(西北工業(yè)大學(xué)凝固技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室， 西安 710072
西安交通大學(xué)， 西安 710049)
摘 要: 推導(dǎo)了一個(gè)適用于中小尺寸板狀熔體表面電磁壓力的計(jì)算公式。該式給出了電磁壓力系數(shù) p與板厚a、電流頻率f、以及材料的電磁參數(shù)μγ之間的準(zhǔn)確關(guān)系。主要結(jié)果如下: (1) 當(dāng)f，a，以及μγ足夠大, 使得板的厚度a與電流集膚厚度δ的比a/δ>2. 2時(shí), 電磁壓力系數(shù)是一個(gè)常數(shù)( p=1), 電磁壓力可由公式 pm=B2/2μ計(jì)算。 (2) 但若f，a，以及μγ比較小，使a/δ<2.2，則電磁壓力必須由系數(shù) p進(jìn)行修正。也就是說，電磁壓力不僅由熔體表面的磁感應(yīng)強(qiáng)度 B 決定而且也由板的厚度a，電流頻率f，以及材料的電磁參數(shù)μγ決定。
關(guān)鍵字: 電磁約束成形 電磁壓力 磁感應(yīng)強(qiáng)度
（State Key Laboratory of Solidification Processing, Northwestern Polytechnic University, Xi'an 710072, P. R. China
Xi'an Jiaotong University, Xi'an 710049, P. R. China）
Abstract:An equation used to calculate electromagnetic pressure for confining and shaping a platelike melt with small or medium thickness is brought forward. The equation gives a precise relationship between electromagnetic pressure factor p and current frequency f, melt thickness a and electromagnetic parameter μγ. The main results can be summarized as follows: (1) As the f , a, and μγ are large enough, causing the ratio of melt thickness to current skining depth a/δ to be larger than 2.2, the p will be a constant( p=1) and the electromagnetic pressure can be calculated with pm=B2/2μ. (2) As the f, a, and μγ are not large enough, and the ratio a/δ is less than 2.2, the factor p is no longer a constant but changes from 1 to 0 with the decrease of a/δ. In this case, the value of electromagnetic pressure is determined not only by magnetic flux density B but also by the current frequency f, melt thickness a and electromagnetic parameter μγ.
Key words: electromagnetic confinement and shaping; electromagnetic pressure; magnetic flux density
