Fluidization limit and slip structure in aqueous concentrated slurry containing hydrophobic hetero-particles in the presence of polymer-dispersant

聚合物分散剂存在下含有疏水杂颗粒的水性浓缩浆料的流化极限和滑移结构

基本信息

批准号：
11450334
负责人：
HASHIBA Minoru
金额：
$ 9.41万
依托单位：
Gifu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

The SiC powders were pre-heated to evaluate the effect of the amount of free carbon and oxygen content on the surface of the SiC particles on the fluidity of the SiC slurries and the sintered density. Heating of the SiC powders at over 300℃ enhances the fluidity of the SiC slurries. The fluidity of C slurries was effectively enhanced by the addition of ammonium 2-naphthalene sulfonate formaldehyde condensate ( DEMOL-AS ) solution, compared with the addition of styrene/maleic copolymer ( SM ) solution with tetramethyl ammonium hydroxide ( TMAOH ) at pH 10-1 1. The SiC slurries with C and B_4C as sintering aids were prepared by controlling a pH of 10-11 with TMAOH and adding the optimum amount ofDEMOL-AS or SM to C content and then slip casting was conducted. The sintered body containing the SiC powders pre-heated at any temperatures was achieved the higher density of about 98 % Th. D. The SiC body of higher sintered density was possible to fabricate by controlling the addition of carbon, taking into account oxygen content on the surface of the SiC particles and the amount of free carbon.Zirconium acetate effectively enhanced the dispersion and fluidity of SiC slurries in the weakly acidic pH range. The optimum pH valuetod concentration of Zr-A for the SiC slurries were pH 3.5 and 0.5-1 wt % of the SiC, respectively. In aqueous media, Zr-A became a positively charged species. The SiC particles also exhibited a positively charged state at pH 3.5. Thus, the role of Zr-A in the dispersion of slurries should be interpreted as that of a depletion-stabilization mechanism.

对SiC粉末进行预热，评价SiC颗粒表面游离碳含量和氧含量对SiC浆料流动性的影响，并在300℃以上加热SiC粉末，提高了烧结密度。 SiC浆料的流动性通过添加2-萘磺酸铵甲醛缩合物有效增强了C浆料的流动性。 DEMOL-AS ) 溶液，与在 pH 10-1 下添加苯乙烯/马来酸共聚物 ( SM ) 溶液和四甲基氢氧化铵 ( TMAOH ) 进行比较 1. 通过控制 pH 值来制备以 C 和 B_4C 作为烧结助剂的 SiC 浆料10-11用TMAOH并添加最佳量的DEMOL-AS或SM至C含量，然后进行注浆成型烧结体。含有在任何温度下预热的 SiC 粉末的材料都获得了约 98% D 的较高密度。通过控制碳的添加量并考虑到表面的氧含量，可以制造更高烧结密度的 SiC 体。醋酸锆在弱酸性pH范围内有效增强了SiC浆料的分散性和流动性，确定了Zr-A的最佳pH值。 SiC 浆料的 pH 值分别为 3.5 和 0.5-1 wt%。在水介质中，Zr-A 变成带正电的物质。SiC 颗粒在 pH 3.5 时也表现出带正电的状态。浆料分散中的 A 应被解释为耗尽稳定机制的 A。