高强度低发气量覆膜砂用酚醛树脂的研制

Development of a Phenolic Novolac for High strength, Low Gas evolution Coated Sand

研制成一种高强度低发气量酚醛树脂，用这种树脂混制的覆膜砂，在树脂加入量１．８％～２．５％时，常温抗拉强度３．０～４．５ＭＰ，热拉强度１．２～１．７ＭＰａ，发气量小于１７ｍｌ／ｇ。用于制壳不仅提高了壳型的尺寸精度和铸件质量。

A high strength,low gas evolution phenolic novolac has been developed,the tensile strength at room temperatures,hot tensile strength and gas evolution amount for a coating sand using this phenolic novolac were 3 0～4 5 MPa,1 2～1 7MPa and less than 17 ml/g respectively when the addition level of resin is the order of 1 8% to 2 5%.The phenolic novolac not only increases the dimensional precision of shell mold and quality of castings,but also cut down production cycle of shell mold.