【摘要】 采用BNi2+TiH2复合粉末钎料成功实现C/C复合材料与GH99镍基高温合金的钎焊,对焊后接头界面组织及力学性能进行了分析.结果表明,焊后接头典型界面结构为C/C复合材料/Cr3C2+MC+Ni(s,s)/MC+Ni(s,s)/Ni3Si+Ni(s,s)/Cr3C2+MC+Ni(s,s)/GH99高温合金.钎料中加入TiH2,可促进C/C复合材料母材的溶解,并在钎缝中部形成MC碳化物颗粒.随着TiH2含量的增加,钎缝中部MC形态由细小弥散向大片状转变.当TiH2含量为3%时,接头室温及800,1 000℃高温抗剪强度最高,分别可达40,19及10 MPa,接头强度高于BNi2钎料钎焊接头强度,并可有效保证接头高温使用性能.更多还原

【Abstract】 The brazing of C /C composite and GH99 nickel base superalloy was successfully performed using BNi2 + TiH2 brazing powder. The interfacial microstructure and mechanical properties of the brazed joints were investigated. The results show that,the typical microstructure of the joint is: C /C composite /Cr3C2+ MC + Ni( s,s) /MC + Ni( s,s) /Ni3Si + Ni( s,s) /Cr3C2+ MC + Ni( s,s) /GH99. With the increasing of content of TiH2,the dissolution of C/C substrate was enhanced,dispersed MC carbide particles formed in braze seam,and the modulus mismatch between C /C and filler alloy,the mechanical properties of the brazed joints were improved consequently. When using braze powder with 3% TiH2 addition, the maximum shear strength of the brazed joints were obtained,which were 40 MPa at room temperature,19 MPa at 800 ℃ and 10 MPa at 1 000℃. Comparing with brazed joints using BNi2 filler alloy,BNi2+ TiH2 joints possess higher strength,and the high-temperature properties of the joints can be guaranteed.更多还原