(東北大學(xué) 材料電磁過(guò)程教育部重點(diǎn)實(shí)驗(yàn)室，沈陽(yáng) 110004)
摘 要: 研究了不同強(qiáng)度交變電磁場(chǎng)作用下，7075合金凝固殼高度及鑄錠表面質(zhì)量的變化規(guī)律。結(jié)果表明，隨著磁場(chǎng)強(qiáng)度增加，熔體與結(jié)晶器的接觸高度以及凝固殼高度減小，初凝殼形成位置點(diǎn)降低，鑄錠表面質(zhì)量提高。采用晶粒游離理論解釋了電磁場(chǎng)作用下初凝殼的形成機(jī)制，認(rèn)為電磁場(chǎng)作用下，晶粒從結(jié)晶器壁游離數(shù)量增加，穩(wěn)定初凝殼難以形成，是延緩初凝殼形成時(shí)間和降低初凝殼形成位置的根本原因。
關(guān)鍵字: CREM法；半連續(xù)鑄造；鋁合金；初凝殼
intensity and initial solidified shell height of
aluminum alloy produced by CREM process
（Key Laboratory of National Education Ministry for Electromagnetic
Processing of Materials，Northeastern University，
Shenyang 110004，China）
Abstract:Under the effect of electromagnetic field with low frequency，the evolutions of solidified shell height and surface aspects，bearing on 7075-aluminum alloy produced by CREM process，have been investigated. The results show that t he gradual enhancement of the electromagnetic intensity allows a decrease in the height of solidified shell and in the contact height between melt and mold，which improve surface aspects of the ingot. Crystal-dissociating theory are used to explain the formation mechanism of initial solidified shell under the effect of electromagnetic field. It is pointed out that under the effects of electromagnetic field, the decrease of crystal particles dissociated from the crystallizer wall results in the difficulty of formation of solidified shell，which is the key reason that delay the time an ddecrease the position of forming the initial solidified shell.
Key words: CREM process; semi-continuous casting; aluminum alloy; initial solidified shell
