SiC陶瓷表面增韧用环氧树脂基增韧剂的制备与性能研究

碳化硅陶瓷在磨削加工中极易产生崩碎损伤,在碳化硅陶瓷磨削层实时涂覆增韧剂是降低崩碎损伤的新方法。以E51双酚A型环氧树脂、无水乙醇、651型低相对分子质量聚酰胺树脂和1,8-二氮杂二环十一碳-7-烯(DBU)为主要成分制备了一种增韧剂,通过测量增韧剂在碳化硅陶瓷表层的接触角、浸润深度与固化时间,探究了增韧剂各组分的添加量与碳化硅陶瓷表面粗糙度对增韧剂润湿性能与固化速率的影响规律,优化出一种润湿性能好、固化速率快的增韧剂。结果表明:增韧剂的最佳质量配比为m(E51双酚A型环氧树脂)∶m(无水乙醇)∶m(651型低相对分子质量聚酰胺树脂)∶m(DBU)=1∶0.9∶0.5∶0.02,该增韧剂在碳化硅陶瓷表层的浸润时间约为160 s,浸润深度约为40 μm,可使碳化硅陶瓷的表层硬度降低约25%;增韧剂的润湿性能随着溶剂的增加或碳化硅表面粗糙度的增大而提高,促进剂添加量的改变对增韧剂的润湿性能几乎无影响;增韧剂的固化速率随溶剂的增加而降低,随促进剂的增加而提高,但当促进剂达到饱和时,固化速率不再提高。

Preparation and Properties of Epoxy Resin Based Toughening Agent for SiC Ceramics

SiC ceramics are prone to edge chipping during grinding.Real-time coating the grinding layer of SiC ceramics with a toughening agent is a new method to control the edge chipping.The toughening agent used in this research was prepared with E51 bisphenol A epoxy resin,anhydrous ethanol,651 low relative molecular weight polyamide resin,and 1,8-diazabicycloundec-7-ene(DBU)as its main ingredients.By measuring the control angle,wetting depth,and curing time of the toughening agent on the surface of SiC ceramics,the effects of the concentration of the toughening agent ingredients and surface roughness of ceramics on the wetting performance and curing rate of toughening agent were explored,and a toughening agent with good wetting performance and rapid curing rate was obtained.The results show that the optimal mass ratio of the toughening agents m(E51 bisphenol A epoxy resin)∶m(anhydrous ethanol)∶m(651 low relative molecular weight polyamide resin)∶m(DBU)is 1∶0.9∶0.5∶0.02.Under this configuration,the toughening agent penetrates the SiC ceramics surface to a depth of about 40μm within 160 s,which reduces the surface hardness of the SiC ceramics by about 25%.The wetting performance of the toughening agent increases with the increase of the amount of solvent or the increase of the surface roughness of SiC ceramics,which is found to be almost not affected by the amount of the accelerator.In addition,the curing rate of the toughening agent decreases with the increase of the amount of solvent,and increases with the increase of the amount of accelerator.However,when the amount of accelerator reaches saturation,the curing rate will no longer increase.