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数值模拟和实验研究了6201合金管材连续流变扩展挤压成形过程中的温度场分布和熔体流动规律。结果表明,在连续流变扩展挤压6201合金管材过程中,辊-靴型腔中的合金等温线向轧辊侧偏移,随着浇注温度的升高半固态区间逐渐下移;在辊-靴型腔中合金熔体服从牛顿流体的层流运动规律,从工作辊表面向靴表面速度依次递减,在靴表面速度为0 m·s~(-1);在扩展挤压模中合金呈辐射状逐层填充扩展腔,并发生分流-汇合流动,呈现出均匀的层流流动,在模具中心和分流孔流动速度最大,并逐渐向侧壁递减;与分流孔中心位置和焊合部位对应的成形管材横断面流线密集,在两者之间出现一个流线舒缓的过渡地带;制备6201合金管材的合理浇注温度范围为750-780℃。
Numerical simulation and experimental study of 6201 alloy pipe continuous rheological expansion during extrusion temperature distribution and melt flow law. The results show that the alloy isotherm in the roller-shoe cavity shifts to the roll side during continuous flow expansion and extrusion of the 6201 alloy pipe. The semi-solid section gradually decreases with the increase of the pouring temperature. In the cavity, the alloy melt follows the laminar motion of Newtonian fluid, decreasing from the surface of the work roll to the surface of the shoe in turn, with the velocity of 0 m · s -1 at the surface of the shoe. In the extended extrusion die, Shaped filling expansion chamber layer, and the diversion - convergence flow, showing a uniform laminar flow, the mold center and the diversion hole flow velocity and gradually decreased to the side wall; and the center of the shunt hole and weld corresponding parts The cross section of the shaped pipe has a dense streamline, and a streamlined soothing transition zone appears between the two. The reasonable pouring temperature range for preparing the 6201 alloy pipe is 750-780 ° C.