树脂砂受限热膨胀力的研究

Research on Restraining Load of Resin Sand

树脂砂的高温力学性能直接关系到铸件质量的好坏,受限热膨胀力是树脂砂高温力学性能中非常重要的一项,可以综合反映型(芯)砂本身的膨胀和其容纳热膨胀的能力。根据检测的树脂砂受限热膨胀力的数据可预测型(芯)砂裂纹的产生、进而预测铸件脉纹缺陷的产生与否。本研究采用自行研制的树脂砂高温力学性能仪,主要检测酚醛树脂覆膜砂、自硬呋喃树脂砂这两类树脂砂的受限热膨胀力,以找出树脂砂受限热膨胀力与原砂种类的关系。结果表明,ZSK140/70覆膜砂受限热膨胀力最高,为29.1 N,特种覆膜砂次之,为20.9 N,宝珠覆膜砂最低,为16.8 N。采用大林标准砂为原砂的自硬呋喃树脂砂受限热膨胀力最高,为23.4 N,其次是刚玉复合砂,为22.8 N,再生砂的受限热膨胀力最低,为15.1N。

High temperature properties of resin sand directly concern the quality of castings. Restraining load is one of the most important high temperature properties. It can reflect the expansion of the sand mixture itself and its capacity to accommodate thermal expansion. The detection data of resin sand restraining load can predict the crack of the mold, and the casting veining defect of the casting production. A self-developed instrument for the high temperature mechanical properties of resin sand was adopted in this study. In order to find out the relationship between the restraining load and the base sands, restraining load of precoated sand and no-bake furan resin sand was detected in this study. The results show that the restraining load ofZSK140/70 precoated sand is the highest, the data is 29.1 N, the second is special precoated sand, the data is 20.9 N, and the data of pearl precoated sand is 16.8 N. The restraining load 23.4 N of no-bake furan resin sand is the highest, which was prepared with standard sand, the second is corundum composite sand, the restraining load is 22.8 N, and the data of reclaimed sand is 15.1 N.