Joining of Silicon Particle-Reinforced Aluminum Matrix Composites to Kovar Alloys Using Active Melt-Spun Ribbons in Vacuum Conditions

Abstract

<jats:p>The vacuum brazing of dissimilar electronic packaging materials has been investigated. In this research, this applies silicon particle-reinforced aluminum matrix composites (Sip/Al MMCs) to Kovar alloys. Active melt-spun ribbons were employed as brazing filler metals under different joining temperatures and times. The results showed that the maximum joint shear strength of 96.62 MPa was achieved when the joint was made using Al-7.5Si-23.0Cu-2.0Ni-1.0Ti as the brazing filler metal at 580 °C for 30 min. X-ray diffraction (XRD) analysis of the joint indicated that the main phases were composed of Al, Si and intermetallics, including CuAl, TiFeSi, TiNiSi and Al3Ti. When the brazing temperature ranged from 570 °C to 590 °C, the leakage rate of joints remained at 10−8 Pa·m3/s or better. When the joint was made using Al-7.5Si-23.0Cu-2.0Ni-2.5Ti as the brazing filler metal at 580 °C for 30 min, the higher level of Ti content in the brazing filler metal resulted in the formation of a flake-like Ti(AlSi)3 intermetallic phase with an average size of 7 µm at the interface between the brazing seam and Sip/Al MMCs. The joint fracture was generally in the form of quasi-cleavage fracture, which primarily occurred at the interface between the filler metal and the Sip/Al MMCs. The micro-crack propagated not only Ti(AlSi)3, but also the Si particles in the substrate.</jats:p>

Research on a Low Melting Point Al-Si-Cu (Ni) Filler Metal for 6063 Aluminum Alloy Brazing

“…It can be concluded that the microstructure of the Al-6.5Si-20Cu brazed joint was mainly composed of the α-Al phase, a coarse θ(Al 2 Cu) phase, and a Si phase. There was a small amount of Al 2 Cu intermetallic compound at the brazed joint interface, and some Si particles were embedded in the matrix [14,24]. Figure 9b-d show the microstructure diagrams of Al-6.5Si-20Cu-Ni brazed joints.…”

“…Chang et al [7] studied the brazing of 6061 aluminum alloy with Al-10.8Si-10Cu and Al-9.6Si-20Cu filler metals at 560 • C, and found that there are more θ(Al 2 Cu) brittle phases in the brazed joints, leading to a lower shear strength of the brazed joints (47 MPa and 67 MPa, respectively). The results indicate that adding an appropriate amount of Ni to Al-Si-Cu filler metal can replace part of the Cu and reduce the adverse effect of θ(Al 2 Cu) on joint properties [4,5,14]. Luo et al [4] developed Al-10Si-15Cu-4Ni filler metal with a melting range of 24.9 • C and successfully brazed 6061 aluminum alloy at 570 • C. Meanwhile, the joint shear strength was as high as 144.4 MPa, which was higher than that of Al-Si-Cu brazing filler metal [2,7].…”

Regeneration of Aluminum Matrix Composite Reinforced by SiCp and GCsf Using Gas Tungsten Arc Welding Technology

“…Aluminum matrix composites reinforced by silicon carbide (SiC) are a material solution successfully applied in the automotive field [ 8 , 9 , 10 ]. The popularity of these composites is due to a number of their properties, such as wear resistance, stiffness, compressive strength, low density, low coefficient of thermal expansion, good casting properties, and low production costs [ 11 , 12 ].…”

Joining of Hypereutectic Al-50Si Alloys Using Lead-Free Brazing Filler Glass in Air

“…They have potential applications in aerospace, automobiles, electronics, optical instruments, and sporting equipment, etc. [ 3 , 4 , 5 , 6 ]. In particular, for the T/R module of phased array radar, the weight of the phased array radar can be greatly reduced when hypereutectic Al-Si alloys are used to replace the commonly used Kovar alloy [ 7 , 8 ], which has important economic value.…”

“…Casalegno et al [ 28 ] joined carbon fiber reinforced polymer with Al-Si alloy by three different epoxy adhesives for space applications. Gao et al [ 5 ] studied the brazing of Si p /Al MMCs to Kovar alloy using active foil brazing filler metals in vacuum environment. Wang et al [ 29 ] joined hypereutectic Al-50Si alloys by ultrasonic-assisted flux-less soldering using Zn-5Al filler metal at 420 °C in air.…”