Effects of low frequency electromagnetic field on the as-cast microstructures and mechanical properties of superhigh strength aluminum alloy

Refining grain structure and porosity of an aluminium alloy with intensive melt shearing

“…Grain refinement is important for improving mechanical properties, reducing the size of defects and increasing the resistance to hot tearing, especially when producing large, highly alloyed ingots [1], [2] and [3]. Al-Ti-B master alloy is a good grain refiner for aluminium alloys [4] and [5]; however, it also causes other problems associated with melt contamination and formation of particles which cannot be removed by heat treatment.…”

“…Al-Ti-B master alloy is a good grain refiner for aluminium alloys [4] and [5]; however, it also causes other problems associated with melt contamination and formation of particles which cannot be removed by heat treatment. The search for new and effective grain refiners and methods for grain refinement continues [2], [3], [6] and [7]. Fan and his co-workers [8] have found that after an intensive shearing the oxide films entrained within melts can be dispersed uniformly in the melt and can act as nucleation centres, and thereby reduce the grain size.…”

The Mechanism Research of Electric Current Pulse and Electromagnetic for Grain Refinement of 6181 Aluminum Alloys During Two-roll Casting

“…In the field of materials, in the interest of reaching the above requirements, the research of light alloy and new methods of production has been a consequent trend. 6XXX aluminum alloys, which have been known as a kind of automotive materials, due to their low density, high specific strength, excellent plasticity, and good electrical conductivity [1][2][3]. However, how to reduce the manufacture costs and the improve formability of aluminum alloys sheets is required.…”

Mechanism of grain refinement of an Al–Zn–Mg–Cu alloy prepared by low-frequency electromagnetic casting

“…The LFEC process shows significant advantages including elimination or reduction of hot tearing [20] which is a key problem for the DC casting process [3,23,24] especially during the casting of large ingots of high strength Al-Zn-Mg-Cu alloys. It has been demonstrated by both experimental [17,19,25,26] and simulation studies [27,28] that the LFEC process can form a very uniform temperature field in the sump and significantly refine the microstructures of Al-Zn-Mg-Cu alloys, which is favourable for the elimination of hot tearings. The grain refinement by LFEC process in some other aluminium alloys was also studied and confirmed [29,30].…”

“…In the absence of effective nucleation substrates, dendrite fragments should be the major source of the equiaxed grain formation [31]. Therefore, the fragmentation caused by the forced convection has been used to explain the grain refinement [7,12,17,25,29,[32][33][34] under the influence of electromagnetic field. However, there is also another point of view that the forced convection cannot break the dendrite arm under normal solidification conditions [35,36].…”