(1. 哈爾濱理工大學 材料科學與工程學院，哈爾濱 150040；
2. 哈爾濱工業(yè)大學 材料科學與工程學院，哈爾濱 150001)
摘 要: 通過有限元模擬和實驗，對不同摩擦擠壓過程中鋁合金變形流動行為的機理進行分析，并利用羅德系數(shù)和應力偏量不變量(J2)等特征量進行變形分區(qū)。結果表明：采用積極摩擦可使擠壓時的“死區(qū)”缺陷完全消失，且塑性區(qū)內材料的應變類型由3種變?yōu)榫坏睦祛愖兓@著地提高了擠壓過程中坯料橫斷面上金屬流速的均勻性，更利于金屬的擠出成形。
關鍵字: 擠壓；摩擦條件；數(shù)值模擬；應變類型；金屬流動行為
（1. School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China;
2. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China）
Abstract:The mechanical mechanism of the flow behavior of aluminum alloys during extrusion process with active friction was investigated by numerical simulations and experiments. The characteristic quantities such as the second invariant of the Lode parameter (μ) and deviatoric stress tensor (J2) were employed for the division of deformation area. The results show that when extruded with active friction, no metal flow interface forms at the container bottom, the dead metal zone completely disappears, the deformation types of the metal in the plastic deformation area change from three types to one type of tension. The homogeneity of the deformation as well as the metal flow is apparently improved, which will be helpful for extruding and promoting the quality of extrudates.
Key words: extrusion; friction condition; numerical simulations; deformation types; metal flow behavior
ISSN 1004-0609
CN 43-1238/TG
CODEN: ZYJXFK
ISSN 1003-6326
CN 43-1239/TG
CODEN: TNMCEW