泡沫陶瓷制备工艺的探讨

本文介绍了一种泡沫陶瓷的制备方法,在泡沫堆积的基础上进行了注浆成形,其气孔率由泡沫堆积情况所决定,讲座他各添加剂和烧成条件对粘土质泡沫陶瓷性能的影响,所得制品显气孔率可达95％。     

泡沫陶瓷制备工艺的探讨

本文介绍一种泡沫陶瓷的制备方法 ,在泡沫堆积的基础上进行注浆成形 ,其气孔率由泡沫堆积情况所决定。讨论了各种添加剂和烧成条件对粘土质泡沫陶瓷性能的影响 ,所得制品显气孔率可达 95%。     

碳化硅泡沫陶瓷的制备

碳化硅泡沫陶瓷具有气孔率高、热稳定性好等优良性能,被广泛用作金属溶液过滤器、高温气体和离子交换过滤器、催化剂载体等.重点介绍了碳化硅泡沫陶瓷的种类,阐述了碳化硅泡沫陶瓷的制备方法和影响碳化硅泡沫陶瓷产品性能的因素,展望了碳化硅泡沫陶瓷的发展前景.     

制备莫来石泡沫陶瓷的工艺因素

采用红柱石和a—Al2O3为原料,以聚苯乙烯粒子（EPS）为造孔剂,通过烧结法制备莫来石泡沫陶瓷。借助XRD和SEM分析获得莫来石相的组成和形貌,通过正交试验,探讨了粘结剂加入量、造孔剂粒度及球磨时间等工艺参数对泡沫陶瓷结构和性能的影响,在此基础上进一步讨论造孔剂加入量对密度和强度的影响。结果表明：粘结剂加入量对密度和强度的影响较大,造孔剂粒度次之,球磨时间影响最小。1450℃烧结,红柱石和氧化铝按质量比80：20,EPS粒径小于0．60mm、加入9wt％造孔,可以制备性能优良的莫来石泡沫陶瓷,其表观密度0．52g／cm3,孔隙率为83％,抗折强度1．54MPa。     

蛋白发泡法制备泡沫陶瓷固化工艺研究

选用蛋清蛋白作为发泡剂, 采用蛋白发泡法制备了高孔隙率的泡沫氮化硅陶瓷. 设计了三种不同固化工艺: 常压固化、恒压固化和高压固化, 固化气压依次升高, 研究了固化气压对泡沫陶瓷开孔率、孔隙形貌和孔径分布的影响. 其中, 恒压固化制品的平均孔径和开孔率最高, 分别为210 μm和78.6%, 且孔径分布比较均匀, 常压固化次之, 高压固化制品开孔率和平均孔径最低. 常压和恒压固化制品为椭球形孔洞, 有一定的排列取向, 而高压固化制品多为规则的球形孔. 随着固化气压的升高, 制品孔壁厚度增加, 高压固化制品的孔壁厚度最高, 其压缩强度接近50 MPa.     

泡沫铝合金制备工艺研究

采用正交实验方法，选择三种不同粒径的填料，系统研究了粒子预热温度、金属液浇注温度和充型压力对渗流铸造泡沫铝合金成型工艺的影响，并对试验结果作了理论分析。认为，合理选择粒子预热温度是生产泡沫金属铸件的前提，适当提高浇注温度是保证泡沫组织均匀良好的关键，保持适度的充型压力有利于提高材质通孔率和工艺的稳定性。     

陶瓷颗粒增强泡沫铝基复合材料的制备与性能

陶瓷颗粒增强泡沫铝基复合材料是近年来开发的一种新材料。本文介绍了各种陶瓷颗粒增强泡沫铝基复合材料的制备方法及组织性能研究现状。认为今后一段时期应着重研究以下几方面问题：对泡沫铝基复合材料制备工艺做进一步的研究，优化工艺参数，使工艺更稳定可靠；分析陶瓷颗粒对泡沫铝基复合材料发泡工艺、气泡尺寸及形状的影响．深入探讨其机理，进一步解决气孔结构和均匀性问题；系统研究泡沫铝基复合材料微观组织及界面结合形态；系统研究泡沫铝基复合材料的机械性能、物理性能及其影响因素，为该类材料的应用奠定理论基础；广泛开展泡沫铝基复合材料的推广应用研究，使之尽快为工农业生产的发展做出贡献。     

用低压渗流法制备泡沫铝合金

用低压渗流法生产泡沫铝合金，研究了影响液体金属渗流高度的工艺参数，实验表明，渗流高度随着颗粒的预热温度，外加渗流压力和铝液浇注温度的升高而增加，其中颗粒预热温度的影响最为显著，其他因素的影响不大，实验还表明，颗粒尺寸对于降低渗流高度起了重要作用，颗粒尺寸越小，渗流高度越低，对于不同尺寸的颗粒，都存在一个临界预热温度。     

