带背压等径角挤压力的滑移线解析及背压作用分析
Analysis of Slip-line of Extrusion Force of ECAP with Back Pressure and Its Effect
李永志1，2， 白小波1， 谢玉敏1， 纪良波1
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作者单位：1.九江学院 机械与材料工程学院，江西 九江 332005； 2.合肥工业大学 材料科学与工程学院，安徽 合肥 230009
中文关键字： 等径角挤压； 背压； 滑移线解； 挤压力； 验证
英文关键字： equal channel angular pressing(ECAP); back-pressure; slip-line solution; extrusion force; verification
中文摘要：运用滑移线理论推导出了带背压一道次ECAP的挤压力理论解析式，并运用Deform-3D软件对铝材的带背压ECAP过程进行了模拟验证。结果表明：挤压力的滑移线理论解与模拟均值相符；背压扩大了ECAP过程塑性变形区域，提高了材料塑性变形均匀性及应变能力，细化了晶粒；施加背压大小不变时，摩擦系数越大、模具内、外角越小，ECAP所需挤压力也越大，对模具结构、优化设计的要求越高。
英文摘要：Using slip-line theory, the analysis formula of extrusion force in ECAP with back pressure during a single pass was derived, and which was simulated and validated by Deform-3D software and Al material. The results show that the theory results are generally consistent with simulation results; and the back pressure has many beneficial effects in expanding deformation zone and enhancing effective strain and deformation uniformity; under constant back pressure, the greater the friction coefficients are, the smaller the die angles and exterior angles are, the greater the needed extrusion stress, and the higher the demands on die structure and optimization are.