Chuang-Tian Zhan,Sheng-Jin He,Wei-Ming Guo,Yuan-Bin Chen,Shi-Kuan Sun,Hua-Tay Lin
Combined with the thickness control of interlayers (∼10 µm and ∼60 µm), SiC nano-powders with Al 2 O 3 -Y 2 O 3 -MgO-CaO additive (NITE-SiC) were used as the joining materials to achieve the low-temperature joining of SiC ceramics. Some residual pores were observed in the interlayer with a thickness of ∼60 µm after joining at 1650 ℃, and the shear strength of SiC joints measured was 39.3 ± 5.5 MPa. Observations showed the fracture of joints occurred at the interlayer. When the thickness of the interlayer decreased to ∼10 µm, no cracks or porosity were observed at the interface region after joining at 1650 ℃. The shear strength of SiC joints increased to 69.5 ± 8.9 MPa, and the fracture originated from the matrix. The results demonstrated using NITE-SiC with Al 2 O 3 -Y 2 O 3 -MgO-CaO additive as the joining layer and reducing the thickness of the interlayer could lower the joining temperature and significantly improve the mechanical strength of joints.
Zhiyuan Wang,Ce Zheng,Hongru Jin,Yichun Bi,Shengkai Wang,Xiaoqiang Li
This study investigates the densification, mechanical properties, and irradiation response of NITE-SiC fabricated using two low-content quaternary sintering additive systems: AlN-Y 2 O 3 -CeO 2 -MgO (AN-SiC) and Al 2 O 3 -Y 2 O 3 -CeO 2 -MgO (AO-SiC). The incorporation of nitrogen significantly enhances densification by increasing liquid phase viscosity, thereby suppressing additive evaporation and enabling >99.5 % relative density. Multi-cation doping (Y, Ce, Mg, Al) into the Y 2 Si 2 O 7 intergranular phase reduces eutectic temperature and promotes homogeneous sintering. Under irradiation to 7–8 dpa at 550–750 °C, both systems exhibit exceptional stability, attributed to the highly ionic Y 2 Si 2 O 7 structure resisting amorphization and accommodating dopants without segregation. Damage remains dominated by intragranular defect evolution in SiC grains, while AN-SiC demonstrates reduced radiation hardening and enhanced modulus recovery, highlighting the synergistic role of nitrogen in improving sintering and radiation resistance for Gen-IV reactor applications.
危险品化学品经营许可证（带存储）