陶瓷基复合材料胶态成形工艺研究进展

重点介绍了几种主要陶瓷基复合材料胶态成形工艺，包括注浆成形、注射成形、凝胶注模成形、直接凝固注模成形、温度诱导絮凝成形、水解辅助固化成形、电泳浇注成形和溶胶一凝胶法成形。对上述工艺的原理、工艺过程及特点进行了比较，并提出了陶瓷成形工艺的关键问题。     

铈盐引发卫生陶瓷直接凝固成形工艺的研究

采用凝胶注模成形方法，以丙烯酰胺为单体，硝酸铈铵为引发剂，研究了卫生陶瓷凝胶注模成形工艺，并探讨了不同工艺条件（单体加入量、引发剂加入量、减少剂加入量、坯体成形温度等因素）对料浆原位凝固成形脱模时间和坯体干燥强度的影响规律。     

高性能陶瓷原位凝固成型技术的研究进展

综述了高性能陶瓷原位凝固成型工艺的特点;重点介绍了近年来的四种陶瓷原位凝固成型方法,即注凝成型,直接凝固成型,温度诱导絮凝成型和胶态振动注模成型,并简要介绍了国内陶瓷原位凝固成型技术研究取得的新成果。     

陶瓷材料的胶态原位成型技术

生产成本高、稳定性低和可重现性差一直都是特种陶瓷材料商业化的主要障碍 ,理想的解决方法就是净尺寸成形技术 ,在成形大型复杂零件的同时仍能保证高的产品质量。近十年来 ,新发展起来的胶态原位成形技术因工艺设备简单 ,成本低廉 ,制品组分均匀 ,缺陷少 ,强度高 ,且易于成形复杂形状零件等优点 ,得到了国内外人士的关注 ,并已得到了大量的实际应用。[1～ 3 ] 它们是 :注射成形、直接凝固注模成形和注凝成形亦称凝胶注模成形。1　陶瓷的注射成形技术1.1　技术简介注射成形是将陶瓷粉料与热塑性树脂等有机物混练后得到混合料 ,在注射机上于…     

直接凝固注模成形制备Al2O3基陶瓷材料的研究

本文介绍了用直接凝固注模成形法制备Ａｌ２Ｏ３基陶瓷材料的基本工艺过程；研究了陶瓷浆料的固相含量，原位凝固剂等对材料性能的影响。结果表明，原位凝固剂可使浆料原位凝固，通过调节固相含量、凝固剂、缓冲剂可以控制凝固时间和陶瓷坯体强度；陶瓷坯体具有尺寸变化率小，密度较高且均匀，足够的脱模强度，表面质量好等特点。     

陶瓷材料成形工艺研究新进展

陶瓷制造经历了数千年的历史，当前阻碍陶瓷材料进一步发展的关键之一是成形工艺技术没有突破。笔者介绍了胶态成形、固体无模成形工艺及气态成形，对上述工艺的原理、工艺过程及特点进行比较，提出了陶瓷成形工艺的关键问题。并介绍了水基非塑性浆料的注射成形新工艺。     

硅溶胶、铝溶胶在陶瓷原位胶态成形中的应用

陶瓷原位胶态成形方法是制备近净尺寸复杂陶瓷部件最具应用前景的方法，硅溶胶、铝溶胶也越来越多的应用于其中。本文主要介绍了硅、铝溶胶的分散胶凝原理以及在胶态成形中的应用。     

基因及凝固注模成型Si3N4及SiC陶瓷：基本原理及工艺过程

直接凝固注模成型（ｄｉｒｅｃｔ ｃｏａｇｕｌａｔｉｏｎ ｃａｓｔｉｎｇ，ＤＣＣ）是一种崭新的（准）净尺寸陶瓷成型方法。本文了采用此法成ｉ３Ｎ４及ＳｉＣ陶瓷的基本原理和工艺过程，ＤＣＣ成型工艺过程为把高固相含量低粘度的陶瓷浆料浇注到无孔模具中，事先加入到浆料中的生物酶及化学物质通过改变浆料的ＰＨ或电解质浓度醚改变浆料的胶体化学行为，从而使浆料原位凝固，得到有足够脱模强陶瓷坯体。ＤＣＣ成型的特点为坯体     

陶瓷基复合材料胶态成型工艺研究进展

重点介绍了几种主要陶瓷基复合材料胶态成型工艺,包括注浆成型、注射成型、凝胶注模成型、直接凝固注模成型、温度诱导絮凝成型、水解辅助固化成型、电泳浇注成型和溶胶-凝胶法成型.对上述工艺的原理、工艺过程及特点进行了比较,并提出了陶瓷成型工艺的关键问题.     

