摘要
SiC陶瓷凭借其高强度、高硬度和低密度等优势,在航空航天、核电工业等领域有着广阔的应用前景。但由于SiC加工难度高、韧性低,阻碍了其广泛应用。为解决上述问题,本研究采用黏结剂喷射增材制造(BJAM)结合液硅反应熔渗技术(LSI)制备了不同碳化硅晶须含量(SiC_(w))的SiC_(w)/SiC复合材料。结果表明,当SiC_(w)含量达到7.5%(体积分数)时,材料的弯曲强度和断裂韧性达到最大值分别为215.29 MPa和3.25 MPa?m^(1/2),硬度则在SiC_(w)为5%达到23.06 HV的峰值。但当SiC_(w)含量继续升高后,材料内部残余硅相含量提升,力学性能发生恶化。对打印初坯进行2次增碳可有效降低材料内部硅相含量,弯曲强度、断裂韧性和硬度最大分别提升10.15%、10.46%和10.58%。引入的SiC_(w)通过偏折裂纹、拔出和折断等方式起到了对复合陶瓷材料的增强增韧作用。
Silicon carbide (SiC) ceramic has a broad application prospect in aerospace and nuclear power industries due to its advantages of high strength,high hardness and low density.However,the processing difficulty and low toughness of SiC hinder its application.To solve the problems above,SiC_w/SiC composites containing different silicon carbide whiskers (SiC_w) were prepared via binder jetting additive manufacturing and liquid silicon infiltration.The experimental results show that the flexural strength and fracture toughness of the composite can be 215.29 MPa and 3.25 MPa·m~(1/2) when SiC_(w) contentis 7.5%(in volume fraction),and the hardness is 23.06 HV at 5%SiC_w.However,the residual silicon phase content within the composite elevates,and the mechanical properties deteriorates when SiC_(w) content further increases.The two carbonization processes to the green parts effectively reduce Si phase content and increase the flexural strength,fracture toughness,and hardness by 10.15%,10.46%,and10.58%,respectively.SiC_(w) is added as a reinforcing and toughening agent for the composite ceramic via deflection cracking,pulling out and fracturing.
作者
胡时东
冯琨皓
王启航
袁嘉明
毛贻桅
蔡道生
魏青松
HU Shidong;FENG Kunhao;WANG Qihang;YUAN Jiaming;MAO Yiwei;CAI Daosheng;WEI Qingsong(State Key Laboratory of Material Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2023年第12期3159-3168,共10页
Journal of The Chinese Ceramic Society
基金
武汉市科技项目(2020010602012037)
湖北省重点研发项目(2020BAB049)。
关键词
黏结剂喷射
碳化硅
碳化硅晶须
液硅反应熔渗
断裂韧性
增材制造
binder jetting
silicon carbide
silicon carbide whisker
reaction sintering
fracture toughness
additive manufacturing
