共查询到20条相似文献,搜索用时 140 毫秒
1.
6种铝阳极氧化无铬封孔膜的性能比较 总被引:2,自引:0,他引:2
为了消除铝阳极氧化膜高耐蚀封孔液中六价铬对环境的污染,对LY12铝合金阳极氧化膜分别进行勃姆石溶胶封孔、硝酸铈溶液封孔、Ni2+-Co2+盐高温水解封孔、Co2+-三乙醇胺常温封孔和Ni2+-F--Zn2+盐常温封孔,测试无铬封孔膜的膜重,磷铬酸酸浸失重,酸性点滴液变色时间,并进行染色试验,然后与沸水封孔、重铬酸钠封孔工艺做对比.结果表明,无铬封孔方法中勃姆石溶胶法制得的封孔膜的点滴液变色时间最长为36 min,酸浸失重量最小为2.45 g/m2,且封孔膜染色后膜颜色最浅;极化曲线和电化学阻抗谱显示封孔膜的耐3.5%NaCl腐蚀性由强到弱依次为:勃姆石溶胶封孔膜>重铬酸钠封孔膜>Ni2+-F--Zn2+封孔膜>沸水封孔膜>Ni2+-Co2+封孔膜>硝酸铈封孔膜>Co2+-三乙醇胺封孔膜,且盐水中溶胶封孔膜的腐蚀电流密度比重铬酸钠封孔膜的低2个数量级. 相似文献
2.
铝阳极氧化膜中温封孔工艺研究 总被引:1,自引:1,他引:1
铝阳极氧化膜的常温封孔工艺应用广泛,但厚膜封孔比较困难,染色膜封孔时多数染料都会流色,导致封闭质量不佳.为此,研究了一种新型的铝阳极氧化膜中温封孔工艺,并筛选了抑灰剂、封闭盐及其他辅助成分,研制出MS-05中温封孔剂,其分为A型和B型两种产品,其中A型是无氟、无镍的环保型封孔剂,B型是醋酸镍型封孔剂.与日本同类产品进行对比的结果表明:A型不适用于染色膜的封孔,但对无色和电解着色膜具有优异的封孔质量;B型与日本同类产品等效,适应于包括染色膜在内的所有阳极氧化膜,解决了厚膜封孔及染色膜封孔的问题.此外,还对常温封孔和中温封孔两种类型的封孔工艺的优劣做了分析和讨论. 相似文献
3.
4.
5.
当前地勘市场还很不规范,许多个体业主并不熟悉钻探施工程序,只片面考虑成本和是否有矿。对成孔过程中的封孔并不重视和掌握这样势必给今后的钻探和开采工作带来隐患。本文根据生产实践论述了封孔的工艺要求、理论依据及提高封孔质量的措施。 相似文献
6.
7.
采用热塑性预浸料带APC-2/AS4 进行了热芯和火焰两种方法的缠绕研究, 分析了两种方法成型时预浸料带的温度2时间过程和两种方法下工艺参数对成型质量及内应力的影响。结果显示: 热芯缠绕时制件的厚度受芯模温度限制, 而火焰缠绕则不受限制。热芯缠绕时, 缠绕张力和预浸料带的树脂含量是影响制件质量的主要因素。 相似文献
8.
为解决煤矿岩巷掘进爆破施工作业中封孔工艺复杂、易冲孔以及掘进效率低等问题,设计了一种新型流体封孔材料与高效的封孔工艺。该封孔材料是由大理石粉、水与瓜尔胶三者按照70∶30∶0.15的质量比配制成的混合浆体,使用搅拌与泵送一体机,实现流体耦合封孔,并在顾北煤矿巷道掘进施工中得到应用。实验结果表明,该封孔材料具有黏度高、体系稳定和剪切变稀的流体特性,配合一体机使用,封孔工作效率提高304%,单循环进尺提高14.6%。封孔材料性能优良,封孔工艺简单,掘进效率与爆破效果得到明显提高。 相似文献
9.
10.
11.
12.
13.
14.
