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1.
以堇青石、板状刚玉、α-Al2O3和高岭土为主要原料,制备出用于过滤铝液的高性能泡沫陶瓷.考察了分散剂和固含量对堇青石氧化铝浆料黏度及性质的影响,以司马化工CE64作为分散剂可以得到固含量为82%(质量分数),流变性能较好的浆料.经1350~1400℃烧结后制品孔隙率为80%~85%,耐压强度达到1.5 MPa,热震性达5次以上.  相似文献   

2.
Tiron对纳米Al2O3悬浮液性能的影响   总被引:10,自引:0,他引:10  
以1,2-二羟基苯-3,5-二磺酸钠(Tiron)为分散剂获得了平均粒径约为57nm的氧化铝粉体的稳定悬浮液。通过测定等温吸附曲线及悬浮液的Zeta电位,研究了Tiron对粉体表面特性的影响。结果表明,Tiron在Al2O3表面发生化学吸附,磺酸基的离解使胶粒表面电荷更负,显著提高颗粒表面的带电量,从而改善浆料的稳定性。FTIR研究表明:Tiron分子结构中两个相邻羟基与Al-OH形成内环结构,从而提高了吸附强度。流变测试确定了制备在含量稳定浆料在pH=8.5时所需的最佳分散剂用量为0.8wt%。  相似文献   

3.
采用低毒的单体N, N-二甲基丙烯酰胺(DMAA)制备了氧化锆增韧氧化铝(ZrO2/Al2O3)坯体。讨论了分散剂的用量、 ZrO2/Al2O3浆料的pH值、 粉体中ZrO2含量、 粉体所占浆料的固相体积分数、 球磨时间、 预混液中DMAA的浓度(质量分数)对ZrO2/Al2O3浆料黏度的影响。并研究了注凝成型ZrO2/Al2O3坯体的性能和显微结构。结果表明, 当浆料pH值为9, 分散剂的添加量为ZrO2/Al2O3粉体质量的0.6%, 球磨时间为6 h, ZrO2/Al2O3浆料具有最小的黏度。固相体积分数的提高和DMAA加入量的增大都会提高ZrO2/Al2O3浆料的黏度, ZrO2的加入会降低浆料的黏度。用DMAA制备得到的ZrO2/Al2O3坯体结构均匀, 抗弯强度达到25 MPa。   相似文献   

4.
凝胶注模成型工艺的关键是高固相含量、低粘度的氧化铝浆料悬浮液的制备,要有利于注模操作,同时保证产品强度,所以浆料的黏度对于该工艺至关重要。因此,本文通过设计一组三因素三水平的正交实验探讨了分散剂、PH和球磨时间等因素对氧化铝陶瓷浆料黏度的影响。通过实验可以发现分散剂的含量对浆料粘度的影响最大,所以又单独通过实验分析了分散剂对陶瓷浆料粘度的影响。最终通过实验得到的结论为:分散剂加入为2wt%,球磨时间为2个小时,PH值为9,一定体积分数陶瓷浆料的粘度最小。  相似文献   

5.
研究了工艺参数对氧化锆流延片制备影响.结果表明,当流延体系9<pH<11.5,分散剂用量为1.5wt%,黏结剂含量为5wt%,球磨混合12h的ZnO2浆料稳定,素坯质量好.在1500℃经3h烧结,烧结样品显微结构致密,相对密度达98%.  相似文献   

6.
以BaCO3和TiO2粉末为原料,采用固相反应法合成Ba2Ti9O20的粉体,并以此粉体为主要原料添加适量的分散剂、粘结剂及塑性剂,采用流延法制备Ba2Ti9O20陶瓷膜片。研究了不同种类和配比的溶剂、不同种类和含量的分散剂对Ba2Ti9O20流延浆料的流变特性的影响。结果表明,当选用异丙醇和甲苯(体积比为75:25)为溶剂,固含量Ba2Ti9O2054wt%,分散剂蓖麻油0.5wt%,粘结剂聚乙烯醇缩丁醛5wt%,塑性剂聚乙二醇5wt%时,流延浆料的流变性能较好,浆料的粘度为9.1Pa.s。  相似文献   

