自生成钨基高密度合金中间层的钨/钢真空扩散连接  

Diffusion Bonding Tungsten to Steel in Vacuum with Tungsten Heavy Alloy Interlayer Formed on Tungsten Surface

作　　者：杨宗辉[1,2] 沈以赴[1] 李晓泉[2] 

机构地区：[1]南京航空航天大学材料科学与技术学院,南京211106 [2]南京工程学院材料工程学院,南京211167

出　　处：《机械工程学报》2013年第4期58-63,共6页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51075205);江苏省自然科学基金(BK2007201)资助项目

摘　　要：采用90W-6Mn-4Ni(质量分数)混合粉末/镍箔复合中间层,在加压5 MPa、连接温度1 100℃、保温10 min、30 min、60 min及120 min的工艺条件下,对纯钨(W)和0Cr13钢进行真空扩散连接。利用扫描电镜、能谱仪和电子万能试验机等手段研究接头的微观组织、成分分布、力学性能及断口特征。结果表明,连接接头均由钨母材/钨基高密度合金层/镍/钢母材组成。接头中的钨基高密度合金层由90W-6Mn-4Ni混合粉末液相烧结生成,其富Mn-Ni黏结相和钨颗粒相冶金结合且分布均匀,保温时间对该层的组织形态无明显影响。钨基高密度合金层与钨母材以加压钎焊机制实现了良好结合。接头抗剪强度为202～217 MPa时,断裂均发生在连接界面两侧的钨母材和钨基高密度合金层中,前者断口为典型的解理脆断,后者断口为钨颗粒相的W-W界面分离断裂及黏结相的韧性断裂。Bonding between tungsten and 0Cr13 steel using a 90W-6Mn-4Ni （mass fraction） powder mixtures/Ni multi-interlayer, was carried out in vacuum at 1 100℃ for 10 min, 30 min, 60 min, 120 min with 5 MPa. The microstructures, composition distribution and fracture characteristics of the joints are studied by scanning electron microscope（SEM）, energy dispersive spectroscopy（EDS） and their mechanical properties are tested by shear experiments. The results show that the joints comprised tungsten/tungsten heavy alloy layer/Ni/0Cr13 steel. Among them, the tungsten heavy alloy layer is formed through liquid phase sintering of 90W-6Mn-4Ni mixed powder. Holding time has no significant effect on the microstructure of tungsten heavy alloy layer, which composes of metallurgical bonded and evenly distributed MnNi-rich phase and tungsten phase. Good bonding between tungsten matrix and tungsten heavy alloy layer is realized based on press brazing mechanism. The shear strength of joints is from 202 MPa to 217 MPa. All fractures occur in bonding zone of tungsten matrix and tungsten heavy alloy layer. The typical cleavage fracture of tungsten matrix and the tungsten phase interface debonding fracture accompanied by MnNi-rich phase ductile fracture of tungsten heavy alloy layer are observed in the fracture surfaces.

关 键 词：钨 钨基高密度合金 连接 抗剪强度 

分 类 号：TG457[金属学及工艺—焊接]