氧化物与碳化物增强钨基复合材料的制备及性能研究

发布时间：2018-01-19 02:40

  本文关键词： W-Y_2O_3复合材料 W-TiC-Y_2O_3复合材料 湿化学法 热机械法 放电等离子烧结 氦离子辐照 热负荷行为　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：钨因为具有高熔点、热导性好、高温强度下能保持较高的强度等优点,成为最具发展前景的面向等离子体第一壁候选材料。但钨存在低温脆性、再结晶脆性、辐照脆化和辐照损伤等问题,通过向钨中添加第二相粒子,如Y_2O_3和TiC可以增强钨基材料高温和室温力学性能和抗辐照性能。本文首先选择湿化学法结合SPS制备了W-4vol%Y_2O_3复合材料,探究了粉末的最佳还原工艺,并研究了W-4vol%Y_2O_3块体材料的烧结性能及抗热冲击、氦辐照性能。然后采用湿化学法制备了W-(4/8/12)vol%TiC-4vol%Y_2O_3系复合材料,探究了TiC含量对W-TiC-Y_2O_3复合材料显微组织和性能影响。最后,提出热机械法制备钨基复合材料新工艺,并将热机械法制备的W-12vol%TiC-4vol%Y_2O_3复合材料与湿化学法进行抗热冲击和氘滞留性能对比。主要研究结果如下:(1)采用湿化学法制备W-4vol%Y_2O_3复合材料时,当还原温度为800℃、时间为1h时,前驱体粉末最佳的还原氢气流速为600ml/min,其粒度最小,约200nm左右,且均匀性最好。(2)制备的W-4vol%Y_2O_3复合材料进行不同能量热冲击试验,随着激光束热通量增加,材料表面的钨及Y_2O_3被熔化,材料内部发生再结晶并产生裂纹。氦辐照后,基体表面生成纳米级絮状绒毛,Y_2O_3表面仅粗糙化,表现出更好的抗辐照性。(3)采用湿化学法在添加Y_2O_3基础上,向钨中添加TiC,发现随着TiC含量的增加,W-TiC-Y_2O_3材料的致密度和硬度增加,晶粒逐渐细化,其中W-12vol%TiC-4vol%Y_2O_3复合材料晶粒最小,约5μm,且其第二相既分布在晶界,也分布在晶内。(4)采用热机械法制备的W-12vol%Ti C-4vol%Y_2O_3复合材料与湿化学法相比,致密度和硬度较高,晶粒更细小,材料强度更高。分析微观成分,材料内部生成氧化物Y_2(Ti_2O_7)和固溶体(W,Ti)C_(1-x)。分析两种工艺制备的复合材料激光热冲击后的形貌以及辐照后的氘滞留数据,结果表明热机械法制备的W-TiC-Y_2O_3复合材料具有更好的抗热冲击和抗辐照性能。
[Abstract]:Because of the advantages of high melting point, good thermal conductivity and high strength at high temperature, tungsten is the most promising candidate material for plasma first wall, but tungsten has low temperature brittleness and recrystallization brittleness. The problems of irradiation embrittlement and radiation damage were studied by adding the second phase particles to the tungsten. For example, Yak _ 2O _ 3 and TiC can enhance the mechanical properties and radiation resistance of tungsten based materials at high temperature and room temperature. In this paper, W-4volo _ 3 / Y _ 2O _ 3 composites were prepared by wet chemical method combined with SPS. . The optimum process of powder reduction was studied, and the sintering properties and thermal shock resistance of W-4vol-Ys _ 2O _ 3 bulk material were studied. Radiation properties of helium. W-Li / 4 / 8 / 12 TiC-4volr / Ys / 22O3 composite materials were then prepared by wet chemical method. The effect of TiC content on the microstructure and properties of W-TiC-Y _ W _ 2O _ 3 composite was investigated. Finally, a new technology of preparing tungsten matrix composites by thermo-mechanical method was proposed. The thermal shock resistance and deuterium retention of W-12volum TiC-4vol3 composite prepared by thermomechanical method were compared with those of wet chemical method. The main results are as follows: 1). W-4volr / Y _ 2O _ 3 composite was prepared by wet chemical method. When the reduction temperature is 800 鈩，

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