摘要
用ＤＴＡ、ＸＲＤ、ＳＥＭ、ＥＰＭＡ等研究了Ｎｂ镀层与ｃ－ＢＮ晶体在６０－１０００℃范围的界面反应过程、界面成分和结构特征，讨论了烧结时Ｎｂ镀层与ＳｉＯ２—Ｎａ２Ｏ－Ｂ２Ｏ３玻化结合剂的作用．结果表明：Ｎｂ镀层与ｃ—ＢＮ晶体在６００℃以上发生界面反应，外延生长形成ＮｂＮ，８００℃以上形成ＮｂＢ２，它们使Ｎｂ镀层与ｃ－ＢＮ牢固结合并阻止结合剂中的磁性组分对ｃ－ＢＮ的侵蚀，镀Ｎｂ的ｃ－ＢＮ表层的Ｎｂ则作为活性金属实现与玻化结合剂的化学健合．
In order to arrive at a high interface bond strength between the CBN grit and the borosilicate glass bond and eliminate any harmful chemical reaction during firing, the interface reaction process, interface composition and structure between Nb cladding and crBN at 600-100℃ are studied by DTA, XRD, SEM and EPMA. The composition, structure and properties of vitrified bond Nb clad c-BN composite materials during firing are discussed. Test result shows that interface reaction between Nb cladding and c-BN occurs above 60℃ through reaction diffusion, the epitaxial NbN and NbB2 are formed on the c-BN surface above 60℃ and 80℃ separately. The bending strength of composite materials fired at 90℃ 2h increases from 41 .90 MPa without cladding erBN to 53.0 MPa with Nb cladding c-BN and remaining c-BN in fired composite materials increases from 67% without cladding to 100% with Nb cladding c-BN, thus these Nb-ladding and epitaxial compound films grown on surface of c-BN improve the adhesion between the c-BN grit and the bond, prevent c-BN grit from corrosion during firing.
出处
《材料研究学报》
EI
CAS
CSCD
1995年第5期446-449,共4页
Chinese Journal of Materials Research
基金
国家85重点科技攻关项目
