本文以不同粒度的碳化硼粉末为原料,采用热压烧结方法制备碳化硼陶瓷,并通过X射线衍射仪、扫描电子显微镜、显微硬度计和万能力学试验机等研究原料粉末粒度和烧结工艺参数对碳化硼陶瓷显微组织和力学性能的影响。结果表明：碳化硼陶瓷的孔隙率和晶粒尺寸随粉末粒度降低不断减小,但晶粒尺寸增大率不断增加。烧结温度的提高、烧结压力的增加和保温时间的延长均有利于促进碳化硼陶瓷的致密化。碳化硼陶瓷的力学性能受孔隙率和晶粒尺寸的影响,当孔隙率由13.49%降低至0.31%时,显微硬度由15.1 GPa提高至31.7 GPa,断裂韧性由3.04 MPa·m1/2降低至2.07 MPa·m1/2;当平均晶粒尺寸由1.47 μm增大至150.51 μm时,显微硬度由31.3 GPa降低至28.9 GPa,断裂韧性由2.55 MPa·m1/2降低至1.42 MPa·m1/2。
In this paper, boron carbide ceramics were prepared by hot press sintering method using boron carbide powders of different particle sizes as raw materials. The effects of the raw material powder particle size and sintering process parameters on the microstructure and mechanical properties of boron carbide ceramics were investigated using X-ray diffractometer, scanning electron microscope, microhardness tester, and universal mechanical testing machine. The results show that the porosity and grain size of boron carbide continuously decrease with the reduction of powder particle size, while the grain growth rate accelerates. The increase in sintering temperature, the enhancement of sintering pressure, and the extension of soaking time are conducive to promoting the densification of boron carbide ceramics. The mechanical properties of boron carbide ceramics depend on the porosity and grain size. As the porosity decreases from 13.49% to 0.31%, the microhardness increases from 15.1 GPa to 31.7 GPa, while the fracture toughness decreases from 3.04 MPa·m1/2 to 2.07 MPa·m1/2. As the average grain size increases from 1.47 μm to 150.51 μm, the microhardness decreases from 31.3 GPa to 28.9 GPa, while the fracture toughness decreases from 2.55 MPa·m1/2 to 1.42 MPa·m1/2.
[1] MOSHTAGHIOUN B M, ORTIZ A L, GÓMEZ-GARCÍA D, et al. Densification of B4C nanopowder with nanograin retention by spark-plasma sintering[J]. Journal of the European Ceramic Society, 2015, 35(6): 1991-1998.
[2] SURI A K, SUBRAMANIAN C, SONBER J K, et al.Synthesis and consolidation of boron carbide: a review[J]. International Materials Reviews, 2010, 55(1): 4-40.
[3] 王京锋, 刘景林, 许卫刚. 动压气体轴承陀螺电机技术发展综述[J]. 微电机, 2016, 49(3): 90-94.
WANG Jingfeng, LIU Jinglin, XU Weigang.Development and application of technology of dynamic hydrodynamic gas bearing gyroscope motor[J]. Micromotors, 2016, 49(3): 90-94.
[4] JI W, REHMAN S S, WANG W M, et al.Sintering boron carbide ceramics without grain growth by plastic deformation as the dominant densification mechanism[J]. Scientific Reports, 2015, 5: 15827.
[5] MORADKHANI A, BAHARVANDI H, SAMANI M M M. Mechanical properties and microstructure of B4C-NanoTiB2-Fe/Ni composites under different sintering temperatures[J]. Materials Science and Engineering A, 2016, 665: 141-153.
[6] ZHANG X R, GAO H J, ZHANG Z X, et al.Effects of pressure on densification behaviour, microstructures and mechanical properties of boron carbide ceramics fabricated by hot pressing[J]. Ceramics International, 2017, 43(8): 6345-6352.
[7] GOSSET D.Basic properties of boron carbide[M]//KONINGS R J M, STOLLER R E. Comprehensive Nuclear Materials. Amsterdam: Elsevier, 2020: 539-553.
[8] MOSHTAGHIOUN B M, CUMBRERA F L, ORTIZ A L, et al.Additive-free superhard B4C with ultrafine-grained dense microstructures[J]. Journal of the European Ceramic Society, 2014, 34(3): 841-848.
[9] MATOVIĆ B, URBANOVICH V, GIRMAN V, et al.Densification of boron carbide under high pressure[J]. Materials Letters, 2022, 314: 131877.
[10] DU X W, ZHANG Z X, WANG Y, et al.Hot-pressing kinetics and densification mechanisms of boron carbide[J]. Journal of the American Ceramic Society, 2015, 98(5): 1400-1406.
[11] CHAIM R, SHLAYER A, ESTOURNES C.Densification of nanocrystalline Y2O3 ceramic powder by spark plasma sintering[J]. Journal of the European Ceramic Society, 2009, 29(1): 91-98.
[12] 史秀梅, 崔红, 曹剑武, 等. Al2O3/Y2O3复合助剂对常压烧结B4C陶瓷性能的影响[J]. 兵器材料科学与工程, 2017, 40(1): 62-66.
SHI Xiumei, CUI Hong, CAO Jianwu, et al.Effect of Al2O3/Y2O3 on properties of B4C ceramics prepared by pressureless sintering[J]. Ordnance Material Science and Engineering, 2017, 40(1): 62-66.
[13] YE K C, PRIKHNA T, HU C P, et al.Morphology characteristics and mechanical properties of hot-pressed micron/sub-micron boron carbide ceramics[J]. Materials Today Communications, 2021, 29: 102751.
[14] YANG M S, ZHUANG Y X, XING P F.High-performance B4C-LaB6 composite ceramics fabricated via hot-pressing sintering with La2O3 as sintering additive[J]. Ceramics International, 2021, 47(23): 32675-32684.
[15] 徐志伟, 彭可, 袁铁锤. 快速热压烧结制备高性能B4C-LaB6复合陶瓷[J]. 粉末冶金材料科学与工程, 2024, 29(1): 35-44.
XU Zhiwei, PENG Ke, YUAN Tiechui.High-performance B4C-LaB6 composite ceramics fabricated via rapid hot press sintering[J]. Materials Science and Engineering of Powder Metallurgy, 2024, 29(1): 35-44.
[16] 徐学军, 徐志伟, 袁铁锤, 等. 添加Al-Mg-Sc-Zr合金对热压烧结碳化硼组织及性能的影响[J]. 粉末冶金材料科学与工程, 2023, 28(6): 587-595.
XU Xuejun, XU Zhiwei, YUAN Tiechui, et al.Effects of adding Al-Mg-Sc-Zr alloy on microstructure and properties of boron carbide prepared by hot press sintering[J]. Materials Science and Engineering of Powder Metallurgy, 2023, 28(6): 587-595.
[17] MOSHTAGHIOUN B M, GOMEZ-GARCIA D, DOMINGUEZ-RODRIGUEZ A, et al.Grain size dependence of hardness and fracture toughness in pure near fully-dense boron carbide ceramics[J]. Journal of the European Ceramic Society, 2016, 36(7): 1829-1834.
