Ag-Cu-In-Ti钎料钎焊SiO_(2f)/SiO_2复合材料与钼合金的接头组织及机理

Microstructures and joining mechanism of vacuum brazing of SiO_(2f)/SiO_2 composite to Mo alloy using Ag-Cu-In-Ti brazing fillers mechanism

设计了3种Ag-Cu-In-Ti钎料,在800℃/10 min工艺下实现了Si O2f/Si O2复合材料与钼合金的连接.室温下测试了接头的抗剪强度,通过扫描电镜、电子探针、能谱仪和X射线衍射仪分析了接头的微观组织和界面产物.结果表明,1号钎料所得接头平均抗剪强度最高,为24.1 MPa,其中Ti元素发挥了活性作用而富集在母材两侧的反应层,与Si O2发生反应为Ti+Si O2→Ti Si2+Ti O,伴随反应为Ti+Cu+O→Cu3Ti3O,并有一部分以Cu3Ti的形式块状分布在钎缝中,提高了接头的强度.1号钎料接头产物依次为Si O2→Cu3Ti3O+Ti O+Ti Si2→Ag(s,s)/Cu3Ti/Cu(s,s)→Cu3Ti+Ti O→Mo.

Three kinds of Ag-Cu-In-Ti brazing filler were designed for joining of SiO 2f/ SiO 2composite to Mo alloy. The brazing experiment was conducted at 800 ℃ for 10 min under vacuum condition. The joint shear strengths were tested at ambient temperature. The microstructures were observed under a scanning electron microscopy( SEM),and the reaction products were analyzed by EPMA,EDS and XRD. The results show that the joints brazed with 1#brazing filler offer the maximum shear strength of 24. 1 MPa. Part of Ti element is enriched at interfacial reaction layer,the other part is distributed within the joint matrix as Cu3 Ti to enhance the joint. The mechanism of joiningSiO 2f/ SiO 2composite by Ag-Cu-In-Ti brazing filler is the reaction of Ti with SiO 2: Ti + SiO 2→TiS i2+ TiO,followed by the subsequent reaction: Ti + Cu + O → Cu3Ti3 O. The product sequence for 1#joint can be described as the following: SiO 2→Cu3Ti3O +TiO + TiS i2→Ag( s,s) /Cu3 Ti / Cu( s,s) →Cu3Ti + TiO →Mo.