工艺参数对镁合金植酸转化膜的影响 总被引:3,自引:0,他引:3
传统铬酸盐化学转化处理能提高镁合金的耐腐蚀性能,但因处理液有剧毒而受到限制.采用环保型金属处理剂植酸对AZ31B镁合金进行化学转化处理,通过正交试验初步确定了工艺参数(植酸浓度、处理液pH值、处理时间、处理温度)对植酸转化膜耐蚀性影响的主次顺序,并优化了工艺参数.采用扫描电子显微镜(SEM)、电子能谱仪(EDS)、光学金相显微镜对植酸转化膜腐蚀前后的形貌、成分和厚度进行了分析;通过电化学测试技术和化学浸泡法测试了其耐蚀性能.结果表明:与传统的铬酸盐和磷酸盐体系相比,经植酸处理后,AZ31B镁合金在3.5%NaCl溶液中的腐蚀电位分别提高了0.06 V和0.09 V,且在相同的电位下,阳极电流密度最小,电化学性能得到显著改善,腐蚀速度降低. 相似文献
15.
16.
采用水热法合成了纯单斜晶系的可见光催化剂BiVO4,考察了水热温度、水热时间和体系的pH值对BiVO4结构和光催化性能的影响。利用XRD、SEM、BET和UV-VIS对样品进行了表征,结果表明:获得的BiVO4具有中空棒状结构,升高水热温度、提高反应溶液的pH值、延长水热时间有利于单斜晶系BiVO4的生成。确定了BiVO4的最优合成条件为:水热温度140℃,水热时间6h,反应体系pH=9。选择亚甲基蓝溶液作为光催化降解物质,研究BiVO4的可见光催化性能和催化机理。结果表明,最优条件下制备的BiVO4具有较好的可见光催化性能;同时,增加降解体系的pH值提高了催化剂对亚甲基蓝的吸附能力和活化电子的利用效率,有利于提高BiVO4的光催化性能。 相似文献
17.
18.
19.
Sorption of zinc by novel pH-sensitive hydrogels based on chitosan, itaconic acid and methacrylic acid 总被引:1,自引:0,他引:1
Milosavljević NB Ristić MĐ Perić-Grujić AA Filipović JM Strbac SB Rakočević ZLj Kalagasidis Krušić MT 《Journal of hazardous materials》2011,192(2):846-854
Novel pH-sensitive hydrogels based on chitosan, itaconic acid and methacrylic acid were applied as adsorbents for the removal of Zn2+ ions from aqueous solution. In batch tests, the influence of solution pH, contact time, initial metal ion concentration and temperature was examined. The sorption was found pH dependent, pH 5.5 being the optimum value. The adsorption process was well described by the pseudo-second order kinetic. The hydrogels were characterized by spectral (Fourier transform infrared—FTIR) and structural (SEM/EDX and atomic force microscopy—AFM) analyses. The surface topography changes were observed by atomic force microscopy, while the changes in surface composition were detected using phase imaging AFM. The negative values of free energy and enthalpy indicated that the adsorption is spontaneous and exothermic one. The best fitting isotherms were Langmuir and Redlich-Peterson and it was found that both linear and nonlinear methods were appropriate for obtaining the isotherm parameters. However, the increase of temperature leads to higher adsorption capacity, since swelling degree increased with temperature. 相似文献
20.
Thirteen commercially available antacids in tablet form were tested in healthy young volunteers using a transistorized miniature telemetric device (Heidelberg Capsule). After the radio transmitter capsule was swallowed, an alkali response test was performed, and two tablets of the antacid to be tested then administered. The recorded pH versus time curves were evaluated for onset of action defined as increase of pH to a value above 3, the maximum pH obtained, and the area under the pH versus time curve after the alkali response test and after administration of the antacid. For the latter one two areas were determined, the one above the base line and that above pH 5.5. It has been determined that to be effective in ulcer patients an antacid should bring the gastric pH to a value of 5.5 or above at which point the proteolytic enzymes are inactive. Only 9 of the 13 preparations resulted in pH above 5.5. Dividing the areas under the curve above the base line after administration of the antacid by the area under the curve obtained after the alkali test the extent of antacid capacity (E.A.C.) or “potency” of the preparation is obtained. Only four of 13 antacids resulted in an E.A.C. of more than twice that found during the alkali test. 相似文献