strength for 1420-7B04 couple can be as high as 188 MPa when bonded at 520 °C. Special attention was focused on the 1420-7B04 couple, the diffusion coefficient of Mg at the original interface under different temperatures were investigated, the results show the diffusion coefficient increased obviously as the bonding temperature increased. A diffusion affected zone (DAZ) without continuous intermetallic phases formed due to the diffusion of alloying elements across the bonding interface. The combined action of temperature and alloying elements gradient resulted in the increase of alloying elements diffusion fluxes, which in turn promote the bonding quality through the accelerated shrinkage of interfacial voids.

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Sol-Gel Coating Facilitating Si-to-Si Wafer Bonding at Low Temperature

Electronic and Photonic Packaging, Electrical Systems Design and Photonics, and Nanotechnology ◽

10.1115/imece2005-79263 ◽

2005 ◽

Author(s):

J. Wei ◽

S. S. Deng ◽

C. M. Tan

Keyword(s):

Low Temperature ◽

Bond Strength ◽

Wafer Bonding ◽

Intermediate Layer ◽

Bonding Temperature ◽

Sol Gel ◽

Bond Quality ◽

Bubble Generation ◽

High Bond ◽

High Bond Strength

Silicon-to-silicon wafer bonding by sol-gel intermediate layer has been performed using acid-catalyzed tetraethylthosilicate-ethanol-water sol solution. High bond strength near to the fracture strength of bulk silicon is obtained at low temperature, for example 100°C. However, The bond efficiency and bond strength of this intermediate layer bonding sharply decrease when the bonding temperature increases to elevated temperature, such as 300 °C. The degradation of bond quality is found to be related to the decomposition of residual organic species at elevated bonding temperature. The bubble generation and the mechanism of the high bond strength at low temperature are exploited.

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Interfacial Microstructure Investigation of Diffusion Bonded New Ni-Cr-W Superalloy Using Cu Interlayer

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.634-638.1844 ◽

2013 ◽

Vol 634-638 ◽

pp. 1844-1849 ◽

Cited By ~ 1

Author(s):

Rui Hu ◽

Xian Lin Meng ◽

Bin Tang ◽

Chuan Yun Wang ◽

Hong Chao Kou ◽

...

Keyword(s):

Solid State ◽

Bonding Temperature ◽

Interfacial Microstructure ◽

Vacuum Furnace ◽

Solid State Diffusion ◽

Diffusion Behavior ◽

State Diffusion ◽

Different Temperatures ◽

Cu Foil ◽

Cu Interlayer

The solid-state diffusion bonding processes were successfully carried out to join new Ni-Cr-W superalloys at different temperatures (850°C-950°C), under pressures of 20MPa and holding 45min in a vacuum furnace by taking Cu foil as interlayer. The influence of bonding temperature on the microstructural evolution and the diffusion behavior across the joints was investigated in details. Results indicate that the Ni-Cu solid solutions in the interface lead to a sound bonding interface without any void or impurity. As the temperature increases, the reaction layers become thicker due to the decrease of M23C6 precipitation in the grain boundaries and the rise of atoms diffusion capability. Furthermore, hardness measuremental result also reveals that the increased thickness of reaction layers cannot improve the microhardness of bonding interfaces apparently.

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Whitening Dentifrices Effect on Enamel with Orthodontic Braces after Simulated Brushing

European Journal of Dentistry ◽

10.1055/s-0039-3403474 ◽

2020 ◽

Vol 14 (01) ◽

pp. 013-018

Author(s):

Vivian Santos Torres ◽

Max José Pimenta Lima ◽

Heloísa Cristina Valdrighi ◽

Elisângela de Jesus Campos ◽

Milton Santamaria-Jr

Keyword(s):