ZrO2泡沫陶瓷的制备及性能研究

以CeO2/Y2O3复合添加剂共稳定的TZP(四方氧化锆多晶)超细粉末为主要原料,用有机泡沫前驱体浸渍法制备多孔陶瓷。论述了有机泡沫前驱体性质、浸浆工艺、浆料组分以及烧结温度对泡沫陶瓷力学性能与显微结构的影响。得出使用弹性好、孔筋强度高、对浆料有良好吸附性的有机前驱体可以获得力学性能优良的泡沫陶瓷,并且当浆料中Al2O3为5%(w)、浆料涂覆量在0.7 g/cm3、烧结温度在1580℃时可获得最优力学性能的泡沫陶瓷材料。     

纳米结构陶瓷涂层的制备技术

与传统的微米级陶瓷涂层相比,纳米结构陶瓷涂层的结合强度、断裂韧性、耐磨性等会显著提高,目前已在军民领域开始应用。纳米陶瓷涂层的制备存在一定的特殊性和较大难度,并且制备工艺会对涂层的组织和性能产生直接影响。本文对纳米结构陶瓷涂层的制备技术进行了详细介绍。     

Magnesium Filtration with Ceramic Foam Filters and Subsequent Quantitative Microscopy of the Filters

Magnesium alloy AZ91 melts have been filtered through ceramic foam filters in laboratory scale experiments. Inclusion contents in the melts were adjusted by adding fractions of return die cast metal. During the experiments metal flow and metal temperatures were logged. The results show that the transition from depth to cake filtration is quite pronounced. This indicates that depth filtration and cake filtration act in sequence. Some of the filters have been sliced in the flow direction and analyzed for oxide inclusions employing automatic image analysis. The results from the metallographic examinations indicated that the filtration efficiency of the ceramic foam filters was very good. However, the filter life might be considered unacceptable.     

Production of Metallic Foams From Ceramic Foam Precursors

A process has been developed for obtaining closed cell metallic foams using a ceramic foam precursor. In this approach, the major constituent of the ceramic foam precursor is iron oxide (Fe₂O₃), which is mixed with various foaming/setting additives. The mixture sets rapidly at room temperature to stabilize the foam generated by hydrogen release. The oxide foam is then reduced in a non‐flammable hydrogen/inert gas mixture to obtain a metallic foam with a cell diameter of 0.5–2 mm. Iron foams with a relative density of 0.23 were tested in compression and yielded an average compressive strength of ～ 34 MPa. The compressive stress‐strain curves obtained were typical of cellular metals. The normalized strengths of the metal foams obtained in the present study compare very favorably with that of steel foams produced by other techniques.     

Fabrication of Near Net Shape Metallic Foam via Plaster Mould

Fabrication characteristics are unstable in direct foaming method. Therefore, most of near net-shape metallic foams are produced, and investigated by powder metallurgy. Direct foaming method, however, has many benefits （i.e. reduce the unit cost of goods and fabrication process etc.） to fabrication of metallic foams. In this article, the fabrication characteristic of near net-shape metallic foams by direct foaming method was evaluated. Al and Plaster was used for base material and mould material respectively. Ca and TiH2 were added to molten Al as thickening and blowing agent for stable condition of bubbles. Thickening time was about 10 min with a stirring speed of 600 r/min. Foaming time was 30-120 s for evaluation of the optimum foaming condition. Amount of agent was selected by pre-experimental data. Porosity of near net-shape goods was measured by Archimedes method. On the other hand, it seems that increasing poring time and thickening agent make the poor porosity     

碳化钛泡沫陶瓷的筋内组织

本文研究了碳化钛泡沫陶瓷的筋断面组织、发现高真空烧结使筋结构网状化，钼的加入有利于筋的致密化，但不如降低烧结真空度致密化效果明显。     

泡沫陶瓷压缩性能的实验研究

研究了两种不同工艺(11#自然硬化法和22#烧结法)生产的泡沫陶瓷分别在1mm／min和5mm／min的变形速率和不同方向受到单向压缩条件下的应力—应变曲线或力—位移曲线。结果表明：泡沫陶瓷受压缩的应力—应变曲线并不具备泡沫材料受压缩的典型应力—应变曲线的三阶段特征，它没有明显的弹性变形段，只有屈服平台段和紧实段；在压缩过程中，11#泡沫陶瓷的骨架变形以弯曲为主，22#泡沫陶瓷的骨架变形主要是由局部断裂产生；泡沫陶瓷结构为各向同性。     

粉末冶金泡沫铝的研究进展

泡沫铝是一种新型的超轻多功能材料。粉末冶金发泡法因能制备异型泡沫铝和泡沫铝芯三明治复合结构．可满足汽车、航天、航空和军工等领域的需求，已成为当前泡沫铝研究的热点方向.本文介绍了国内外粉末冶金泡沫铝方面的研究现状，指出了现存问题。并展望了今后的发展趋势。