Study On The Effect Of Ultrasonic On Wettabiliy Of Solder And Iron-based Amorhpous

Amorphous alloys possess some advanced mechanical properties for its special long range non-ordered structure. For example, Fe-based amorphous alloys have excellent soft magnetic properties,which makes them be paid much attention in recent years. However, they easily crystallize under a high temperature, which lead s to the difficult y in connecting them with other materials. Relatively, soldering is an effective method, but the reports on wettability of fillers on amorphous alloys are few. This work mainly focused on the wettability between amorphous alloy and melting filler alloy and the kinetics of interfacial compound growth. the multiple amorphous foils were successfully joined with the method of ultrasonic-assisted soldering.The wetting behavior of molten solder on Fe77.5Si13.5B9 amorphous alloys using sessile drop method was investigated, and the effect of ultrasound on it was studied; Then the interfacial metallurgical reaction, and the kinetics of interfacial compounds growth were explored; At last the Fe77.5Si13.5B9 amorphous alloys were stack joined by ultrasonic- assisted soldering. Futhermore, the effect of ultrasound and the crystallization extent of the amorphous alloys on the kinetics of interfacial compounds growth were systemly studied.Wettability test results showed that: with the increase of ultrasonic power and time, and the rise of temperature, the wetting properties of Sn-9Zn solder and pure Sn solder on Fe77.5Si13.5B9 amorphous alloy were significantly improved; the wettability of solders on the original amorphous alloy was the best, partly crystallized amorphous alloy was the next, while the wettability on crystallized Fe77.5Si13.5B9 alloy was the worst. However, it was the most sensitive to ultrasound for crystallized Fe77.5Si13.5B9 alloy.According to the observation and measurement of the interfacial compounds as function of aging temperature and time with increase of the aging time and aging temperature, the thickness of the interface compound gradually increased. By EDS spectroscopy and micro- XRD analysis, the interface compound was identified as Fe Zn13. By calculation, without ultrasound, the activation energy of the amorphous Fe77.5Si13.5B9/Sn-9Zn system was the greatest, followed by crystallized Fe77.5Si13.5B9/Sn-9Zn system, and the activation of partially crystallined Fe77.5Si13.5B9/Sn-9Zn system was the smallest. Assisted by ultrasound, the activation energy of all three systems increased. The activation energy of crystallized Fe77.5Si13.5B9/Sn-9Zn system increased the most, which means crystallized Fe77.5Si13.5B9 alloy is more sensitive to ultrasound.The mult iple Fe77.5Si13.5B9 amorphous alloy foils were soldered by ultrasonic-assisted soldering. The SEM results showed that after the application of ultrasound, the interface connected more continuous ly, with no obvious defects. At the same time, the interfacial compound Fe Zn13 grew significantly after aging. Hardness test results showed that: with the increase of ultrasonic power and time, the hardness of the weld zone continuously improved, while the effect of temperature was little; also the XRD results showed that the alloy remained amorphous. Therefore, ultrasound-assisted soldering methods can effectively connect Fe77.5Si13.5B9 amorphous alloys, which will provide a theoretical support and the basis of experiments in expanding the application of Fe77.5Si13.5B9 amorphous al oy.