搅拌工具尺寸和工艺参数对塑料搅拌摩擦焊焊缝质量的影响

用不同尺寸的搅拌工具对聚氯乙烯(PVC)板材进行了搅拌摩擦对接焊工艺试验.试验证明,在搅拌工具肩部直径为30 mm,搅拌头直径为10 mm,搅拌头旋转速度为1 660 r/min,焊接速度为25 mm/min的情况下,可以得到焊缝饱满、成形美观的焊接接头.提高搅拌头的旋转速度可以成比例地提高焊接温度;焊接速度的影响较复杂,增大焊接速度一方面会降低焊接热输入,一方面又会间接地增大搅拌头的进给阻力,从而增大摩擦发热功率,提高焊接温度;搅拌工具肩部直径直接影响肩部与被焊材料表面的摩擦发热功率,增大肩部直径可以提高焊接温度,还有利于阻止焊缝材料的飞溅和外溢;而搅拌头直径的影响较复杂,增大它既可以提高搅拌头侧面与被焊材料之间的相对运动线速度,从而提高焊接温度,又会增加被焊材料的吸热功率和传热面积,从而降低焊接温度.

EFFECTS OF TOOL DIMENSIONS AND WELDING PARAMETERS ON THE QUALITY OF PLASTICS FSW JOINTS

The experiments of plastics FSW with different dimensional stir tools were carried out. The tests showed that a full and smooth joint can be obtained with 30 mm in shoulder diameter, 10 mm in pin diameter, 1660 r/min in rotation speed and 25 mm/min in welding speed. The welding temperature was directly proportional to rotation speed. The effect of welding speed was complex, increasing welding speed reduced the heat input and increased the normal force Fx acting on the pin, friction heat power and welding temperature. The diameter of tool shoulder can affect the friction heat power between the shoulder and the welded surface, increasing the diameter of tool shoulder can increase the welding temperature and be helpful for the overflow and splash of the welding material. The effect of pin diameter is complicated, increasing the diameter increases the relative sliding speed between the pin and the welded material, which leads to the increasing of the welding temperature, meanwhile increasing the diameter increases the endotherm power and the area for heat transfer, which reduces the welding temperature.