【作者】 彭可武； 吴文远； 徐璟玉； 孙树臣； 涂赣峰；

【Author】 Peng Kewu, Wu Wenyuan, Xu Jingyu, Sun Shuchen, Tu Ganfeng (School of Material and Metallurgy , Northeastern University, Shenyang 110004 , China)

【机构】 东北大学材料与冶金学院；

【摘要】 对热压烧结法制备的B4C-LaB6材料进行了性能测试。研究结果表明:随LaB6的加入,热压烧结B4C-LaB6材料的硬度增加,当添加量为6％时,其硬度比单一B4C材料的硬度提高了20．52％,达到了最大值31．83 GPa;总的说来,LaB6添加量对热压烧结B4C-LaB6材料的抗弯强度影响不大;LaB6添加量对热压烧结B4C-LaB6材料的断裂韧性影响较大,随着硼化镧添加量的增加呈成锯齿波变化。当硼化镧添加量为 6％的时候,断裂韧性达到最大值5．14．MPa·m1／2,比单一碳化硼提高了39．67％。LaB6-B4C材料的断口经电镜扫描分析后发现:LaB6的加入改变了单一B4C材料的烧结状态,使其晶粒间排列致密,孔隙减少;B4C-LaB6材料断裂方式主要是以沿晶断裂为主,穿晶断裂所占的比例变得很小,这与陶瓷材料断裂韧性提高机制相一致。更多还原

【Abstract】 The properties of boron carbide-lanthanum boride composite material prepared by hot pressed sintering method was tested, and lanthanum boride as a sintering aid for boron carbide was investigated. The resut shows that the hardness of boron carbide-lanthanum boride increases with the amount of lanthanum boride. When the amount of the lanthanum boride is 6% , the hardness reaches its supreme value of 31.83 GPa, its hardness is improved nearly 20.52% compared to single phase boron carbide. The adding amount of the lanthanum boride has little effect on flexibility strength. However, it gives much effect on fracture toughness. The fracture toughness changes like the form of saw-toothed wave as the amount of lanthanum boride increases in the test. When the amount of the lanthanum boride is 6% , the fracture toughness reaches its supreme value of 5.14 MPa·m1/2, which is improved nearly 39.67% compared to single phase boron carbide materials. The fracture scanning electric microscope analysis of boron carbide-lanthanum boride composite material finds that, with the increasing the amount of lanthanum boride, the interior station of pure boron carbide is changed. The crystallite arrangement is so compact that pores disappear gradually. The main fracture way of boron carbide-lanthanum boride composite material is intercrystalline rupture, while the transcrystalline rupture is minor, which is in accordance with fracture mechanism of boron carbide .更多还原