Interface microstructure and diffusion kinetics in diffusion bonded Mg/Al joint

Abstract

The interface microstructure, formation of diffusion bonded joint and regulation of atom diffusion were studied by means of scanning electron microscope (SEM), energy dispersion spectroscopy (EDS) and electron probe microanalyser (EPMA). The experimental results indicated that an obvious interfacial transition zone was formed between Mg and Al, and there are three intermetallic layers Mg 17 Al 12 , MgAl and Mg 2 Al 3 in this zone. Diffusion activation energy of Mg and Al in the above layers was lower than that in the Mg and Al base metals. The thickness (x) of each layer can be expressed as x 2 ＝ 4.14exp(-28780/RT)(t-t 0 ), x 2 ＝ 31.4exp(-25550/RT)(t-t 0 ) and x 2 ＝ 0.6exp(-22600/RT)(t-t 0 ) corresponding to Mg 17 Al 12 , MgAl and Mg 2 Al 3 with heating temperature (T) and holding time (t).

Microstructure and Mechanical Behavior of Al-Mg Composites Synthesized by Reactive Sintering

“…The Al-Mg bilayer composite hot-pressed at 573 K does not display any reaction product (Figure 6a-c). Because the diffusion coefficient of aluminum is higher than that of magnesium [76][77][78], it is plausible to assume that at a higher processing temperature (623 K) the aluminum atoms diffuse into the magnesium layer and form Al12Mg17 as the first reaction product (Figure 6d-f). The Al3Mg2 phase may then be generated by the additional diffusion of aluminum into the Al12Mg17 intermetallic and by the diffusion of magnesium into the Al matrix [79,80].…”

Experimental and Numerical Study of formation mechanism of dual-phase (AlCoCrFeNi)X HEAs brazed joints by reactive Ni/Al nano-multilayers

“…It can be seen that the higher the temperature, the more atoms cross the initial interface. In the experimental temperature range, the diffusion distance of elements and the width of the diffusion region increase with the increase of temperature, which can be explicated using the Arrehenius formula [53]:…”

Effect of Annealing Process on the Microstructures and Mechanical Properties of AZ31B/A356 Composite Plate Fabricated by Cast Rolling

“…Since the earliest intermetallic compounds need a certain transition time in which to nucleate, this time is referred to as the incubation period 22 . Therefore, the kinetic model linking the interfacial transition zone width, annealing temperature, and time is as follows 12,27 :…”

“…Nowadays, there are many types of processes available with which to fabricate Mg/Al composite plates, including: diffusion bonding 12,13 , explosive welding [14][15][16] , insert moulding 17 , compound casting 18,19 , hot-rolling 7,20,21 , and so on. Macwan et al 5 have investigated both hot and cold-rolling to fabricate Al/Mg/Al three-layer composite plate, and the subsequent annealing was implemented at temperatures of 200 ºC,250 ºC,300 ºC,350 ºC and 400 ºC for 0.5h,1h,2 h,4 h, which verifies the effects on the relationship between the microstructures and the mechanical properties.…”