凝胶注模成形技术的研究与发展

凝胶注模成形是一种近净尺寸成形工艺，是制备形状复杂、成分均匀和可靠性高的陶瓷材料的理想成形工艺。笔者阐述了凝胶注模成形工艺过程和成形原理，以及国内外的研究现状，指出了凝胶注模成形技术的未来发展方向。     

氧化锆陶瓷凝胶注模成形研究

试验采用高纯超细氧化锆粉伴为原料,通过凝胶注模成形工艺,获得氧化锆陶瓷刀具的坯体。参照已有经验,通过研究氧化锆陶瓷凝胶注模成形工艺流程及工艺参数与所得样品的关系,进行探索性试验。通过对比试验结果,获得最佳工艺参数,确定了氧化锆凝胶注模成形的最佳配方。按照试验提供的原料配方,严格控制干燥过程和烧成制度,可以得到结构致密、性能稳定、强度较高的陶瓷刀具,为凝胶注模成形方法的工业化推广提供了可靠的参考依据。     

Lattice-structured SiC ceramics obtained via 3D printing,gel casting,and gaseous silicon infiltration sintering

In view of technical difficulties in preparing ceramics with complex shapes, gel casting combined with 3D printing was here adopted to prepare silicon carbide ceramic green body, and gaseous silicon infiltration sintering was used to prepare 3D lattice-structured ceramics. The preparation of the slurry, gel curing, and ceramic molding was investigated. Results demonstrate that the ratio of components affects the fluidity and stability of slurry. However, when volume fraction of the solid phase of the slurry reaches 56%, the viscosity of slurry is only 300 mPa s, and drying shrinkage rate of green body is 6.6%; these characteristics make slurry suitable for 3D complex model injection molding. Furthermore, both the temperature and the initiator affect gel curing speed. As the temperature and initiator content increase, the induction and gel time are rapidly shortened. When demolding at 300 °C and when gaseous silicon infiltration sintering is carried out at 1550 °C, a 3D lattice-structured ceramic with relative density of 87% and average compressive strength of 433 MPa can be obtained.     

Rotary moulding of ceramic hollow wares

A novel processing method for the fast and economic production of hollow ceramic components has been developed by combining in situ coagulation moulding with a modified version of the technique of rotary moulding[Binner, J. G. P., Al-Dawery, I. A., Tari, G. and Yan, Y., Rotary casting technique. UK Patent application No. 0506349.0, March 2005], the latter being adapted from the polymer industry. The process was found to require a high solids content suspension, hence development work was performed in this direction though in the end a new, commercial suspension was utilised. Of the three forming routes of gel casting, direct coagulation casting and in situ coagulation moulding, the latter was found to be the most promising for the new process of rotary moulding of ceramics. Due to the low value of clay-based ceramics, a new low cost coagulant was identified and the effect of lactone concentration and temperature on setting time determined.Following substantial optimisation work, it was found that a two-speed approach to multi-axial rotation was the most successful; medium sized cream jugs could be produced in just 7 min. With respect to mould materials, the porous resin normally used for pressure casting of sanitary ware was found to be the best option, though since this is quite expensive conventional plaster-of-paris moulds were found to be a suitable material to enable companies, particularly SMEs, to become familiar with the technology whilst avoiding high costs for trials. The processed articles could be successfully fired and glazed using gas-fired kilns with no sign of any black cores.Major advantages of the process include the ability to precisely calculate the amount of ceramic slip required, eliminating either slip wastage or the need to pour used slip back into the virgin material as currently happens with slip casting. In addition, since the precursor suspension has a very high solids content, the time and energy required to dry the green product and associated moulds has been considerably reduced.     

