Q.F. Zhu
,
Z.H. Zhao
,
J.Z. Cui
,
Y.B. Zuo
,
F. Qu
金属学报(英文版)
The influences of the low frequency
electromagnetic field on the horizontal direct chill casting process
were investigated experimentally. Ingots of 2024 aluminum alloy with
a cross size of 40~mm$\times$200~mm were produced by the
conventional horizontal chill casting process and low frequency
electromagnetic horizontal chill casting process，respectively. The
as-cast structures and the mechanical property of the ingots were
examined. The results showed that the low frequency electromagnetic
field could substantially refine the microstructures and
pronouncedly reduce the macrosegregation in the horizontal direct
chill casting process. Moreover, the surface quality of the ingot
was prominently improved by the low frequency electromagnetic field.
The fracture strength and elongation percentage of the ingot was
increased with the low frequency electromagnetic field.
关键词:
Horizontal direct chill casting
,
null
J. Dong
,
G.M. Lu
,
J.Z. Cui
金属学报(英文版)
In this study, reheating of liquidus semi-continuous east billets of 7075 Al alloy wascarried out in a resistance furnace, and the temperature contrast of the outer andthe center of the reheated billets was investigated, then the reheating microstructureswere investigated. Results show that: the difference of temperature between the outerand center is small and the difference of their microstructures are also small. Dur-ing reheating at 576° C the spheroidization of grains is significant after 5rain and norosettes are visible after 20min by optical microscopy. Similar observations were madeon materials reheated at 596° C, but the ripening process is faster. The grains growup to 30-60pm, fine enough for thixoforming.
关键词:
reheating
,
null
,
null
,
null
C. Y. Ban
,
J.Z. Cui
,
Q.X. Ba
金属学报(英文版)
The structures and macro-segregation of 2124 Al-alloy were studied when a pulsedmagnetic field (PMF) was applied during solidification. It is found through experi-ments that a remarkable change occurs in the solidification structures of 2124 Al-alloyunder pulsed magnetic field. The eutectic phase at grain boundaries change from thickcontinuous eutectic network to thin discontinuous one, and the distribution of soluteelements was also homogenized. The typical negative segregation phenomenon of Cu incommon solidification condition was restrained, and the segregation of Mg decreased.
关键词:
aluminium alloy
,
null
,
null
,
null
