Cr镀层对立方氮化硼(cBN)－玻化陶瓷复合材料界面成分、结构的作用

THE INFLUENCE OF Cr-CLADING ON INTERFACE STRUCTURE AND COMPOSITION OF cBN-BOROSILICATE GLASS COMPOSITE MATERIALS

摘要: 本文用DTA、XRD、SEM、EPMA等研究了Cr镀层与cBN晶体在600～1000℃范围的界面反应过程,以及界面成分结构特征,讨论了Cr镀层在烧结时与SiO₂-Na₂O-B₂O₃玻化结合剂的的作用。结果表明,Cr镀层与cBN晶体在600℃以上发生界面反应形成CrN,800℃以上开始形成CrB₂,这些在cBN晶体上外延生长的难熔化合物使Cr镀层与cBN牢固结合并阻止了结合剂中碱性组分对cBN的侵蚀,实现了cBN与玻化结合剂间的化学键结合。

Abstract: The interface reaction process,interface composition and structure between Cr clading and cBN at 600-1000℃ were studied by DTA,XRD,SEM and EPMA.The composition,structure and properties of vitrified bond-Cr clad cBN composite material during firing are discussed.Test results show that interface reaction between Cr clading and cBN occurs above 600℃ through reaction diffusion,and the epitaxial CrN and CrB₂ form on the cBN surface above 600℃ and 800℃ separately.The Cr clading and epitaxial compound film cBN on surface of cBN improve the adhesion between the cBN grit and the bond,preventing grit from corrosion during firing.