摘要
To manufacture plate by the combination of equal channel angular processing （ECAP） and porthole die extrusion techniques, a novel technique, namely portholes-equal channel angular processing （P-ECAP）, was studied. Extrusion of AL6005A plate used for the bullet train plate was investigated by finite element method. The relevant porthole dies involving ECAP technique in channels were designed. Dimensional changes in the scrap part of the extrudate obtained after extrusion from the P-ECAP die, with different channel angles, were predicted. Effects of the channel angle and extrusion speed on the maximum temperature of the workpiece and other field variables were evaluated. At the channel angle of 160° of P-ECAP dies, the extrudate exhibited the optimal performance and the least amount of extrudate scrap was obtained. The optimal extrusion speed was 3-5 mm/s. Moreover, with the increase in ram speed from 1 to 9 mm/s, the peak extrusion load increased by about 49% and the maximum temperature was increased by about 70 ℃. The effective strain exhibited ascending trend in the comer of the ECAP deformation zone. In the solder seam and the side of die bearing of extrudate, the maximum principal stresses were tensile stress.
为了结合等通道转角和分流挤压技术生产板材,研究了一种等通道转角分流（P-ECAP）挤压新技术.通过有限元方法研究了用于高速列车的6005A铝合金板材的挤压.在传统分流模具的分流通道内设计了等通道转角工艺.预测了不同通道转角对P-ECAP工艺挤出板材的废料长度变化的影响;研究了通道转角和挤压速度对最大工件温度和其他场变量的影响.结果表明：板材在通道转角为160＆#176;时具有最好的尺寸精度,而且废料的尺寸也最小;较为合理的挤压速度为3～5 mm/s.另外,当挤压速度从1mm/s增加到9mm/s时,挤压力的峰值上升了49％,工件的最高温度升高了70℃.在通道内的转角变形区,等效应变有上升趋势;挤出板材的焊合区和模具边缘最大主应力为张应力.
基金
Project(B08040)supported by the Program of Introducing Talents of Discipline to Universities(111 Project),China
Project(2009ZX04005-031-11)supported by the National Science and Technology Special Program,China