7.
片式BaTiO3基PTCR注浆成型研究   总被引:1,自引:0,他引:1  
研究了片式BaTiO3基PTCR,元件石膏模注浆成型工艺,通过控制pH值、粘合剂及分散剂的含量,获得具有较高固相比和较低粘度的浆料.在PVA和分散剂占粉料质量比分别为0.8%和0.4%且pH=9时,获得的浆料最高固相质量分数为80%(固相体积分数为55%).利用注浆成型能够通过模具尺寸及吸浆时间来控制膜厚的特点,成功制备出厚度为0.4mm且具有一定强度和密度的生坯,并考察了注浆成型瓷片的PTCR效应,且对成型过程中的一些现象作出了分析和讨论.  相似文献   

8.
采用HEMA-TBA凝胶体系制备具有高气孔率, 高强度的多孔氧化铝陶瓷, 研究多孔氧化铝陶瓷的浆料和坯体制备工艺, 并系统研究了分散剂含量和固相体积分数对浆料粘度和悬浮稳定性的影响、干燥和单体含量对生坯性能的影响以及固相体积分数和烧结温度对烧结体微观结构的影响。结果表明: 加入柠檬酸可以使浆料粘度降低, 稳定性提高, 柠檬酸加入量达到2wt%后浆料粘度和稳定性趋于稳定; 固相体积分数的增加会导致浆料粘度和稳定性的增加; 生坯在干燥过程中的收缩比水基体系小很多, 干燥时间也相对更短; 单体含量对生坯强度影响较大, 当单体含量为25wt%时, 生坯强度较高; 通过选择不同的固相体积分数和烧结温度, 可以有效地控制烧结体的微观结构, 气孔率的变化范围在40%~65%, 同时烧结体强度也会随之发生变化, 变化范围在5.7~91.2 MPa。  相似文献   

9.
研究了以聚乙烯亚胺 (PEI) 为分散剂,ZrB2粉体在水相中的分散性能. 结果显示ZrB2的等电点在pH为5.7,加入PEI后的等电点移到pH为11.5. 以PEI为分散剂,在pH为8.0处制备了固含量达45vol%的ZrB2-20vol%SiC陶瓷浆料. 采用注浆成型方法制备了相对密度为53%的ZrB2-SiC陶瓷坯体,并对其进行了无压烧结,同时研究了硼粉为烧结助剂对其致密化及性能的影响. 结果表明:硼粉为烧结助剂,实现了ZrB2-SiC陶瓷的完全致密化的同时,也降低了ZrB2-SiC陶瓷的烧结温度,2100℃烧结3h后的陶瓷维氏硬度为(17.5±0.5)GPa,弯曲强度为(406±41)MPa,断裂韧性为(4.6±0.4)MPa·m1/2.  相似文献   

10.
凝胶浇注成型制备致密 SiC陶瓷材料   总被引:4,自引:0,他引:4  
采用一种凝胶浇注成型预配液作为陶瓷粉体的分散介质,将亚微米级SiC粉体和烧结助剂Y2O3、Al2O3直接混合,制得了固含量>50vol%的凝胶浇注浆料,在100s-1的剪切速率下,浆料粘度<1Pa·s,可以顺利实现凝胶浇注成型;对得到的SiC素坯进行了无压烧结.在2000℃保温1h(氩气氛)的烧结条件下,烧结体相对密度为(98.1±0.2)%,抗折强度、硬度和韧性分别为(722±70)MPa、(20.18±0.75)GPa、(4.00±0.20)MPa·m1/2.  相似文献   

11.
Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.  相似文献   

12.
In this paper, the principle of spurting take off lacquer were introduced; and with orthogonal method the unsaturate polyester was prepared ;it was easy to peel airplane paint layer off with this material and equipment.  相似文献   

13.
Quality Study of Honeycomb Core Shaping Without Wax Stabilization   总被引:1,自引:0,他引:1  
Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.  相似文献   