Shear Strength ◽

Bond Strength ◽

Shear Bond Strength ◽

Color Change ◽

Test Group ◽

Control Group ◽

Test Machine ◽

Color Analysis ◽

Shear Strength Test

Abstract Objective This study aimed to evaluate in vitro the effects of whitening dentifrices on enamel color, the shear bond strength of orthodontic brackets and adhesive remnant index (ARI). Materials and Methods Eighty bovine teeth with brackets were randomly divided into four groups (n = 20): control group (GC)–water, test group 1 (GT1)–Colgate Total 12, test group 2 (GT2)–Curaprox Black Is White, and group test 3 (GT3)–Luminous White. All groups were submitted to brushing, simulating 12 months. The specimens were exposed to spectrophotometer color evaluation and to a shear strength test in a universal test machine using a 300 kN load with a crosshead speed of 0.5 mm/min. The ARI was evaluated with a stereoscopic magnifying glass. Statistical Analysis Nonparametric Kruskal–Wallis and Dunn’s tests were used for the color analysis, and Friedman and Nemenyi tests were used to compare the times in the variable. To compare the shear force between the groups, the data were evaluated by one-way analysis of variance and Tukey’s test, and ARI was analyzed using Fisher’s exact test, always with a significance level of 5%. Results In the color analysis, GT3 presented the greatest progression in whitening effect. GT1 had greater shear strength than GT3 did (p ≤ 0.05). For ARI, the score 1 was predominant in the GC and GT1. The GT2 and GT3 groups had scores of 3. Conclusion The whitening dentifrices promoted significant color change over the 12-month brushing time and may have interfered in the resistance to shear bond strength and ARI.

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Low Temperature Wafer Bonding Process Using Sol-Gel Intermediate Layer

Electronic and Photonic Packaging, Electrical Systems Design and Photonics, and Nanotechnology ◽

10.1115/imece2004-60455 ◽

2004 ◽

Author(s):

S. S. Deng ◽

J. Wei ◽

C. M. Tan ◽

W. B. Yu ◽

S. M. L. Nai ◽

...

Keyword(s):

Low Temperature ◽

Bond Strength ◽

Silicon Wafer ◽

Process Parameters ◽

Wafer Bonding ◽

Intermediate Layer ◽

Bonding Temperature ◽

Sol Gel ◽

Dominant Factor ◽

Bond Quality

Silicon-to-silicon wafer bonding has been successful prepared using sol-gel intermediate layer, which is deposited by spinning acid catalyzed tetraethylthosilicate (TEOS) solution on both two silicon wafer surfaces. To investigate the effects of the process parameters, Draper-Lin small composite design is used, as it requires the minimum runs in the design of experiments. Four process parameters, bonding temperature, solution PH value, solution concentration and solution aging time, have been considered to influence the bond quality, including bond efficiency and bond strength. The bond efficiency is in the range of 40%–90% and bond strength is up to 35 MPa. Statistic analysis shows that the bonding temperature is the dominant factor for the bond quality, while the interaction between temperature and concentration is significant on bond strength. Various characterization techniques, including differential thermal analysis (DTA), atomic force microscopy (AFM), scanning electron microscope (SEM), contact angle measurement and ellipsometry, have been used to study the surface and interface properties. The residual organic species inside the sol-gel coating may be the origin of the significant effect of bonding temperature on the bond efficiency. The interaction effect on bond strength is attributed to the surface hydrophilicity and porosity of sol-gel coating. Higher concentration solution can form lower hydrophilic wafer surface, which results in lower bond strength when bonding temperature is at low level. Whereas, at high bonding temperatures, the increase of porosity of the sol-gel coating prepared by higher sol concentration can absorb more undesired hydrocarbon gas molecules and lead to higher bond strength. The bonding mechanism for the low temperature sol-gel intermediate layer bonding technique is related to the smooth coating surface, porous intermediate layer and water-absent bonding groups.

