【摘要】：ZrB2以其優(yōu)異的物理化學(xué)性能,如高熔點(diǎn)、高強(qiáng)度、良好的導(dǎo)電導(dǎo)熱性以及優(yōu)異的抗腐蝕性,近年來(lái)吸引了越來(lái)越多的關(guān)注。然而,由于其較高的體積密度(6.085g/cm3)和低的抗熱震性,也在一定程度上影響到了ZrB2的開(kāi)發(fā)應(yīng)用。輕質(zhì)、熱穩(wěn)定性好是多孔陶瓷兩個(gè)突出優(yōu)點(diǎn)。把ZrB2陶瓷設(shè)計(jì)成一種多孔結(jié)構(gòu)降低其體積密度并改善其抗熱震性能有效地解決上述問(wèn)題。本文以微米級(jí)ZrB2為原料,通過(guò)凝膠注模成型的方式成功制得了ZrB2多孔陶瓷。論文的主要內(nèi)容包括： (1)ZrB2料漿制備。研究結(jié)果表明,分散劑PAA和PEI更適合于用來(lái)分散ZrB2。 PAA做ZrB2粉體的分散劑時(shí),當(dāng)料漿pH值為9、添加2wt%的PAA,球磨12h后能夠獲得分散穩(wěn)定性很好的ZrB2料漿；以PEI為ZrB2粉體的分散劑時(shí),調(diào)節(jié)pH值為5、添加2wt%的PEI、球磨10h后同樣能夠獲得分散穩(wěn)定性很好的ZrB2料漿。 (2)ZrB2濕坯成型及干燥。研究結(jié)果表明,當(dāng)單體(AM)含量為4wt%時(shí),ZrB2陶瓷漿料不僅具有最低的粘度,料漿凝膠時(shí)間也能控制在10min左右；APS、 TEMED的添加量分別為0.02g/100g、0.03g/100g漿料,溫度為40℃時(shí),最有利于ZrB2陶瓷漿料的注凝操作。之后ZrB2陶瓷濕坯會(huì)先浸入液體干燥劑(無(wú)水乙醇)中,時(shí)間為24h,之后取出置于室溫下干燥10h,最后將生坯放入真空干燥箱(50℃)中干燥,這樣既能使?jié)衽骺焖俚拿撍稍镉帜鼙苊猱a(chǎn)生開(kāi)裂、變形等缺陷。而生坯的干燥收縮率也隨著固含量的增大而減小,當(dāng)生坯固含量小于35vo1%時(shí),生坯干燥過(guò)程中收縮較大,均大于10%。 (3)ZrB2多孔陶瓷的制備研究。研究發(fā)現(xiàn),燒結(jié)溫度、燒結(jié)助劑B4C的添加量、生坯固含量、保溫時(shí)間等參數(shù)都對(duì)ZrB2多孔陶瓷的性能有較大關(guān)系。在最佳工藝條件下,B4C添加量為6wt%,固含量為35vol%,在2050℃下燒結(jié)2h所得ZrB2多孔陶瓷的孔隙率為45.9%,抗壓強(qiáng)度達(dá)到最大值400MPa。
[Abstract]:ZrB2 has attracted more and more attention in recent years for its excellent physical and chemical properties, such as high melting point, high strength, good conductivity and thermal conductivity, and excellent corrosion resistance. However, due to its high volume density (6.085g/cm3) and low thermal shock resistance, it also affects the development and application of ZrB2 to a certain extent. Light weight and good thermal stability are two outstanding advantages of porous ceramics. The ZrB2 ceramic is designed as a porous structure to reduce its volume density and improve its thermal shock resistance to effectively solve the above problems. In this paper, ZrB2 porous ceramics were successfully prepared by gel injection molding using micrometer ZrB2 as raw material. The main contents of this paper are as follows: (1) preparation of ZrB2 slurry. The results show that the dispersants PAA and PEI are more suitable for dispersing ZrB2.. When PAA is used as dispersant of ZrB2 powder, the ZrB2 slurry with good dispersion stability can be obtained by adding 2 wt% PAA, ball mill for 12 h when the slurry pH is 9; When PEI is used as dispersant of ZrB2 powder, ZrB2 slurry with good dispersion stability can also be obtained by adjusting pH value to 5 and adding 2 wt% PEI, ball mill for 10 h. (2) ZrB2 wet billet forming and drying. The results show that when the monomer (AM) content is 4 wt%, the ZrB2 ceramic slurry not only has the lowest viscosity, but also can control the gelation time of the slurry to about 10min. When the addition of APS, TEMED is 0.02g / 100g and 0.03g / 100g respectively and the temperature is 40 鈩，

本文編號(hào)：2435203