14.
Polylactic acid (PLA) is one of the most widely used open source fused filament fabrication materials due to its ease of extrusion, biodegradability, and mechanical strength. The mechanical strength of PLA largely depends on the proper growth of its semi-crystalline structure, which can be severely impaired by a low rate of crystallization, particularly in open source printers. This can be further aggravated by the non-uniform thermal distribution of heat that causes improper curing among the extruded beads of the printing material. As a result, PLA printed on open source printers does not achieve the best mechanical properties. This research, for the first time, proposes an additive-free solution implemented through a detailed set of experimentation to improve the curing rate through in-process temperature variations to cure the joints among the beads. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy is used to confirm the improvements in the bead joints. This work is conducted in two phases of experiments. In the first phase, a full factorial ANOVA is used to investigate various process parameters and the important variables are used in the second phase to print test specimens in four different sets.  相似文献   

15.
In continuous hot-dip galvanization process the corrosion and chemical stability of the sink roll in the galvanizing bath are important problem which effects on the quality and productivity. In order to protect the sink roll the carbide cermet and/or ceramic coatings were deposited on the surface of the sink roll. The WC-, Cr3 C2-cermet coatings were deposited by high velocity oxygen fuel (HVOF) spray, respectively. The coating samples were immersed in molten Zn-alloy containing 50 wt % aluminum at 833 K for 24 hr and 144 hr, respectively. The inter-diffusion and inter-reaction of Zn, Al and elements in coating and corrosion behaviors of these coatings were investigated by XRD, SEM and EPMA etc. The corrosion mechanisms of the carbide cermet coatings and ceramic coatings in molten High Al-Zn-alloy were approached.  相似文献   

16.
In many situations, ice often adheres to a cooling solid surface, frequently causing serious accidents. It is critical to clarify the mechanism of ice adhesion to the cooling surface in order to prevent ice adhesion. In a past study, the shearing stresses of two kinds of test plates with a copper surface having the higher thermal conductivity were measured. The shearing stress corresponds to ice adhesion force. Both shearing stresses were significantly different; however, the cause remains unclear.Therefore, the present study focuses on an oxide layer as the main factor causing the difference of both shearing stresses; the influence of the oxide layer formed on shearing stress was discussed. And in the removal and reformation processes of the oxide layer, the time variation of the shearing stress was clarified. Moreover, the relationship between the state of the copper surface and the shearing stress was also clarified by surface analysis.  相似文献   

17.
正When you are enjoying the green,energy-saving and healthy lighting of IKEA LED luminaire,you may not realize that most of IKEA’s LED bulbs are produced by the LED luminaire smart manufacturing system of Hangzhou Zhongwei Photoelectricity CO.,LTD(ZVISION).No longer enclosed in the laboratory,the product standards are brought into the factory workshop and even to the entire production process.Thus,the standards are promoted and applied in a favorable way by enterprises,benefitting consumers with high quality products.  相似文献   

18.
正The international standard,ISO 8124-6,Safety of toys–Part 6:Certain phthalate esters in toys and children’s products,was officially issued by ISO worldwide on August 15.It was the first time for Chinese experts to lead the ISO standard development in toys industry.The standard was drafted by a group of Chinese experts from SAC/TC for toys and relevant Chinese departments and finally completed by a dedicated international group of experts.ISO 8124-6 makes a substantive breakthrough in the aspects of the scope of toys,limitation of plasticizer types,control of test cost,accuracy of test,operation convenience,etc.,offering the operational guidance for toy manufactures and testing laboratories.  相似文献   

19.
正Themed on"quality,innovation,development",the first China Quality Conference(Beijing)was held in the Great Hall of the People on September 15.Chinese Premier Li Keqiang delivered an important speech at the conference.State Councilor Yang Jing and Wang Yong attended the conference with over 600 domestic and international representatives from foreign,regional and international quality organizations  相似文献   

20.
正The National Working Meeting on Land and Resources Standardization was held in Beijing on July 15,2014.Wang Min,the Deputy-Minister of the Ministry of Land and Resources,and Yin Minghan,the Chief-Engineer of SAC addressed the meeting.Representatives from relevant competent departments and technical committees were present.The meeting aims to summarize work,discuss existing problems and make clear working thoughts,promoting standardization work of land and resources to a new level.Wang Min pointed out that the standardization work of land and resources should be centered on the basic principles of"protecting land and resources dutifully,intensively and economically utilizing land and resources,and making all-out efforts to safeguard the public’s rights and interests",highlighted the  相似文献   

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