發(fā)布時間：2018-02-27 10:20

  本文關(guān)鍵詞： 晶粒細化 異質(zhì)形核 脈沖磁場 小潤濕角 臨界形核半徑 臨界形核過冷度　出處：《東北大學(xué)學(xué)報(自然科學(xué)版)》2015年04期 　論文類型：期刊論文

【摘要】：基于Ma形核模型,理論分析了異質(zhì)形核基底小潤濕角下脈沖磁場金屬凝固的異質(zhì)形核過程,建立了凝固形核模型.考察脈沖磁場磁感應(yīng)強度對金屬凝固臨界形核半徑及臨界形核過冷度的影響.結(jié)果表明:該模型中體系Gibbs自由能與異質(zhì)形核基底形狀系數(shù)無關(guān).在低過冷度金屬凝固條件下,當(dāng)脈沖磁場磁壓力功與金屬熔體固液自由能差在同一數(shù)量級時,脈沖磁場可有效減小凝固形核的臨界半徑;在大過冷度(大于20℃)金屬凝固條件下,脈沖磁場對金屬凝固臨界形核半徑的影響可忽略.金屬凝固異質(zhì)形核基底粒徑較大時,臨界形核過冷度隨脈沖磁場磁感應(yīng)強度增大而有效減小.
[Abstract]:Based on the Ma nucleation model, the heterogeneous nucleation process of metal solidification in pulsed magnetic field at small wetting angle of heterogeneous nucleation substrate is theoretically analyzed. A solidification nucleation model was established. The influence of magnetic induction intensity of pulsed magnetic field on the critical nucleation radius and the critical nucleation undercooling of metal solidification was investigated. The results show that the Gibbs free energy of the system and the shape coefficient of the heterogeneous nucleation substrate in the model are obtained. No. Under the condition of solidification of metal with low undercooling, When the magnetic pressure work of the pulsed magnetic field is of the same order of magnitude as the solid-liquid free energy of the metal melt, the critical radius of the solidification nucleation can be effectively reduced by the pulsed magnetic field, and under the condition of large undercooling (> 20 鈩，

本文編號：1542257