复杂镁合金铸件的水溶性砂芯材料及高效清理技术研究

Study on Water-Soluble Core Materials and Effective Cleaning Technology of Complex Magnesium Alloy Castings

为了解决复杂镁合金铸件成形及其清理困难的问题,开展了高性能的水溶性型芯材料和高效的型芯清理技术研究,主要研究了微波加热硬化硫酸镁砂芯的性能和树脂砂芯高效清理工艺。结果表明:微波加热硬化水溶性硫酸镁砂芯,具有良好的常温强度、高温溃散性及水溶性,但抗吸湿性较差,硫酸镁砂芯铸造镁合金铸件时、砂芯铸后可在较短时间内水溶溃散;型芯的清理效率随着Na OH溶液浓度、超声波功率和受热温度的增大而增加,随着激振力的增加先增大后减少,当清理液为清水时,溶解振动清理工艺不能清理覆膜砂试样,而溶解超声波清理工艺仍然具有一定的清理效果。

In order to improve the formability and cleaning of complex magnesium alloy castings, high-performance water-soluble mould cores and effective cleaning technology were studied in this paper. The performances of the water-soluble magnesium sulfate bonded sand core cured by microwave heating and effective cleaning technology ofprecoated sand cores were specifically investigated. The results show that the water-soluble magnesium sulfate bonded sand core cured by microwave heating possesses has many advantages including high room-temperature strength, good high-temperature collapsibility and high water-solubility rate, but its moisture resistance is poor. The water-soluble magnesium sulfate bonded sand core after casting magnesium alloy castings can be water-dissolved in a short time. The cleaning efficiency of sand cores increases with the increase of NaOH concentration, ultrasonic power and heating temperature, firstly increases and then decreases with the increase of exciting force. When cleaning solution is water, dissolution-vibration cleaning process can not clean the precoated sand cores, but dissolution-ultrasonic cleaning process still has some impact on the cleaning efficiency of the precoated sand cores.