Investigation of bonding strength and sealing behavior of aluminum/stainless steel bonded at room temperature (original) (raw)
Related papers
Transient Liquid Phase Bonding of Al-6063 to Steel Alloy UNS S32304
Transient liquid phase (TLP) bonding of Al-6063 and UNS S32304 was performed using copper foil as an interlayer between the base metals. A compression load was applied normal to the specimens. Metallurgical examination of the produced joints showed three distinct regions including a reaction zone, diffusion affected zone and the base metals. The diffusion of copper into aluminum resulted in an Al-Cu eutectic structure. However, the oxide layer on the aluminum surface controlled the dissolution behavior of copper and the extent of its wettability with the base metals. Although voids and intermetallic compounds were detected at the interfaces of the processed joints, a defect free joint was produced at…
2021
LNLS has been commissioning Sirius, a 4th-generation synchrotron light source. The commissioning of the beamlines has been mainly done by using planar undulator, which uses in-house built aluminum vacuum chambers with ultra-high vacuum tight bimetallic flanges. In order to manufacture these flanges, diffusion bonded joints of AA6061 aluminum alloy to AISI 316LN stainless steel were developed. Diffusion bonding was carried out at 400-500°C for 45-60 min, applying a load of 9.8MPa in a vacuum furnace. Also, the surface preparation for Al and SS was investigated. SEM observation revealed that an 1-3 µm reaction layer was formed at the AA6061/Ni-plated interface. The intermetallic compound Al3Ni was identified in the reaction layer. The obtained Al/SS joints showed mean ultimate strength of 84 MPa, with the fracture occurring in the Al/reaction layer interface. Bake-out cycles followed by leak tests were carried out to validate the process and approve their use on the planar undulator v...
International Journal of Hydrogen Energy, 2015
Fabrication of a bimetallic joint to facilitate a material transition from a 6061-T651 aluminum pressure vessel liner to stainless steel tubing in cryogenic pressure vessels is explored using three different dissimilar metal interlayers with an explosive welding (EXW) process. Due to difficulties in directly EXW joining aluminum (Al) 6061 to 304 stainless steel, interlayers are used to prevent interaction of the aluminum and stainless steel, thus minimizing brittle intermetallic phase formation. Titanium (Ti) copper (Cu) and tantalum (Ta) were selected as the dissimilar metal interlayer materials; each having advantages and disadvantages. Titanium is a commonly used interlayer for this joint, but can microcrack during EXW if the bonding parameters are not correct. Copper has the advantage that it is compatible with hydrogen, but is also known to form brittle intermetallics with aluminum. Tantalum is ductile and bonds well to both Al and stainless steel, and is a high temperature metal that does well to prevent interdiffusion and intermetallic phase formation. However Ta is the most expensive metal of the three. Results of the characterization of the three interlayer bonds showed that Ti produced the highest strength joints, Ta produced the most ductile joints, and Cu produced a joint that failed with low ductility at the Al/Cu interface. Based on these results, the Cu-interlayer joint is not recommended for this application, while the Ti and Ta interlayer bonds both appear to have sufficient strength and ductility for the intended use.
Al-Ge Diffusion Bonding for Hermetic Sealing Application
Journal of Electronic Materials, 2015
The high-temperature requirement of Al-Ge eutectic bonding stands as a major obstacle in the wider acceptance for the hermetic sealing application among the micro-electro mechanical systems (MEMS) packaging industry, in particular for temperature sensitive devices. It has been demonstrated that the reduction in bonding temperature is feasible without compromising the hermeticity. The change in the mode of bonding from eutectic to solid-state diffusion did not have a dramatic impact on the bonding quality. However, this resulted in substantial increase in the bonding time. Shear strength too deteriorated as a result of the decrease in the thickness of the reaction interface. However, the shear strength still complied with the Military Standards (MIL). It has been confirmed that the hermetic seal could still be achieved without any solidification occurring at the interface. This is feasible since the inter-diffusion coefficients of Al in (Ge) phase and Ge in (Al) phase are closer and are comparable to diffusion between solidsolution phases of identical metals like Au-Au, Cu-Cu, Si-Si bonding, which are generally used for such hermetic sealing application. Appropriate stacking mechanism for Al/Ge diffusion bonding is identified to overcome the limitations with respect to surface topography.
