首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
常规的铝阳极氧化膜由于表面电阻大而无法满足产品的电磁屏蔽性能要求。为提高铝氧化膜的电磁屏蔽性和耐蚀性,提出了一种铝合金导电氧化工艺。介绍了其原理、工艺流程及工艺维护,测量了所得膜层的外观、导电性和耐蚀性。结果表明,该工艺所得氧化膜无色透明、导电性好,且具有一定的耐蚀性。  相似文献   

2.
以电连接器用ZL101A铝合金为基体进行酒石酸-硫酸阳极氧化,同时进行硫酸阳极氧化作为对照.表征了硫酸氧化膜和酒石酸-硫酸氧化膜的表面形貌,并测试了两种氧化膜的表面粗糙度、化学成分及耐蚀性.结果表明:两种氧化膜的厚度均匀性和平整度都较好,与硫酸氧化膜相比,酒石酸-硫酸氧化膜表面的孔洞数量较少.两种氧化膜都含有Al、O、S和C元素,同一元素的质量分数相差不大.两种氧化膜在NaCl溶液中的耐蚀性都强于铝合金基体,与硫酸氧化膜相比,酒石酸-硫酸氧化膜的腐蚀电位正移了约60 mV,腐蚀电流密度降低了约27%,电荷转移电阻和膜层电阻都增大,对铝合金基体的保护效率接近89%,表现出更好的耐蚀性.  相似文献   

3.
压铸镁合金阳极氧化膜的研究   总被引:1,自引:0,他引:1  
研究了压铸镁合金AZ91的阳极氧化膜的工艺及其耐蚀性,探讨了镁合金表面阳极氧化膜的组织、相、成分及其耐蚀性。研究结果显示,压铸镁合金AZ91阳极氧化膜表面系氧化物的聚集,阳极氧化膜在3.5%NaCl中的极化曲线与AZ91压铸镁合金的极化曲线对比,阳极氧化膜的极化曲线有明显的钝化区,但在极化区只呈锯齿状变化,耐蚀性较好。  相似文献   

4.
使用草酸阳极氧化技术对汽车用5052铝-镁合金进行阳极氧化处理,并研究了阳极氧化对铝-镁合金耐蚀性的影响。铝-镁合金的阳极氧化属于氧化膜的生成和溶解的动态过程。氧化膜主要由多孔层和阻挡层构成,厚度约为8μm。经过阳极氧化处理后,铝-镁合金的耐蚀性显著提高。重铬酸钾封闭后,腐蚀电流密度下降为原来的10%,膜电阻显著增大,进一步提高了铝-镁合金的耐蚀性。  相似文献   

5.
采用微弧氧化工艺对汽车用7075铝合金进行处理,生成氧化铝陶瓷膜。微弧氧化初期,随着微弧氧化时间的延长,致密层增厚,微弧氧化膜的硬度和耐蚀性显著提高;当微弧氧化时间大于100min时,由于致密层难以击穿,表面的疏松层导致微弧氧化膜的硬度增加缓慢,耐蚀性下降。微弧氧化时间为100min时制备的微弧氧化膜具有较高的硬度和最佳的耐蚀性。  相似文献   

6.
铸铝合金硫酸阳极氧化   总被引:6,自引:1,他引:5  
研究了铸铝合金的表面预处理和阳极氧化工艺;讨论了铸铝合金的表面预处理和工艺条件对阳极氧化膜耐蚀性与厚度的影响;获得了合适的表面预处理方法和阳极氧化工艺条件。  相似文献   

7.
在100g·L-1硼酸盐,50g·L-1铝酸盐,30g·L-1氢氧化物,恒压50V,阳极氧化时间10min的阳极氧化工艺中,制备AD91镁合金阳极氧化膜.研究热水封孔前后阳极氧化膜层的微观结构及耐腐蚀性能.通过扫描电镜(SEM)和极化曲线分别研究了AD91镁合金阳极氧化膜的表面形貌和耐蚀性.结果表明:封孔温度在70℃,时间为10min时,氧化膜层均匀、致密,孔径明显减小;此时阳极氧化膜的耐蚀性也达到了最好.从极化曲线可以看出,腐蚀电位Ecorr为-0.582V,腐蚀电流密度icorr为4.586uA·cm-2,极化电阻Rp为12926.lohm·cm-2.  相似文献   

