钎缝间隙对SiC陶瓷钎焊接头组织及性能的影响  

Effect of joint clearances on microstructure and property of brazed SiC ceramics

作　　者：李卓然[1] 徐晓龙[1] 刘文波 卢治国 

机构地区：[1]哈尔滨工业大学先进焊接与连接国家重点实验室,哈尔滨150001 [2]哈尔滨东安机电制造有限责任公司,哈尔滨150066

出　　处：《焊接学报》2012年第11期9-12,113,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51075101)

摘　　要：采用Ti-Zr-Ni-Cu钎料,借助SEM,EDS和XRD等分析测试手段,研究了钎缝间隙对SiC陶瓷接头组织性能的影响.结果表明,接头结构由SiC侧至钎缝中心依次为TiC,Zr(s,s),Ti5Si3+Zr2Si,Ti(s.s)+Ti2(Cu,Ni),(Ti,Zr)(Ni,Cu).当钎缝间隙为30～50μm时,Si元素与Ti,Zr元素反应,生成少量的细小的针状硅化物,钎缝主要为均一的固溶体组织,此时钎焊接头力学性能较好,抗剪强度可达117 MPa;当钎缝间隙小于30μm时,生成贯穿整个钎缝的条状硅化物,同时有连续的、较厚的TiC层沿接头界面生成,严重降低接头性能;而当钎缝间隙大于50μm时,钛的金属间化合物大量增多,同时在钎缝中形成了钛和锆的过共晶化合物,使接头性能下降.The effect of joint clearance on microstructures and property of SiC ceramics brazed with Ti-Zr-Ni-Cu brazing filler was studied by means of SEM,EDS and XRD.The joint microstructure from SiC ceramics to the center of brazing seam are TiC,Zr(s,s),Ti5Si3+Zr2Si,Ti(s.s)+Ti2(Cu,Ni) and(Ti,Zr)(Ni,Cu) successively.When the joint clearance is 30 μm^50 μm,Si reacts with Ti and Zr element,and produces a small quantity of tiny needlelike silicon compounds.Homogeneous solid solution is full of the brazed joint.The mechanical property is superior and the shear strength can reach 117 MPa.When the joint clearance is less than 30 μm,longstring silicon compounds are generated,and run through the brazing beam.Meanwhile,successive and thick TiC layer is produced.Both of these two factors lower the mechanical property.When the joint clearance is more than 50 μm,Ti-based intermetallic increases and eutectic compounds are produced,which reduce the mechanical property.

关 键 词：SIC陶瓷 钎焊 界面组织 抗剪强度 

分 类 号：TG454[金属学及工艺—焊接]