共查询到20条相似文献,搜索用时 62 毫秒
1.
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.
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.
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.
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.
Rundong Fan Huizhong Zhao Han Zhang Pengda Zhao Jianwei Chen Xianghui Wang 《Ceramics International》2019,45(9):11204-11215
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.
18.
19.