8.
镁合金阳极氧化   总被引:1,自引:0,他引:1  
镁合金以优良的物理、机械性能得到了广泛的应用,而耐蚀性差制约其进一步应用.对镁合金进行适当的表面处理能够提高耐蚀性.阳极氧化膜具有与基体金属结合力强、良好的耐蚀性及耐磨损等优点,同时具有多孔结构,能够按照要求进行着色/封孔处理,并能为进一步涂覆有机涂层提供优良底层,阳极氧化工艺是目前普遍应用的表面处理方法.本文介绍了镁合金阳极氧化工艺的发展概况,阳极氧化工艺的成膜机理,膜的耐蚀性影响因素等.  相似文献   

9.
脉冲技术在铝合金硬质阳极氧化中的应用   总被引:10,自引:1,他引:10  
阐述了铝合金硬质阳极氧化的工艺条件,特点及应用现状,提出将脉冲技术应用于铝合金硬质阳极氧化。比较了脉冲硬质阳极氧化膜与普通硬擀阳极氧化膜的各项性能。脉冲硬质阳极氧化膜在硬度、耐蚀性、柔韧性、抗电击穿性和膜厚均匀性等方面都优于普通硬质氧化膜。此外,从理论上探讨了脉冲硬质阳极氧化膜的生长过程。  相似文献   

10.
镁合金微弧氧化陶瓷膜具有较好的耐蚀性和机械性能.综述了镁合金微弧氧化膜耐蚀性、硬度、摩擦磨损和拉伸性能等的最新研究进展,归纳了电解液成分和工艺参数对陶瓷膜耐蚀性和机械性能的影响.概括了镁合金微弧氧化处理技术的不足之处.  相似文献   

11.
在逆流式冷却塔的空气阻力计算中,常常忽略了雨区阻力的计算,包括国标规范与高等教育的教科书等权威文献也未提及,根据工业塔的实测,这部分阻力占全塔空气阻力的1/6左右。本文根据冷却塔设计与运行的实践,并结合国内外学者对此的实验研究成果,经分析总结,给出了一个较为系统可行的计算方法,经验证与工业塔实测基本吻合,可供冷却塔设计中参考使用。  相似文献   

12.
综述了聚邻苯二甲酰胺(PPA)的特性和应用,对部分PPA新品种制备方法及表征测试作了介绍,还介绍了PPA在耐热性、吸水性、尺寸稳定性、耐焊锡性等方面的研究进展。  相似文献   

13.
《Ceramics International》2022,48(21):31909-31913
Enamel–metal composite materials with high strength and corrosion resistance are often used for fabricating enameled pressure vessels for pharmaceutical and chemical production. However, the low bending resistance of the enamel can result in the cracking and delamination of the enamel layer, leading to the loss of corrosion resistance of the enameled pressure vessel, which can result in accidents. Here, based on the goal of increasing the bending resistance of the enamel to prolong its service life, the effect of β-Si3N4 whiskers on the mechanical properties of enamel was studied by three-point bending tests. The effect of β-Si3N4 whiskers on the acid and alkali corrosion resistance of enamel was studied using aqueous H2SO4 and NaOH solutions, respectively. A sudden change in the force of an enameled sample under the three-point bending test was used to evaluate the bending resistance of the enamel–metal samples, and can also be used to evaluate the mechanical properties of other comparable materials. With the addition of 0.5 wt% β-Si3N4 whiskers, the bending resistance was significantly improved, along with the acid and alkali corrosion resistance. These findings are expected to provide guidance for the design and production of enamel-metal vessels with improved performance that can significantly lengthen the service life of enameled pressure vessels and reduce the occurrence of accidents.  相似文献   

