摘要
针对新型耐高温复合材料(SiCf/SiC)的加工性差的问题,采用AuCuTi/Mo/AuCuTi复合钎料对其与镍基高温合金进行钎焊研究。通过探究不同温度下的接头力学性能及组织演变规律,对界面反应和应力缓释机理进行分析。在1 050℃/10 min的工艺参数下,接头室温剪切强度最高达到79 MPa。接头典型的界面结构为GH536/(Ni,Cr,Mo,Fe)+TiNi_(3)+Ti_(2)Ni+AuCuI/TiNi_(3)+Ti_(2)Ni+TiNi+AuCuI/σ/Mo/Mo_(4.8)Si_(3)C_(0.6)/Ti_(5)Si_(3)Cx/Ti_(5)Si_(3)Cx+TiC+AuCuI/Ti_(3)SiC_(2)/SiCf/SiC。当温度较低时,界面反应程度较低,因此陶瓷/钎料异质界面难以形成连续的Ti_(5)Si_(3)C_(x)+TiC连接层;而当钎焊温度增加到1 050℃时,异质界面处开始形成厚度约为3μm的Ti_(3)SiC_(2),从而实现有效地连接。当温度继续升高到1 100℃时,Cr元素在Mo箔中的扩散程度增加,并在陶瓷/钎料异质界面处发生富集。而此时过厚的界面反应层(10μm)则是引起接头剪切降低的主要原因。使用该钎焊体系有助于阻碍母材之间的剧烈反应以及缓解接头的热应力,在一定程度上改善了SiCf/SiC在实际应用中的加工困难问题。
Aiming at the poor workability of the novel high-temperature-resistant composites(SiCf/SiC),the brazing of SiCf/SiC and a Ni-base superalloy is studied.The mechanical properties and microstructural evolution of joints at different temperatures are studied,and the corresponding mechanism is clarified.Under the process parameters of 1 050℃/10 min,the room temperature shear strength of the joint reaches 79 MPa.The typical interface structure of the joint was GH536/(Ni,Cr,Mo,Fe)+TiNi_(3)+Ti_(2)Ni+AuCuI/TiNi_(3)+Ti_(2)Ni+TiNi+AuCuI/σ/Mo/Mo_(4.8)Si_(3)C_(0.6)/Ti_(5)Si_(3)Cx/Ti_(5)Si_(3)Cx+TiC+AuCuI/Ti_(3)SiC_(2)/SiCf/SiC.When the temperature is low,the interface reactions are limited.Therefore,it is difficult to form a continuous connection Ti_(5)Si_(3)C_(x)+TiC layer at the ceramic/braze heterogeneous interface.When the brazing temperature increases to 1 050℃,a 3μm layer of Ti_(3)SiC_(2) newly forms at the heterogeneous interface to achieve efficient connection.When the temperature continues to rise to 1 100℃,the diffusion of Cr element in Mo foil increases,and an enrichment of Cr occurs at the heterogeneous interface of ceramic/braze.Currently,the excessively thick interfacial reaction layer(10μm)is the main reason for the reduction of joint shear strength.The use of this brazing system helps to hinder the violent reactions between the base materials and relieve the thermal stress of the joint,which reduces the processing difficulty of SiCf/SiC in practical applications.
作者
杨佳
张勋业
马广璐
林盼盼
徐彦强
林铁松
何鹏
YANG Jia;ZHANG Xunye;MA Guanglu;LIN Panpan;XU Yanqiang;LIN Tiesong;HE Peng(State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001;AECC Shenyang Liming Aero-Engine Co.,Ltd,Shenyang 110043;Institute for Advanced Ceramics,Harbin Institute of Technology,Harbin 150080)
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2021年第12期161-168,共8页
Journal of Mechanical Engineering
基金
国家磁约束核聚变能发展研究专项(2019YFE03100100)
国家自然科学基金(51805112,51974101,51975150)
装备预研领域基金(61409230512)
黑龙江省自然科学基金(LH2020E037)
山东省重大科技创新工程(2019JZZY010366)资助项目。