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Material Shear Strength Assessment of AU/20SN Interconnection for High Temperature Applications

Journal of Mechanics ◽

10.1017/jmech.2018.35 ◽

2018 ◽

Vol 35 (1) ◽

pp. 81-91 ◽

Cited By ~ 1

Author(s):

L. L. Liao ◽

K. N. Chiang

Keyword(s):

Shear Strength ◽

High Temperature ◽

Fracture Morphology ◽

Power Module ◽

Strength Assessment ◽

Shear Strength Test ◽

Treatment Conditions ◽

Temperature Load ◽

Different Temperatures

AbstractWhen a power module is under a continuous electrical load, a temperature effect is induced by the current load in the module configuration. The joint material therefore has long-term temperature and mechanical loadings under supplied power. A long-term temperature load can change the material and mechanical properties, including voiding, cracking, creeping and fracturing. Au/20Sn eutectic alloy, a highly temperature resistant material, is typically used for electric interconnections in high-power modules. The Au/20Sn is converted into AuSn and an Au5Sn intermetallic compound (IMC) by solid liquid inter-diffusion (SLID) bonding to form joints with high melting points. In this study, a test vehicle based on an actual power module was designed and fabricated to investigate and understand the material properties and mechanical behavior of Au/20Sn solder under a temperature load. The joint microstructure exhibited variation under different thermal treatment conditions such as temperature and load durations. The shear strength test was conducted to examine the mechanical strength of the joints under different thermal load conditions. The failure mode of the joint was further determined using fracture morphology after the shear test. Finally, the shear strength of Au/20Sn was identified to investigate the high temperature resistance of joints under different temperatures. The mechanical strengths of joints under different temperature loads are expressions of different mechanical characteristics and can be used to determine reliability at an intended high application temperature.

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Influence of process parameters on bond properties of Al laminated structure produced by ultrasonic consolidation

Rapid Prototyping Journal ◽

10.1108/rpj-08-2014-0094 ◽

2016 ◽

Vol 22 (2) ◽

pp. 435-442 ◽

Cited By ~ 2

Author(s):

Xiao-Hua He ◽

Hui-Ji Shi ◽

Mark Norfolk

Keyword(s):

Aluminum Alloys ◽

Bond Strength ◽

Process Parameters ◽

Failure Modes ◽

Bond Quality ◽

Laminated Structure ◽

Ultrasonic Consolidation ◽

Content Type ◽

Laminated Structures

Purpose The purpose of this paper is to investigate the influence of key parameters on the bond strength and failure modes of laminated structures made of different aluminum alloys (i.e. Al 2024 and Al 7075) via the ultrasonic consolidation (UC) process. Design/methodology/approach The UC is used to fabricate laminated structures with various parameters. The push-pin tests were performed on the specimens of different materials and parameters, and the force and displacement were recorded during the tests. The peak punch force was used to represent the bond quality of the laminated structure, and the curves of force versus displacement were used to study the failure modes of the structures. Findings It is found that the lower normal force, the larger vibration amplitude and the lower travel speed can result in stronger bonding. Three different failure modes are observed in the tests, due to the different relations between the toughness of interface and raw materials. The process parameters have influence on the interface toughness of a laminated structure, which further leads to different failure modes. Originality/value The overall mechanical properties of a laminated structure highly depend on the bond quality between laminated layers. The push-pin test can easily and effectively evaluate the bond quality of the laminated structure. This paper not only focuses on the bond strength evaluation, but also analyzes the different failure modes of laminated structures made of different aluminum alloys, which can give an opportunity to optimize the parameters for different materials.