离心技术在陶瓷材料制备中的应用

离心技术在金属材料的制备中已经有广泛的应用,然而对于陶瓷材料,由于其自身的特点和研究工作的欠缺,离心技术的应用至今还停留在实验室阶段。对离心技术在陶瓷材料制备中的研究现状进行了综述,着重介绍了离心注浆/铸造技术,并对当前离心技术在陶瓷材料制备中大规模应用所面临的问题提出了一些解决办法。     

Pressure filtration assisted gel casting in translucent alumina ceramics fabrication

High density and homogeneous green body is important for fabricating transparent ceramics. Inspired by the improved samples’ homogeneity in slip casting, we introduced low pressure filtration to gel casting to further increase the relative density and homogeneity of the green body and to shorten the drying time. The effect of pressure filtration on drying characteristics, bulk density and porosity of the pre-sintered bodies, and the microstructure and optical transmittance of the resultant ceramics were intensively investigated. The results showed that pressure filtration can reduce the drying time by 27.3%, improve the density of the pre-sintered bodies and reduce the residual pores of the sintered ceramics. The in-line transmittance of the translucent alumina prepared by the pressure filtration assisted gel casting was 32.7% at 600?nm with a thickness of 1?mm, which is about 6% higher than that without pressure filtration. In principle, this process can be applied to fabricate any other high-performance ceramic.     

氧化锆陶瓷注凝成型研究

本文对ZrO2注凝成型工艺中分散剂、固相体积含量对浆料流变性的影响进行了研究.研究表明分散剂的加入可以使浆料的Zeta电位值提高近40mv,浆料粘度降低;随固相体积含量增加,浆料粘度增加,但使浆料粘度降至最低所需分散剂的量减少.     

防护装甲用抗弹Al2O3陶瓷研究进展

抗弹Al₂O₃陶瓷因其高硬度、低密度以及低成本,在防护装甲领域占有重要地位。本文详尽综述了抗弹Al₂O₃陶瓷的生产原材料选择、制备技术及发展趋势,比较了干压成型、等静压成型、凝胶注模成型及粉末微注射成型技术,与常压烧结、热压烧结、热等静压烧结等烧结工艺对抗弹Al₂O₃陶瓷性能的影响,阐述了发展抗弹Al₂O₃透明陶瓷以满足当代军事需求、抗弹Al₂O₃陶瓷增韧化以克服其高脆性、低韧性的应用屏障,为抗弹Al₂O₃陶瓷的更多应用提供可能。     

Use of Kaolins from Different Deposits in the Production of Fine Ceramics

Data on the mineral, chemical, and granulometric compositions of Russian kaolins used in the production of fine ceramics are summarized. The possibilities of improving the quality of ceramic mixtures for molding and slip casting based on various kaolins are considered.     

Preparation and properties of fused silica ceramics by Isobam spontaneous coagulation casting

By surface modification with APTMS, spontaneous coagulation casting (SCC) of fused silica based on Isobam was achieved and the possible coagulation and molding mechanism is proposed. Through the interaction between the polar groups on the Isobam molecular chain and the incorporated –NH₂ groups on the surface of the silica particles, Isobam molecular chains were adsorbed on the surface of particles, which initiate the formation of flocs and the solidification of the suspension. The addition of dispersant TMAH results in the hydrolyzation of Isobam, forming more –COO^–, which effectively improves the fluidity and stability of the suspension. Then the zeta potential, rheological properties and coagulation behavior of the suspension were systematically investigated and the fused silica suspension with high solid content (up to 52 vol%), low viscosity and good coagulation properties were prepared at 1.8 wt% TMAH and 0.5 wt% Isobam dosage. After sintering at 1260 °C for 4 hours, the fused silica ceramics (50 vol% solid content) shows a high bending strength of 61.59 MPa, the lowest dielectric loss tanδ of 8.46×10^-4 and the dielectric constant of 3.72. Thus, this work provides a simple and effective method for preparing fused silica and other ceramics with negative surface charge by Isobam SCC.