scholarly journals Interfacial Behavior and Shear Strength of Al-25Si-4Cu-1Mg Joints by Transient Liquid Phase Bonding with Cu as Interlayer

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1637
Author(s):  
Kai Qi ◽  
Guo Xu ◽  
Fengjiang Wang

Spray-formed hypereutectic Al-Si-Cu-Mg alloy is the candidate for automotive and aerospace industries due to its superior wear resistance, lower thermal expansion coefficient and density, and higher thermal conductivity. This paper aims to investigate the bonding properties of hypereutectic Al-25Si-4Cu-1Mg alloys using the transient liquid phase (TLP) method with Cu as an interlayer. To obtain the suitable bonding parameters, the interfacial microstructure and shear strength of Al-25Si-4Cu-1Mg joints were investigated with the effect of different bonding temperatures and holding times. The results showed that TLP bonding between Al-Si-Mg-Cu alloy was mainly realized by large amounts of Al2Cu intermetallic compounds (IMCs), primary Si and α-Al phases. With the brazing temperature increasing, the width of the brazing seam gradually increased, and the voids began to be produced. With the holding time increasing, θ-Al2Cu phases approached into the base metal and Si particles in the brazing seam were obviously coarsened. With the formation of θ-Al2Cu phases into the base metal, more Si particles were segregated at the interface between brazing seam and base metal, and the shear test confirmed that it was the weakest bonding location. Finally, the effect of bonding parameters on the joint strength indicated that the joint brazed at 540 °C for 7.5 min presented the best shear performance with the shear strength reaching 75 MPa because the size of Si particles in the brazing seam was closest to the size of Si particles in base metal under this parameter.

2015 ◽  
Vol 2015 (1) ◽  
pp. 000449-000452 ◽  
Author(s):  
Xiangdong Liu ◽  
Hiroshi Nishikawa

We develop a transient liquid phase sinter (TLPS) bonding using Sn-coated Cu micro-sized particles. With this bonding process, a thermally stable joint comprising Cu3Sn phase and a dispersion of ductile Cu particles can be obtained. The particle paste, which contained Cu particles with a thin Sn coating and terpineol, was used to join Cu substrates. The setup was bonded at 300 °C for 30s under an applied pressure of 10 MPa using a thermo-compression bonding system under a formic acid gas atmosphere for reducing the oxide layer on the Sn coating and the Cu substrate. After bonding, the TLPS joint showed a thermally stable microstructure with a good shear strength, which was fully consisted of Cu3Sn intermetallic compounds matrix and embedded ductile Cu particles. The kinetics of the microstructure transformation and high temperature reliability of the TLPS joint were investigated. After 300 °C isothermal aging for 200h, the shear strength and microstructure of the TLPS joints showed almost unchanged. The results demonstrate that joint with high-melting-point obtained by the TLPS bonding using Sn-coated Cu particle paste has the potential to fulfill the requirement of high temperature electronic packaging.


2019 ◽  
Vol 944 ◽  
pp. 593-599
Author(s):  
Ben Sheng Huang ◽  
Xiong Wen ◽  
Xing Zhao ◽  
Guang Wen Li

Aluminum foams/aluminum plate was transient liquid phase diffusion bonded with Cu/Al/Cu composite interlayer, then the investigation on joint microstructure, element diffusion and joint strength was conducted at 565°C. The results showed that, there was a significant grain boundary penetration phenomenon near the interface and it was more seriously at the side of aluminum foams. The XRD results showed indicated that the main phases near the interface were α-Al, CuAl2, AlCu, Al4Cu9, Al2O3. By EDS line scanning, it indicated that the diffusion behavior of elements was different at three regions, compared with the edge region, the interface of the central region was better and the depth of element diffusion is larger, at the pore region, the liquefaction of interlayer was not successfully and the morphology was lamellar. Mechanical properties test showed that the largest shear strength of joint was 4.61 MPa when the duration was 40 min. Key words: Aluminum foams; transient liquid phase bonding; microstructure; element diffusion; shear strength


2006 ◽  
Vol 45 ◽  
pp. 1588-1593
Author(s):  
Mathieu Brochu ◽  
Fabian Edelmann ◽  
Robin Valin ◽  
Robin A.L. Drew

Transient Liquid Phase Bonding (TLPB) is a joining process that uses liquid as medium for the establishment of an interface between two faying surfaces. In TLPB, as opposed to brazing process, the careful selection of the interlayer materials and the use of a prolonged heat treatment, allows for isothermal solidification and results in interfaces possessing potential service temperature higher than the joining temperature itself. Such a process is attractive for joining ceramics to metals and composites. In this presentation, the applicability of TLPB for various systems: Si3N4/FA-129 iron aluminide alloy, Al2O3/Al2O3, Al-Al2O3/Al-Al2O3, Al-Al2O3/Al-SiC and Al-Al2O3/Al. Results on the interface formation, interfacial microstructure and mechanical properties will be presented. A comparison of the TLPB joint properties with traditional joining for similar systems will be illustrated.


