KD3200型全自动液压压砖机的特点及液压系统分析

ＫＤ３２００型全自动液压压砖机的开发成功,标志着中国已具备大吨位液压压砖机的设计和制造能力。ＫＤ３２００型压砖的主机架采用套筒拉杆预紧式框架结构,减少了机架的弹性变形,提高了整机刚度,节省了能量;主油缸倒置结构,增大了活动横梁的受力面积,有利于大规格砖坯的压制成型;液压系统广泛采用当今先进的液压控制技术和高集成化结构,故障隐患少,操作简便。     

德国DORST公司HPP 1500t全自动液压压砖机液压系统综合分析

前言 德国DORST技术有限公司成立于1860年,是世界著名的压制成形专业生产厂家。DORST产品涉及粉末成形压砖机、精整压机、真空挤出机、等静压压机、喷雾干燥塔以及模具设计制造等,广泛应用于粉末冶金技术、陶瓷、磁性材料、卫生洁具和日用陶瓷、硬质合金和特殊材料等领域。用于陶瓷墙地砖压制的全自动液压压砖机在我国山东、河南等地区仍有数台在使用。目前国产全自动液压压砖机已取得长足进步,但DOSRT压砖机仍有值得学习的地方。图l为该公司HPP1500t全自动液压压砖机液压系统原理图。     

Dorst1500T液压压砖机主机结构及液压系统分析

Ｄｏｒｓｔ 液压压砖机的主机结构采用了行程补偿机构（锁定系统） ,减少了高压油的消耗,节省了能量,且省去了低压油箱和充液阀;此外压制油缸直接安装在活动横梁上,提高了压砖机动梁的运动平稳性和运动精度。     

Dorstl500T液压压砖机主机结构及液压系统分析

Ｄｏｒｓｔ液压压砖机的主机结构采用了行程补偿机构，减少了高压油的消耗，节省 了能量，且省去了低压油箱和充液阀；此外压制油缸直接安装在活动横梁上，提高了压砖机动梁的运动平稳性和运动精度。     

全自动液压压砖机上横梁疲劳寿命研究

以某型全自动液压压砖机的上横梁作为研究对象，采用损伤容限设计法对其进行了较全面的疲劳寿命研究，并提出了多种改进措施，有较大的工程通用性和实用价值。     

套筒-拉杆式压砖机机架对角反复张拉时的力学研究

证明了用2台液压张拉千斤顶反复张拉四柱套筒－拉杆式压砖机机架的对角拉杆时，上、下横梁的张紧力是变化的。在此基础上，定量地推导了张拉次数和张紧力的关系。这些结论同样适用于二柱套筒－四拉杆式压砖机（如德国莱斯型）的张拉过程。     

缠绕型全自动液压压砖机的瞬态动力学分析

基于ANSYS大型通用有限元分析软件 ,通过对缠绕型全自动液压压砖机的瞬态动力学分析 ,可以确定在整个压制过程中的主机底座、横梁和立柱的应力或位移变化情况。这为主机的设计和钢丝缠绕预紧力的确定提供了重要依据。     

液压自动压砖机液压系统的常见故障及其解决途径(Ⅰ)

介绍了液压自动压砖机的主要结构性能特点,详细分析了液压自动压砖机液压传动系统的工作原理及其产生故障的主要原因,从而推导出液压自动压砖机液压系统的常见故障及其解决途径.     

大型自动液压压砖机的引进消化及其发展方向

本文首先介绍了我国大型自动液压压砖机的引进概况，分析了进口自动液压压砖机的特点，简要总结了我国自动液压压砖机的消化研制情况及存在的问题，最后指出了自动液压压砖机的发展方向。     

浅谈全自动液压压砖机的维护保养

全自动液压压砖机(以下简称压机)是一种集机械、液压、电器和气动于一体的机械设备,具有造价高、自动化程度高、精度高等特点。基于此,文章根据全自动液压压砖机的结构特点,对全自动液压压砖机各部件维护保养进行探讨。     

粉体的表面修饰与表面包覆方法的研究

通过粉体的表面修饰与表面包覆以改善粉体的分散性，粉体的表面性质乃至改变粉体的相结构和性质，已经成为超细与纳米粉体制备和应用的关键技术。本文介绍了陶瓷粉体的各种表面修饰、粉体包覆的方法、基本原理、特点，详细讨论了液相化学包覆技术。     

