镁合金管高速滚珠旋压变形区温升特性研究

Research on Temperature Rise Characteristics of Deformation Zone of Magnesium Alloy Tube by High Speed Ball Spinning

摘要:

滚珠旋压由于连续逐点成型特性而产生大量的变形热而需要对变形区进行连续冷却。由于镁合金成型温度较低的特点,可以利用摩擦与变形热替代镁合金薄壁管滚珠旋压工件的加热过程。本文通过有限元模拟对不同工艺参数下的生热规律进行了计算,结果表明：滚珠旋压变形影响区的温度随着摩擦系数,模具转速,减薄量和进给比的提高而增加,其中,减薄量对温度的提高最为敏感,模环转速对温度的提高影响较小,摩擦系数对温升的影响最小；在高转速和大减薄量时变形影响区的温度可以达到220℃以上,可以满足镁合金的温热成形的温度要求。变形区非接触式温度测量结果表明模拟结果与实测结果吻合度较高。

Abstract:

Ball spinning often requires a continuous cooling of the deformation zone due to the large amount of deformation heat generated by the continuous point-by-point molding characteristics. According to the low forming temperature of magnesium alloy, this paper uses friction and deformation heat to replace the heating process of the thin-walled magnesium alloy tube in ball spinning process. The heat generation laws under different process parameters are calculated by finite element simulation. The results show that the temperature in the spinning deformation zone increases with the increase of rotating speed, thinning amount, feed ratio and friction coefficient. For these four parameters, the friction coefficient has little effect on the temperature increase. The amount of thinning is the most sensitive to the increase of temperature, the effect of mold speed on the increase of temperature is little, and the friction coefficient has the least influence on the temperature rise. Under high speed and larger amount of thinning, the temperature of the deformation zone can reach more than 220℃, which can meet the temperature requirement of hot forming of magnesium alloy. The results of non-contact temperature measurement in the deformation zone show that the simulation results are in good agreement with the measured results.