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用Gd_2O_3和B_4C制备GdB_6过程中的化学反应

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东北大学学报（自然科学版） 2006年第3期27卷 288-291页

作者：吴文远徐璟玉孙树臣涂赣峰东北大学材料与冶金学院辽宁沈阳110004

研究了Gd2O3与B4C在碳管炉中，Ar气氛下制备GdB6过程中的化学反应．XRD和TG-DTA实验研究结果表明：在367～458℃期间，主要是样品中残留的杂质C和O2发生反应；800～1200℃时，Gd2O3与B4C生成GdBO3，GdBC和B；并同时存在GdBO3，GdBC与B4... 详细信息

研究了Gd2O3与B4C在碳管炉中，Ar气氛下制备GdB6过程中的化学反应．XRD和TG-DTA实验研究结果表明：在367～458℃期间，主要是样品中残留的杂质C和O2发生反应；800～1200℃时，Gd2O3与B4C生成GdBO3，GdBC和B；并同时存在GdBO3，GdBC与B4C生成GdB4；Gd2O3与B4C生成GdB6．随温度升高，GdB4生成反应速度加快．1470℃时，GdB4和B反应生成GdB6，GdB6的生成率随反应时间延长而增加，6h时生成率达到了97．8％．

关键词：化学反应硼化钆碳化硼氧化钆:XRD TG-DTA

High Temperature Chemical Reaction of La_2O_3 in H_3BO_3-C System

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Journal of Rare Earths 2007年第3期25卷 282-285页

作者：吴文远徐璟玉彭可武涂赣峰 School of Material and Metallurgy Northeastern University

The high temperature chemical reaction process of La2O3 in H3BO3-C system was studied by means of XRD and *** results showed that dehydration reaction of H3BO3 occurred in the temperature range of 82～390 ℃;La2O3 and B2O3 reacted to form LaB3O6,LaBO3,and B4C in the temperature range of 836～1400℃;at 1450 ℃,B4C and LaBO3 further reacted to form LaB4,and partial LaB4 and B reacted to form LaB6;at 1500 ℃,LaB4 and B reacting into LaB6 was the main reaction,and the content of LaB6 increased with prolonging time.

关键词： high temperature chemical reaction lanthanum boride boric acid-carbon lanthanum oxide rare earths

B_4C/Al复合材料力学性能及其断裂机理的研究

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热加工工艺 2007年第4期36卷 1-3,37页

作者：彭可武吴文远徐璟玉涂赣峰东北大学材料与冶金学院辽宁沈阳110004

对无压浸渗法制备的B4C/Al复合材料进行了力学性能测试。结果表明,B4C/Al复合材料的抗弯强度和断裂韧性与单一B4C材料相比有显著提高。B4C/Al复合材料的抗弯强度及断裂韧性分别比单一B4C提高了18.39%和75.27%,但其硬度降低。B4C/Al复合... 详细信息

对无压浸渗法制备的B4C/Al复合材料进行了力学性能测试。结果表明,B4C/Al复合材料的抗弯强度和断裂韧性与单一B4C材料相比有显著提高。B4C/Al复合材料的抗弯强度及断裂韧性分别比单一B4C提高了18.39%和75.27%,但其硬度降低。B4C/Al复合材料经扫描电镜和背散射仪分析后发现,无压浸渗法制备的B4C/Al复合材料中没有大尺寸的显微缺陷,组织分布比较均匀、致密;B4C以连续的骨架结构存在,而渗入的铝相也以连续基体的形式存在;单一B4C存在较多的穿晶断裂,而B4C/Al复合材料的断裂方式主要以沿晶断裂为主,这是B4C/Al复合材料断裂韧性提高的主要原因。

关键词： B4C/A1复合材料碳化硼无压浸渗力学性能断裂方式

GdB_6对热压烧结B_4C材料性能的影响

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稀土 2005年第4期26卷 10-14页

作者：徐璟玉吴文远边雪孙树臣涂赣峰东北大学材料与冶金学院辽宁沈阳110004

对热压烧结法制备的B4C-GdB6材料进行了性能测试.结果表明:在GdB6添加量为2%～8%的范围内,随其添加量的增加,B4C-GdB6材料的硬度增加,比单一B4C材料增加了78%;抗弯强度降低;断裂韧性先减小后增大,但变化不大.B4C-GdB6材料的断口扫描电... 详细信息

对热压烧结法制备的B4C-GdB6材料进行了性能测试.结果表明:在GdB6添加量为2%～8%的范围内,随其添加量的增加,B4C-GdB6材料的硬度增加,比单一B4C材料增加了78%;抗弯强度降低;断裂韧性先减小后增大,但变化不大.B4C-GdB6材料的断口扫描电镜分析发现,GdB6的加入改变了单一B4C材料的烧结状态,随添加量的增加,B4C晶粒显著增大,晶粒间排列致密,使孔隙逐渐消失.

关键词：硼化钆碳化硼热压烧结性能

Mechanical Properties and Fracture Mechanism of Boron Carbide-Lanthanum Boride Composite

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Journal of Rare Earths 2005年第S1期23卷 387-391页

作者：彭可武吴文远徐璟玉孙树臣涂赣峰 School of Material and Metallurgy Northeastern University Shenyang 110004 China

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 result shows that the hardness of boron carbide-lanthanum boride increases with the increasing content of lanthanum boride. When the content of the lanthanum boride is 6%, the hardness reaches its supreme value of 31.83 GPa, and its hardness is improved nearly 20.52% compared to monolithic boron carbide. The content of the lanthanum boride does not greatly affect flexibility strength, however, it gives much effect on fracture toughness. The curve of fracture toughness likes the form of saw-toothed wave as the content of lanthanum boride increases in the test. When the content of the lanthanum boride is 6%, the fracture toughness reaches its supreme value of 5.14 MPa·m 1/2, which is improved nearly 39.67% compared with monolithic boron carbide materials. The fracture scanning electric microscope analysis of boron carbide-lanthanum boride composite material shows that, with the increase of the content of lanthanum boride, the interior station of monolithic 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 ceramic material. It indicates that this change of fracture mode by the addition of lanthanum boride gives rise to the improvement of the fracture toughness.