14.
介绍了电阻涂料底漆、面漆的种类和各类电阻涂料底漆和面漆的组成、特点及技术规格。同时,还简介了环氧型、油墨型及有机硅型标志涂料的特点和技术指标。  相似文献   

15.
Alumina–chromium slag (ACS), a cheap and abundant refractory raw material comprising aluminum–chromium oxides and β-Al2O3, is a byproduct of ferrochrome smelting. For this reason, we investigated the relationships between composition and mechanical properties, abrasion resistance, oxidation resistance, and resistance to iron slag erosion for Al2O3–SiC–C trough castables in which ACS was substituted for alumina. Due to the presence of β-Al2O3 in ACS, the aluminum-chromium slag reacted with SiO2 to form a low-melting phase of albite and promoted the formation of mullite, which filled the pores at high temperatures and reduced the porosity, thereby promoting densification and strengthening of the sample. The cold mechanical properties of the sample and the normal temperature wear resistance were enhanced, but the high-temperature mechanical properties and the resistance to iron slag corrosion of the sample were impaired. According to the results of the anti-oxidation experiment, the presence of β-Al2O3 in the ACS reduced the porosity and made the sample more dense, which remarkably improved oxidation resistance of the sample. For industrial production requirements, ACS substitution should not exceed 48?wt% due to of thermomechanical properties and anti-slag corrosion performance in Al2O3–SiC–C trough castables.  相似文献   

16.
《Ceramics International》2022,48(10):13987-13995
The purpose of this paper was to develop ceramics materials with high thermal shock resistance and corrosion resistance for preparing gas blowing components. In this paper, MgO-rich MgO–ZrO2 ceramics were obtained by using MgO powder and ZrO2 powder as starting materials and CeO2 as an additive. Changes in the properties in terms of thermal shock resistance, mechanical properties, and slag corrosion-resistance with chemical compositions were examined correlated to microstructure and phase changes. Especially, the effect of doping CeO2 on phase transition of zirconia in MgO-rich system was discussed. The results showed that doping amount of CeO2 significantly improved properties of MgO–ZrO2 ceramics. Especially when doping amount of CeO2 was 2 wt%, residual strength ratio was enhanced over 100% after thermal shock testing. In samples doped with CeO2, ZrO2 was stable in cubic or tetragonal form due to complete solution of CeO2, which was important reason for the improvement of various properties of MgO–ZrO2 ceramics.  相似文献   

17.
氧化镁-尖晶石浇注料的组成与性能的关系   总被引:4,自引:3,他引:1  
以中档烧结镁砂、矾土基尖晶石和电熔白刚玉为主要原料,制备了不同基质组成的试样,并研究了浇注料的流动性、强度、永久线变化率、抗渣性和抗热震性。结果表明:基质的组成(特别是Al2O3/MgO比)对浇注料的抗渣性、线变化率、抗剥落性和热震稳定性有显著影响,通过调整Al2O3/MgO比可制得综合性能优良的氧化镁-尖晶石浇注料  相似文献   

18.
硅树脂及其涂料的研究新进展   总被引:1,自引:0,他引:1  
综述了近十年来国内外耐热、耐腐蚀、耐候性硅树脂、改性硅树脂及其涂料的研究新进展;指出了硅树脂及其涂料的发展趋势。  相似文献   

19.
曹广军  常亚娜  韩杰 《氯碱工业》2010,46(10):36-38,41
对钢骨架塑料复合管与其他管道的性能进行了比较,对比结果证明:钢骨架塑料复合管具有耐压、耐磨、耐腐蚀、抗蠕变、安装方便以及较高的性价比等特点。  相似文献   

20.
无醛防皱整理剂的研究进展   总被引:1,自引:0,他引:1  
传统的防皱整理的发展历程及面临的新问题,阐述了多元羧酸类防皱整理剂作为棉织物理想的无甲醛防皱整理剂的防皱机理及性能,但由于它存在价格贵、织物泛黄色变、耐洗牢度差、含磷催化剂污染环境等问题,需要有效解决。最后,指出了无醛防皱整理今后的发展方向。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号