消失模铸造模样材料结构及其燃烧性能研究

Study on Material Structure and Combustion Performance of Expendable Pattern Casting

通过美国康塔NOVA 2000e比表面积及孔径分析仪、扫描电子显微镜和差热热重同时测定装置对EPS和STMMA两种消失模材料的比表面积和显微结构进行了表征分析,实测了温度和时间对这两种材料燃烧性能的影响.结果表明:与EPS相比,STMMA的比表面积较大、粒径较小,且有较多的蜂窝状微孔;在相同的燃烧时间下,STMMA燃烧较快,残余物较少;在同一温度下,EPS和STMMA的残余率均随着燃烧时间的增加而减小,但STMMA的残余率更小;采用STMMA生产的铸件机加工5mm左右就无黑渣,较EPS底面的黑渣缺陷大幅度减少.

The specific surface area and microstructure of EPS and STMMA were analyzed by means of the NOVA 2000e specific surface area and pore size analyzer,SEM and differential thermogravimetric analysis.It measured the influence of temperature and time on the combustion of the two kinds of materials.The results show that compared with EPS,STMMA has larger specific surface area,smaller particle size,and more cellular micropores.At the same burning time,STMMA burned faster with fewer residues.Under the same temperature,the residual rate of EPS and STMMA decreased with the increase of combustion time,but the residual rate of STMMA is smaller.The castings produced by STMMA have no black slags while machined deep to around 5 mm,and the defects of black slags on the bottom of EPS is greatly reduced.