摘要
介绍了自硬酚脲烷树脂砂工艺的特性和固化原理。分析了酚脲烷树脂砂铸件表面针孔缺陷的特点,提出聚异氰酸酯的局部过量是产生弥散性针孔缺陷的根本原因。只有提高混砂均匀性使两组分按一定的比例进行反应,才能从根本上解决针孔缺陷。现场试验表明,提高混砂机的混砂效果、降低树脂的粘度和延长混砂时间均能提高混砂均匀性,混砂均匀性提高后,铸件的针孔缺陷基本消除,质量良好。
The character and principle of curing of phenolic urethane resin no bake sand process was introduced. The characters of pinhole defects on the surface of casting which was produced with phenolic urethane resin sand were analyzed. The partial excess of polyisocyanate is the primary cause of dispersive pinhole defects. The pinhole defects can be solved fundamentally by improving the uniformity of sand mixing and making sure part I and II react at certain ratio. The field test shows that improving the performance of the mixer, decreasing the viscosity of resin and prolonging the mixing time can all improve the uniformity of sand mixing. After improving the uniformity of sand mixing, the pinhole defects of the casting were cancelled, quality remains excellent.
出处
《铸造》
CAS
CSCD
北大核心
2014年第7期704-708,共5页
Foundry
关键词
酚脲烷树脂砂
混砂均匀性
弥散性针孔
phenolic urethane resin sand
uniformity of sand mixing
dispersive pinhole