Characterization of aluminium single-lap joints for high temperature applications
Materials Science Forum, 2013
In this study, an experimental investigation into the shear strength behaviour of aluminium alloy single-lap adhesive joints was carried out in order to understand the effect of temperature on the strength of adhesively bonding joints. Single lap joints (SLJs) were fabricated and tested at RT and high temperatures (100ºC, 125ºC, 150ºC, 175ºC and 200ºC). Results showed that the failure loads of the single-lap joint test specimens vary with temperature and this needs to be considered in any design procedure. It is shown that, although the tensile stress decreased with temperature, the lap-shear strength of the adhesive increased with increasing of temperature up to the glass transition of the adhesive (T g ) and decreased for tests above the T g .
Environmental Stress Testing of Wafer-Level Al-Al Thermocompression Bonds: Strength and Hermeticity
ECS Journal of Solid State Science and Technology, 2015
Hermeticity, reliability and strength of Al-Al thermocompression bonds realized by applying different bonding parameters have been investigated. Laminates of diameter 150 mm were realized by bonding wafers containing membrane structures to wafers with patterned bonding frames. The laminates were bonded applying a bond force of 36 or 60 kN at temperatures ranging from 300 to 400 • C for 15, 30 or 60 minutes. The hermetic properties were estimated by membrane deflection measurements with white-light interferometry after bonding. Reliability was tested by exposing the laminates to a steady-state life test, a thermal shock test, and a moisture resistance test. Bond strength was measured by shear test and pull tests. Laminates bonded applying a bond force of 60 kN at temperatures of 350 or 400 • C resulted in hermetic bonds. No significant change in membrane deflection was observed after the steady-state life test or the thermal shock test. However, a gross leakage was observed in 1-11% of the dies after exposure to the moisture resistance test. The maximum leakage rate (MLR) estimated from membrane deflection measurements was below 10 −11 mbar · l · s −1 for all laminates. The measured average bond strength of dies from selected laminates ranged from 28 to 190 MPa.
Pipe-to-pipe friction welding of dissimilar Al-SS joints for cryogenic applications
Journal of the Brazilian Society of Mechanical Sciences and Engineering
In the present investigation, dissimilar materials such as AA6063 and SS304L having pipe dimensions of 60.33 mm outer diameter and 3.9 mm wall thickness were friction-welded with different conditions of process parameters. Nondestructive tests such as radiography test (RT) and liquid penetration test (LPT) were carried out on the welded pipes in order to qualify weld joint. Thermal shock test and helium leak tests were performed on the successful welded samples in order to check its ability to work with cryogenic application. The results revealed that the pipe-to-pipe configuration of dissimilar Al–SS joints was produced successfully by friction welding using continuous drive. There were no defects presented in the joint area as revealed by RT and LPT. Thermal shock test and helium leak tests have also confirmed the soundness of joints. Higher deformation of Al base material results in the huge flash formation of Al that results in the sleeve formation of Al pipe on SS pipe. The hel...
Materials, 2024
Adhesive bonding has proven to be a reliable method of joining materials, and the development of new adhesives has made it possible to use bonding in a variety of applications. This article addresses the challenges of bonding metals such as the aluminum alloy EN AW-5754 and the stainless steel X5CrNi18-10. In this study, the effects of laser cleaning and texturing on the surface properties and strength of two bonded joints were investigated and compared with mechanical preparation (hand sanding with Scotch-Brite and P180 sandpaper). The bonded joints were tested with three different epoxy adhesives. During the tests, the adhesion properties of the bonded surface were determined by measuring the contact angle and assessing the wettability, the surface roughness parameters for the different surface preparations, and the mechanical properties (tensile lapshear strength). Based on the strength test results, it was found that bonded joints made of stainless steel had 16% to 40% higher strength than aluminum alloys when using the same adhesive and surface preparation. Laser cleaning resulted in maximum shear strength of the aluminum alloy bond, while the most suitable surface preparation for both materials was preparation with P180 sandpaper for all adhesives.