Effects of Die Steel on Die Soldering of Aluminum Alloy Die Casting

This study carried out a die soldering test using both H13 and 1045 steel to investigate the different performances of these two substrate materials with regard to die soldering. Aluminum alloys with various amounts of silicon (0, 4.5, and 9 wt.%) were used to investigate the action of silicon in the soldering reaction, with the 0 wt.% material being commercial pure aluminum. Aluminum alloy samples of varying Si content were melted and held at 680oC and both H13 and 1045 steel were dipped for two hours in the melt. After the dipping test, the specimens were air cooled and analyzed using SEM and EPMA. The reaction layer of the H13 steel and the aluminum alloys were composed of Al3Fe (ɵ), Al5Fe2(η) and Al8Fe2Si (τ5) phase. The reaction layer between the 1045 steel and the aluminum melt was composed AlFe (ζ), Al5Fe2 (η), Al3Fe (ɵ), and Al8Fe2Si (τ5). The reaction layer thickness with the H13 substrate increased with the Si content of the aluminum; it deceased with increased Si content with the 1045 steel substrate.

Effect of TiO2 on the Formation of Primary and Interfacial Cu6Sn5 in Sn-0.7wt%Cu and Sn-0.7wt%Cu-0.05wt%Ni Solder Paste during Soldering

This paper investigates the effect of 1 wt% TiO2 on the formation of primary and interfacial Cu6Sn5 in Sn-0.7wt%Cu and Sn-0.7wt%Cu-0.05wt%Ni solder pastes soldered on a Cu substrate using a real-time synchrotron imaging technique. It was found that TiO2 had altered the nucleation time of the primary Cu6Sn5 intermetallics and increased the number of particles observed. In addition, a more planar Cu6Sn5 interfacial layer had formed in joints made with TiO2 reinforced solders. This indicated that TiO2 promotes nucleation of primary Cu6Sn5 intermetallics in the early stages of soldering while being a barrier for further growth of interfacial Cu6Sn5 intermetallics. The synchrotron imaging technique provides direct evidence of the sequence of events in the soldering reaction and how these are influenced by TiO2 reinforcement.

In situ visualization of metallurgical reactions in nanoscale Cu/Sn diffusion couples

The Cu–Sn metallurgical soldering reaction in two-segmented Cu–Sn nanowires is visualized by in situ transmission electron microscopy.