真空低压消失模壳型铸件表面质量改善研究  

Surface Quality Improvement of Castings by Expendable Pattern Shell Casting with Vacuum and Low Pressure

作　　者：蒋文明[1] 樊自田[1] 廖德锋[1] 赵忠[1] 刘德均[1] 

机构地区：[1]华中科技大学材料成形与模具技术国家重点实验室,湖北武汉430074

出　　处：《铸造》2011年第2期140-143,共4页Foundry

基　　金：国家高技术研究发展计划(863计划)资助项目(2007AA03Z113);国家自然科学基金项目(51075163)

摘　　要：系统地考察了泡沫模表面质量、型壳表面质量以及金属与铸型间的润湿等因素对铸件表面质量的影响规律,并提出相应的改善措施。结果表明:泡沫模珠粒间的沟槽对型壳及铸件表面质量造成较大的影响。通过在泡沫模表面涂挂光洁剂,可以显著提高型壳和铸件的表面质量。增大泡沫模的密度也可以提高铸件的表面质量。涂料性能对铸件表面质量也有很大影响,硅溶胶型壳强度高、表面质量较好;随着粉料目数的增大,铸件表面质量不断提高。由于金属液与型腔不润湿,型腔与金属液间气膜的存在会对铸件表面质量有一定的影响,应设法消除或削弱气膜;采用真空和压力下浇注,可以减小气膜,提高铸件表面质量。Influences of surface quality of foam pattern and ceramic shell as well as wettability between metal and mold on surface quality of castings were investigated, and the corresponding improvement measures were proposed. The results indicate that the grooves of foam pattern have great effect on the surface qualities of shell and castings. Through coating the smooth agent on surface of the foam pattern can improve greatly the surface qualities of shell and castings. Meanwhile, the surface quality of castings is increased with increase of the density of the foam pattern. In addition, the coating＇s performance also has great effect on the surface quality of castings. The shell prepared using silica sol has better surface quality and high strength. The surface quality of castings is gradually improved with the increase of powder mesh. The gas film between metal and mold has effect on the surface quality of castings because the metal does not wet the mold. Therefore, the gas film should be decreased or even avoided. Pouring under vacuum ＆ low pressure condition can decrease the gas film, so that the surface quality of castings can be improved.

关 键 词：真空低压铸造 消失模铸造 壳型铸造 泡沫模 型壳 沟槽 气膜 

分 类 号：TG249.5[机械工程—精密仪器及机械]