摘要
针对传统纳米浸渍瞬态共晶(nano-infiltrated transient eutectoid,NITE)法连接碳化硅SiC陶瓷温度过高的问题,提出采用SiC基SiC-YF_(3)粉末为中间层对SiC陶瓷进行放电等离子(spark plasma sintering,SPS)扩散连接来降低连接温度,研究了连接温度、保温时间及氟化钇YF_(3)含量对接头组织和力学性能的影响.结果表明,连接温度与保温时间的增加可显著提高中间层粉末的组织致密度与接头力学性能,中间层主要以3C-SiC为主,另外也形成了富Si的SiC1-x、富C的SiC1+x、Y_(x)Cy和Y_(x)Si_(y)C_(z)等物相,接头物相组成与连接工艺相关.YF_(3)含量的增加会先形成Y_(x)Si_(y)C_(z),随后析出Y_(x)Cy,同时Y_(x)Si_(y)C_(z)含量减少,但尺寸增大,以至于接头组织的致密度和强度呈现出先提高后下降的趋势,而硬度逐渐上升.在最佳连接工艺与YF_(3)含量下(1750℃/10 min/5%YF_(3)),接头的中间层硬度为2013.1 HV±74.1 HV,与母材硬度相当,室温抗剪强度为181.9 MPa±55.2 MPa,且接头断裂在母材.
To address the issue of excessively high joining temperatures of silicon carbide(SiC)ceramics in the traditional nanoinfiltrated transient eutectic(NITE)method,a method utilizing spark plasma sintering(SPS)diffusion bonding with a SiC-based interlayer containing YF_(3) powder was proposed to reduce the joining temperature.The effects of joining temperature,holding time,and YF_(3) content on the microstructure and mechanical properties of the joints were investigated.The results indicate that increasing the joining temperature and holding time significantly enhances the densification of the interlayer powder and improves the mechanical properties of the joints.The interlayer is primarily composed of 3C-SiC,along with phases such as Si-rich SiC_(1-x),Crich SiC_(1+x),Y_(x)C_(y),and Y_(x)Si_(y)C_(z).The phase composition of the joints is influenced by the joining process.With increasing YF_(3) content,Y_(x)Si_(y)C_(z) initially forms,followed by the precipitation of Y_(x)Cy and a decrease in the amount but an increase in the size of Y_(x)Si_(y)C_(z).Consequently,the densification and strength of the joints first increase and then decrease,while the hardness gradually increases.Under the optimal joining process(1750℃/10 min/5%YF_(3)),the hardness of the interlayer reaches 2013.1 HV±74.1 HV,comparable to that of the base material.The room-temperature shear strength is 181.9 MPa±55.2 MPa,and fracture occurs within the base material.
作者
李华鑫
黄甫
李亚飞
闾川阳
贺艳明
杨建国
LI Huaxin;HUANG Fu;LI Yafei;LYU Chuanyang;HE Yanming;YANG Jianguo(Institute of Process Equipment and Control Engineering,Zhejiang University of Technology,Hangzhou,310023,China)
出处
《焊接学报》
北大核心
2025年第12期68-77,共10页
Transactions of The China Welding Institution
基金
国家自然科学基金(52005445,52471051,52175368,52375391)
浙江省自然科学基金(LQ21E050018)
中国博士后科学基金(2022M712820)。
关键词
碳化硅陶瓷
连接工艺
微观组织
力学性能
氟化钇
silicon carbide ceramic
joining process
microstructure
mechanical property
yttrium fluoride
