Abstract：Using α-Si3N4 as raw powder and MgO-Y2O3-Re2O3 as sintering assistant, Si3N4 ceramics were prepared by hot-pressing sintering, and the density, phase composition, microstructure, thermal conductivity, bending strength and fracture toughness of Si3N4 were tested by archimedean drainage method, XRD, SEM, laser flash method, three-point bending method and indentation method. Studies show that in samples with MgO-Y2O3-Re2O3 (Re=Er, Sm, Dy, La, Y, Yb) added, Sm2O3 , Y2O3 ,Yb2O3 are easy to facilitate Y2O3 to form the second phase Y2SiO3 , Y2Si3O3N4 and Y2SiO5 , respectively. Meanwhile, in the Si3N4 with MgO-Y2O3-Re2O3 (Re=Sm, Dy, La,Yb) added, the long columnar crystals are uniformly embedded in the smaller matrix grains, with self-strengthening and toughening. The bending strength is above 920 MPa, and the fracture toughness of indentation is above 6.93 MPa∙m1/2. Compared with traditional binary sintering assistant MgO-Re2O3, MgO-Y2O3-Re2O3 ternary additive has no regular influence on the microstructure, bending strength and fracture toughness of Si3N4 ceramics with the change of Re3+ radius, but its thermal conductivity increases with the decrease of Re3+ radius.
鲁欣欣, 刘伟, 李林, 李建斌. MgO-Y2O3-Re2O3添加对氮化硅陶瓷微观组织及性能的影响[J]. 粉末冶金材料科学与工程, 2019, 24(6): 536-541.
LU Xinxin, LIU Wei, LI Lin, LI Jianbin. Effects of MgO-Y2O3-Re2O3 on microstructure and properties of Si3N4 ceramics. Materials Science and Engineering of Powder Metallurgy, 2019, 24(6): 536-541.
[1] BECHER P F.Microstructural design of toughened ceramics[J]. Journal of American Ceramic Society, 1991, 74(2): 255-269. [2] 蒋强国. 含三元烧结助剂氮化硅陶瓷的制备、微观结构及性能研究[D]. 广州: 广东工业大学, 2015: 1-108. JIANG Qiangguo.Preparation, microstructure and properties of silicon nitride ceramics containing ternary sintering assistant[D]. Guangzhou: Guangdong University of Technology, 2015: 1-108. [3] BECHER P F, PAINTER G S, SHIBATA N, et al.Effects of rare-earth (RE) intergranular adsorption on the phase transformation, microstructure evolution, and mechanical properties in silicon nitride with RE2O3+MgO Additives: RE=La, Gd, and Lu[J]. Journal of the American Ceramic Society, 2010, 91(7): 2328-2336. [4] LI Y X, HAN W B, Chen G Q, et al.Influence of CeO2 addition on Si3N4 ceramics[J]. Materials Research Innovations, 2015, 19(S1): 339-342. [5] 段于森, 张景贤, 李晓光, 等. 稀土氧化物对常压烧结氮化硅陶瓷性能的影响[J]. 无机材料学报, 2017(12): 46-50. DUAN Yusen, ZHANG Jingxian, LI Xiaoguang, et al.Effect of rare earth oxides on the properties of silicon nitride ceramics sintered at atmospheric pressure[J]. Journal of Inorganic Materials, 2017(12): 46-50. [6] DOW H S, KIM W S, LEE J W.Thermal and electrical properties of silicon nitride substrates[J]. AIP Advances, 2017, 7(9): 1207-1212. [7] YANG Chunping, DING Junjie, MA Jie, et al.Microstructure tailoring of high thermal conductive silicon nitride through addition of nuclei with spark plasma sintering and post-sintering heat treatment[J]. Journal of Alloys and Compounds, 2019, 785(1): 89-95. [8] WILLS R R, HOLMQUIST S, WIMMER J M, et al.Phase relationships in the system Si3N4-Y2O3-SiO2[J]. Journal of Materials Science, 1976, 11(7): 1305-1309. [9] BECHER P F, SHIBATA N, PAINTER G S, et al.Observations on the influence of secondary Me oxide additives (Me=Si, Al, Mg) on the microstructural evolution and mechanical behavior of silicon nitride ceramics containing RE2O3 (RE=La, Gd, Lu)[J]. Journal of the American Ceramic Society, 2010, 93(2): 570-580. [10] 李勇霞. 高热导Si3N4基复合材料的制备与性能研究[D]. 哈尔滨: 哈尔滨工业大学, 2018: 1-103. LI Yongxia.Preparation and properties of high thermal conductivity Si3N4 matrix composites[D]. Harbin: Harbin Institute of Technology, 2018: 1-103. [11] 蒋强国, 古尚贤, 周茂鹏, 等. MgO-Lu2O3-Re2O3三元添加剂对氮化硅陶瓷性能的影响[J]. 陶瓷学报, 2015, 36(5): 459-463. JIANG Qiangguo, GU Shangxian, ZHOU Maopeng, et al.Effects of MgO-Lu2O3-Re2O3 ternary additives on the properties of silicon nitride ceramics[J]. Journal of Ceramics, 2015, 36(5): 459-463. [12] 谢娇娇, 艾江. 烧结助剂(Y2O3、Al2O3、La2O3)对β-Si3N4自增韧陶瓷的性能研究[J]. 陶瓷, 2017, 1(9): 37-43. XIE Jiaojiao, AI Jiang.Study on properties of β-Si3N4 self-toughened ceramics with sintering aids(Y2O3, Al2O3, La2O3)[J]. Ceramics, 2017, 1(9): 37-43. [13] TATARKO P, STEFANIA L, DUSZA J, et al.Influence of Various rare-earth oxide additives on microstructure and mechanical properties of silicon nitride based nanocomposites[J]. Materials Science & Engineering A, 2010, 527(18/19): 4771-4778. [14] BECHER P F, PAINTER G S, SUN E Y, et al.The importance of amorphous intergranular films in self-reinforced Si3N4 ceramics[J]. Acta Materialia, 2000, 48(18/19): 4493-4499. [15] WANG Z H, BAI B, NING X S.Effect of rare earth additives on properties of silicon nitride ceramics[J]. Advances in Applied Ceramics, 2014, 113(3): 173-177. [16] WEI L, TONG W, HE R, et al.Effect of the Y2O3 additive concentration on the properties of a silicon nitride ceramic substrate[J]. Ceramics International, 2016, 42(16): 18641-18647. [17] YOU Z, HUDEKI H, DAI K, et al.Effects of yttria and magnesia on densification and thermal conductivity of sintered reaction-bonded silicon nitrides[J]. Journal of the American Ceramic Society, 2018, 102(4): 1579-1588.
2019, Vol. 24 