2005 ◽  
Vol 475-479 ◽  
pp. 639-642
Author(s):  
Sung Wook Kim ◽  
Chang Hee Lee

This study was carried out to investigate the effect of heating rate on the phase transition between additive base metal powder and liquid insert metal during transient liquid phase (TLP) diffusion bonding of Ni-based superalloy GTD-111. Heating rates studied were 10, 1, 0.5 and 0.1°Cs-1 in high vacuum conditions (3×10-5 torr) by means of a high frequency induction furnace. When heated at lower than 0.5°Cs-1, the transition of dissolution to solidification occurred during heating. In the case of very slow heating, the dissolution quickly finished at a lower temperature, and solidification soon started. The separated grains of additive base metal powders supplied the lager interface area for the diffusion of boron. Solidification transition temperatures of liquid phase were affected by the increase of diffusion interface and of duration time during slow heating. A minimum heating rate required to heat insert materials to a normal TLP isothermal bonding temperature of GTD-111 (≈1150°C) without a dissolution-solidification transition during heating should be higher than 1°Cs-1.


2013 ◽  
Vol 631-632 ◽  
pp. 44-49
Author(s):  
Yao Chu ◽  
Shi Hang Jiang ◽  
Wei Jian Fan ◽  
Zhao Yang Jin ◽  
Du Xiong Wang

Transient liquid-phase(TLP) bonding of SiC particle reinforced aluminum matrix composite(SiCp/Al MMCs) ,using Cu film, Cu foil, Ni foil and Cu/Ni/Cu multilayer foil interlayer, was investigated. The effect of surface status, interlayer species and bolding time on bonding microstructure and properties were also estimated by metallographic microscope, scanning electron microscopy (SEM), X ray diffraction and tensile testing machine. The results show that adding holding time can improve shear strength of joint. Better strength of joint can be obtained due to without the effect of oxide with Cu film as interlayer, when bonding at 853K for 120min under 2MPa pressure, the shear strength of bonded joints can obtain 169.1MPa, about 81.7 percentage of the strength of base material. Best strength of joint can be obtained with Cu/Ni/Cu multilayer foil as interlayer, when bonding at 923K for 120min under 2MPa pressure, the of bonded joints can obtain 189.6MPa, about 84.6 percentage of the strength of base material.


2013 ◽  
Vol 2013 (1) ◽  
pp. 000951-000956 ◽  
Author(s):  
Hannes Greve ◽  
F. Patrick McCluskey

Low Temperature Transient Liquid Phase Sintering (LT-TLPS) enables the formation of joints robust to high temperatures at low process temperatures. TLPS systems consist of one or more low temperature constituents (i.e. Sn) and one or more high temperature constituents (i.e. Cu). The sinter joints are formed by intermetallic compound formation between these constituents. In this paper a paste based LT-TLPS approach is demonstrated. The organic binders and fluxes used to mix the pastes prevent the metal particles from oxidation and facilitate a vacuum-free process in air without the need of a reducing atmosphere. Pastes based on the Cu-Sn system have been developed enabling a completely pressure-less process. Furthermore sinter pastes for LT-TLPS at low pressure (<0.5MPa) applied during the initial stage of the sintering process have been developed which form almost void free joints. To assess the strength of the sintered joints a high-temperature shear fixture has been designed. Shear tests have been performed at 25°C, 400°C, and 600°C to characterize the influence of high temperature conditions on the joint performance. The shear strength of the joints formed without pressure has been assessed for different Cu-to-Sn ratios at all temperature levels. It is shown that the maximum application temperature and shear strength depends on the ratio of low melting temperature and high melting temperature constituents. The pastes introduced here can be used to form joints resilient to application temperatures of up to 600°C. They show the potential to form joints for reliable operation under extreme temperature conditions.


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