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The Preparation of Aluminum-Bronze/Steel Duplex Metal by Loose Sintering

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.311-313.160 ◽

2011 ◽

Vol 311-313 ◽

pp. 160-164 ◽

Cited By ~ 3

Author(s):

Qi Yang ◽

Shun Huang ◽

Jin Tian Chen ◽

Guang Zhi He ◽

Guo Zheng Yan

Keyword(s):

Shear Strength ◽

Bond Strength ◽

Relative Density ◽

Density Measurement ◽

Aluminum Bronze ◽

Shear Strength Test ◽

Bronze Powder ◽

Sintered Aluminum ◽

Compression Shear Strength ◽

Electronic Microscope

Aluminum-bronze/steel duplex metal has been prepared by aluminum-bronze powder whose compact oxide film was removed by dilute HCl solution before sintering. Scanning electronic microscope (SEM), energy spectrum analysis (EDS), density measurement and compression shear strength test were used to investigate the structure, composition, relative density and bond strength of aluminum-bronze/steel duplex metal. The results show: liquid phase could wet the aluminum-bronze powder washed by acid, improve sintering activity of the powder and increase bond strength of aluminum-bronze/steel interface. The relative density of sintered aluminum-bronze is 99.6%, and shear strength of aluminum-bronze/steel interface is 132.6MPa.

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Effect of joining temperature on Al2024/Ag/Ti-6Al-4V joints during transient liquid phase bonding

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-1110509 ◽

2020 ◽

Vol 111 (5) ◽

pp. 424-431

Author(s):

Hamid Naeimian ◽

Mohammad Ammar Mofid

Keyword(s):

Mechanical Properties ◽

Shear Strength ◽

Bonding Temperature ◽

Transient Liquid Phase ◽

Silver Foil ◽

X Ray Diffraction ◽

X Ray ◽

Diffusion Bonds ◽

State Diffusion ◽

Distribution Of Elements

Abstract The objective of this study is to investigate the effect of bonding temperature on the microstructure and mechanical properties of Al2024 and Ti-6Al-4V diffusion bonds using a 30 μm pure silver foil as interlayer. Using optical microscopy, scanning electron microscopy, line scan and X-ray diffraction, the interfaces of joints were evaluated. The mechanical properties of joints were measured using Vickers micro-hardness and shear strength. At the bonding temperature of 570°C joints contained a non-uniform distribution of elements and various intermetallic phases. With increasing bonding temperature, an uninterrupted microstructure is achieved. According to the results, liquid eutectic formed between Ag interlayer and Al2024, while solid-state diffusion occurs between the Ag interlayer and Ti-6Al-4V. The increase in bonding temperature from 570 to 580 °C resulted in higher shear strength, from 71 MPa to 121 MPa.

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Transient Liquid Diffusion Bonding of AISI304 Stainless Steel with a Nickel Base Interlayer

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.380.48 ◽

2017 ◽

Vol 380 ◽

pp. 48-54 ◽

Cited By ~ 3

Author(s):

R. Jamshidi Lamjiri ◽

A. Ekrami

Keyword(s):

Stainless Steel ◽

Shear Strength ◽

Bonding Temperature ◽

Alloying Elements ◽

Joint Region ◽

Joint Shear Strength ◽

Homogenization Time ◽

Parent Alloy ◽

Electron Microscopes ◽

Nickel Base

AISI304 stainless steel was bonded by a nickel base interlayer, using a TLP bonding method at 1150 °C with different holding times. The microstructure of the joint region was studied by optical and scanning electron microscopes. The results showed that 20 minutes holding time is sufficient for complete isothermal solidification. At the bonding times of 4, 10, 15 minutes, a eutectic structure was formed at the joint region. The distribution of alloying elements within the joint region and diffusion affected zone were detected using EDS. The results showed that the eutectic microstructure consists of Fe and Cr borides and the isothermal solidified zone consists of solid solution of Fe and Ni at the bonding temperature. Samples with complete isothermal solidified joint were homogenized at 950°C for different times from 30 to 360 minutes to study the distribution of alloying elements between joint region and parent alloy. The results showed more uniform distribution of alloying elements with increasing the homogenization time due to the diffusion of alloying elements between the joint region and the parent alloys. Microhardness and shear strength of joined samples were measured and compared to that of the parent alloy at the same heat treatment condition. The joint shear strength of TLP bonded samples was about 82% that of the parent alloy at the homogenization time of 180 minutes.

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