Si-B-O-N陶瓷粉末的制备与性能表征

本文使用溶胶凝胶法制备了有机聚合物先驱体，通过高温裂解得到了不含氧化硼的Si—B-O-N陶瓷粉末。采用XRD、FT-IR和TEM等技术分析了Si—B-O-N陶瓷粉末结构特性。研究表明Si—B-O-N陶瓷粉体呈非晶态，其中含有B—N，Si-O，Si—N-O等结构单元。粉末由球形粒子组成，其粒径在50nm左右。     

(Pb,La)(Zr,Sn,Ti)O3 陶瓷、锆锡钛酸铅镧/聚偏氟乙烯-三氟乙烯复合材料的介电性能

用固相烧结法,在1200℃烧结2．5h的条件下,制备了(Pb0.97La0.02)(Zr0.66Sn0.23Ti0.11)O3(PLZST)四方相陶瓷和陶瓷粉末,并将其与聚偏氟乙烯-三氟乙烯[polyvinylidene fluoride—trifluoroethylene,P(VDF-TrFE)]相复合制备了70％(体积分数)PLZST／P(VDF—TrFE)复合材料。用3～4MeV、剂量为60Mrad的电子束对PLZST陶瓷及其复合材料进行处理,测量其辐照前后的介电温谱,研究其弛豫性能的变化。结果表明：电子束辐照对PLZST陶瓷的介电温谱几乎没有影响,没有改变它的非弛豫特征;70％PLZST／P(VDF-TrFE)复合材料由于两相界面间的耦合作用产生微畴而具有弛豫特征,而辐照处理对P(VDF—TrFE)内部铁电宏畴的破坏使得其弛豫性能得到显改善,从而获得了一种良好的弛豫型复合材料。     

陶瓷粉化学镀钴工艺研究

根据化学镀原理,以镀后粉末的相对增重质量为主要指标,利用正交实验研究了在陶瓷粉末上进行化学镀钴。分析了钴离子浓度、酒石酸钠浓度、稳定剂浓度、温度以及pH对沉积效率的影响。测试了化学镀钴前后的微观形貌SEI图及XRD图。实验结果表明,溶液中的硫酸钴浓度、络合剂浓度、温度以及pH的增大,都会加快沉积速度。经X衍射分析表明,钴的晶体结构为体心六方结构。     

Intragranular nanocomposite powders as building blocks for ceramic nanocomposites

A powder-based bottom-up processing scheme is introduced for the production of ceramic nanocomposites. Internal displacement reactions between solid solution powders and metallic reactants proceeding via gaseous intermediates are utilized to generate nanostructured building blocks for the synthesis of ceramic nanocomposites. Subsequent rapid sintering results in ceramic nanocomposites, whose microstructures are inherited from the building blocks. This processing scheme is demonstrated for the production of titanium carbide nanocomposites featuring up to 28 wt.% intragranular tungsten inclusions derived from titanium-tungsten mixed carbide powders. Heat treatment of mixed carbide powders in evacuated ampoules containing titanium sponge and iodine at 1000°C for 24 h resulted in nanocomposite powders featuring tungsten precipitates within titanium carbide grains that were subsequently consolidated via spark plasma sintering at 1300°C for 10 min to produce titanium carbide/metallic tungsten nanocomposites. Transformation of mixed titanium–tungsten carbide powders to titanium carbide/metallic tungsten nanocomposite powders was analyzed via X-ray diffraction. Electron microscopy observations of microstructures pre- and post- sintering showed that the intragranular character of nanocomposite powders can be retained in sintered ceramic nanocomposites. The building block approach demonstrated in this work represents an improved method to make ceramic nanocomposites with majority intragranular character.     

