工艺参数对动态流量控制法挤压弯管应力的影响

采用有限元模拟和实验研究了挤压钛合金弯曲管件。通过实验验证了工件的形状和尺寸精度,并通过有限元模拟分析了工艺参数对挤出过程中变形体的平均压应力分布情况和挤出弯管件的曲率半径的影响规律。结果表明:有限元模拟中,弯管件的曲率半径误差为6.03%,弯管直径误差为3.82%;在靠近定径带处,平均压应力呈非均匀分布;在焊合腔内,靠近细分流孔区域的平均压应力小于靠近粗分流孔区域的平均压应力,平均压应力的大小顺序在通过粗、细分流孔前后相反;在模具结构固定不变时,弯管件的曲率半径随挤压速度的减小而增大,不随挤压温度的变化而变化。

Influence of process parameters on stress in extrusion bending tube by dynamic flow control method

The extrusion bending tube of titanium alloy was studied by finite element simulation and experiment. Then,the shape and dimensional precision of workpiece were verified by experiments,and the influence laws of process parameters on the average compressive stress distribution of deformed body during the extrusion process and the curvature radius of extruded bending tube were analyzed by finite element simulation. The results show that in the finite element simulation,the errors of curvature radius and diameter for bending tube are6. 03% and 3. 82%,respectively. Near bearing zone,the average compressive stress is non-uniformly distributed. However,in the welding cavity,the average compressive stress near the subdivided orifice area is smaller than that near the coarse orifice area,and the order of average compressive stress is reversed before and after passing through the subdivided and coarse orifices. In addition,when the mold structure is fixed,the curvature radius of bending tube increases with the decreasing of extrusion speed and does not change with the change of extrusion temperature.