关键词： lanthanum boride boron carbide fracture mechanism mechanical properties

Phase Constitution in Mixed Gd_2O_3 and B_4C by Sintering at High Temperature

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Journal of Rare Earths 2005年第3期23卷 345-348页

作者：吴文远徐璟玉边雪胡广勇孙树臣涂赣峰 School of Material and Metallurgy Northeastern University Shenyang 110004 China

The phase constitution in mixed Gd2O3 and B4C by sintering in graphite tube furnace at the temperature of 100～1489 ℃ in argon atmosphere was studied by means of XRD and TG-DTA. The results show that the impurity C reacts with O in the B4C at the temperature of 367～458 ℃. When the temperature is 800 ℃, Gd2O3 reacts with B4C, and the reaction products include GdB6, GdB4, GdBO3, GdBC and B. GdBC changes into GdB4 at 1200 ℃. When the temperature is 1470 ℃, GdB6 is obtained by the reaction of GdB4 with elemental B. The content of GdB6 is increasing with the prolonging time.

关键词： high temperature sintering phase constitution gadolinium boride boron carbide gadolinium oxide rare earths

退火处理对B_4C-CeB_6/Al复合材料相组成及其力学性能的影响

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热加工工艺 2007年第18期36卷 38-41页

作者：彭可武吴文远徐璟玉宁福虎涂赣峰东北大学材料与冶金学院辽宁沈阳110004

首次向B4C中添加CeO2,原位合成制备了B4C-CeB6多孔增强体。然后采用无压浸渗法,将金属铝渗入B4C-CeB6增强体中,制备出B4C-CeB6/Al复合材料,对其进行了相组成的分析和力学性能的测试。对无压浸渗法制备的B4C-CeB6/Al复合材料进行不同温... 详细信息

首次向B4C中添加CeO2,原位合成制备了B4C-CeB6多孔增强体。然后采用无压浸渗法,将金属铝渗入B4C-CeB6增强体中,制备出B4C-CeB6/Al复合材料,对其进行了相组成的分析和力学性能的测试。对无压浸渗法制备的B4C-CeB6/Al复合材料进行不同温度下的退火处理后,对其也进行了相组成的分析和力学性能的测试。结果表明,在本试验的退火温度下,退火后的B4C-CeB6/Al复合材料的抗弯强度相比未退火的有显著提高;而退火后的B4C-CeB6/Al复合材料的断裂韧性略有提高;退火处理对复合材料硬度几乎没有影响。将未退火的B4C-CeB6/Al复合材料和退火处理后的B4C-CeB6/Al复合材料都用XRD检测其中的相组成,发现其中相组成无变化,但是复合材料中各相的含量变化却各不相同。

关键词： B4C-CeB6/Al复合材料原位反应退火处理力学性能相组成

CeO2-B4C-C体系的高温化学反应及相组成研究

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稀土 2008年第5期29卷 10-13页

作者：徐璟玉吴文远边雪涂赣峰李学舜杨国胜东北大学材料与冶金学院辽宁沈阳110004 包头天骄清美稀土抛光粉有限公司内蒙古包头014010

采用XRD和TG-DTA方法对CeO2-B4C-C体系的高温化学反应及相组成进行了研究。结果表明,650℃-910℃时,CeO2同B4C生成CeBO3、CeBC和B;1270℃-1309℃时,CeO2同B4C生成CeBO3、B和CeB4,以及Ce-BO3、CeBC和B4C生成CeB4;在以上两个温度区间内,碳的作用很小。1317℃-1370℃时,CeBO3、B4C和C生成CeB4和B;1371℃-1420℃时,CeO2、B4C和C生成CeB6和CO;在以上两个温度区间内,碳的作用显著。1460℃的高温下,CeB4和B进一步反应生成CeB6,此时CeB6相占主要地位,其生成率随反应时间延长而增加。

关键词：高温化学反应相组成硼化铈碳化硼氧化铈

Study of the Performance and Microstructure of CeB_6/B_4C Ceramic Composite via in-situ Synthesis

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Journal of Rare Earths 2007年第S1期25卷 468-472页

作者：徐璟玉吴文远彭可武宁福虎涂赣峰 School of Material and Metallurgy Northeastern University

CeB6/B4C ceramic composite was fabricated by hot-pressed sintering via in-situ synthesis reaction among B4C, CeOand C. The effects of CeB6 content on the performance and microstructure of CeB6/B4C composites were investigated. As the content of CeB6 was 2.42%, the microhardness of CeB6/B4C composite reached the maximum of 40.64 GPa, which was higher than that of monolithic B4C by 52.5%. As the content of CeB6 was 4.89%, the flexibility strength and the fracture toughness of CeB6/B4C composite reached the peak values of 346.7 MPa and 5.95 MPa·m1/2 respectively, which were higher than those of monolithic B4C by 17.96% and 61.7% respectively. The integrated mechanical property of CeB6/B4C ceramic composite with the 4.89% CeB6 content is optimal. It was also found that as in-situ synthesis of CeB6, the crystal grain growth was inhibited, and crystallite arrangement was so compact that the pores gradually reduced. The main fracture mode of CeB6/B4C ceramic composite was intercrystalline rupture, while the transcrystalline rupture was minor.

关键词： in-situ synthesis cerium boride boron carbide performance fracture mode rare earths