Study of alumina ceramic parts fabricated via DLP stereolithography using powders with different sizes and morphologies

Selecting suitable ceramic powders for the preparation of UV-curable ceramic suspensions, which are well suited for printing processes and production of high-performance ceramic components, is a crucial factor in the practical industrial application of digital light processing (DLP) stereolithography. Therefore, this study aims to provide a comprehensive evaluation of alumina ceramic parts fabricated via DLP stereolithography using a variety of alumina powders with varying sizes and morphologies. Experiments were conducted to examine the rheological response, recoating performance, and curing behavior of UV-curable alumina suspensions. Additionally, the thermal decomposition behavior of three-dimensional (3D)-printed green-bodies, as well as the physical and mechanical properties of 3D-printed sintered alumina components were thoroughly investigated. The best physical and mechanical performances were achieved by printing 55 vol% suspensions prepared using near-spherical AA04 alumina powders (median diameter .4 μm). This study elucidates the effects of ceramic particle size and morphology on the entire technological process of DLP-based ceramic stereolithography, thereby establishing the guidelines for the fabrication of high-performance 3D-printed ceramic objects in industrial and engineering production by selecting appropriate ceramic powders.     

纳米远红外陶瓷粉体的制备工艺与性能研究

本研究分别采用固相合成法和液相共沉淀法制备远红外陶瓷粉体，采用X光小角散射法测试其颗粒分布和平均粒度，采用XRD分析其物相和SEM观察其显微结构形貌，结果表明，液相共沉淀法制备的远红外陶瓷粉体的平均粒度达到95纳米，且颗粒大小分布窄，而固相合成法制备的远红外陶瓷粉体颗粒粗大且不均匀，经中国计量科学研究院测试，液相共沉淀法制备的远红外陶瓷粉体的法向全辐射发射率为93％，固相合成法制备的远红外陶瓷粉体的法向全辐射发射率仅为82％。     

Ba0.6Sr0.4TiO3–MgO ceramics from ceramic powders prepared by improved aqueous gelcasting-assisted solid-state method

Based on aqueous gelcasting-assisted solid-state method (AGASSM), improved aqueous gelcasting-assisted solid-state method (IAGASSM) was proposed to prepare the 45 wt% Ba_0.6Sr_0.4TiO₃–55 wt% MgO (BSTM) ceramic powders. It is found that the BSTM ceramic powders prepared by IAGASSM are the most uniform with the smallest particles (D_av = 0.83 μm) than those prepared by solid-state method (SSM) and AGASSM. The phase compositions of the BSTM ceramic powders and ceramics from the prepared ceramic powders are the same whatever ceramic powder preparation method is adopted. Compared with SSM and AGASSM, the BSTM green samples and ceramics from ceramic powders prepared by IAGASSM are the most uniform. Furthermore, it is found that adopting IAGASSM to prepare ceramic powders could not only improve the dielectric properties of the BSTM ceramics considerably, but also decrease their sintering temperature.     

Electron Channeling Pattern of Ceramic Platelets

Electron channeling patterns (ECPs) have been generated in the scanning electron microscope from hexagonal-close-packed ceramic (tungsten carbide and silicon carbide) single crystals extracted from commercially available powders. The crystals, commonly employed as reinforcing phases in ceramic composites, were typically platelet-shaped with smooth surfaces. Their average diameter was 25 μm with a thickness ranging between 3 and 7 μm. After theoretical maps for the selected crystallographic poles were constructed with a procedure similar to that used for convergent beam electron diffraction, the experimental patterns were indexed and the crystallographic orientation of the crystals was determined. Specific applications for ceramic materials are discussed in comparison with previous work dealing with metals and, as an example of the application of the ECP method, the cleavage plane of fracture has been determined for the SiC platelet embedded in a Si₃N₄ matrix.     

常温远红外陶瓷粉和远红外日用陶瓷的研究

远红外日用陶瓷不仅对食物、饲料、水有活化作用，加速酒的发酵和成熟，而且对人体还具有保健功能。本研究采用液相法制备出纳米远红外陶瓷粉，把远红外陶瓷粉按适当比例掺入普通陶瓷釉浆中，制成常温下具有高效发射锭红外线功能的日用陶瓷产品。如瓷碗、盘、茶杯、酒具等。脸用XRD分析其物相和SEM观察其显微结构、结果表明，当远红外陶瓷粉在基釉中的添加量为10wt％时，可提高日用陶瓷釉面的光泽度和显微硬度，且釉面质量优良。经中国计量科学研究院测试，远红外陶瓷粉的法向全辐射发射率94％，远红外日用陶瓷的法向全辐射发射率达到83％以上。