金属拔丝用中温磷化液的研制

研制了了一种使用方便,性能优良的金属拔丝用中温锌系磷化液,并对磷化膜的形成机理进行了探讨,根据实验结果分析讨论了游离酸度,总酸度等因素对磷化膜质量的影响。     

常温锌系磷化液消耗规律及成膜机理的研究

为得出常温锌系磷化液消耗规律及成膜机理,通过用HG-6061Ⅱ型磷化液对碳钢试片进行反复磷化处理,定期测定工作液各组分的含量,找出消耗规律,制备出校正液和工作液的调整方法.并对磷化膜进行了SEM形貌和XPS能谱分析.推断出成膜反应机理和膜的形态及组成.     

高酸度磷化液成膜机理探讨

有关高酸度磷化液的成膜机理目前尚无定论,作者通过对高酸度磷化液进行反复的实验,主要从时间、温度、促进剂等因素对高酸度磷化液所形成的磷化膜的耐蚀性的影响进行了讨论,并在此基础上初步探讨了高酸度磷化液的成膜机理, 形成的磷化膜为非晶型的磷酸铁盐.     

环保型单组分低温磷化液的研制与应用

从环保、质量和处理工艺的角度对单组分膜和彩膜磷化液的配方设计、处理工艺等进行了详细的论述,并通过大量实验提出了该产品的最佳椟方及处理工艺。     

钡盐改性常温锌钙系磷化液

通过扫描电镜及能谱仪(SEM EDS)扫描、氯化钠溶液腐蚀试验等方法研究了硝酸钡、SO24-对常温锌钙系磷化的影响。结果表明,磷化液中的SO24-会进入磷化膜,且不能通过水洗磷化膜清除,明显影响锌钙系磷化膜的性能,甚至引起磷化液报废;添加Ba2 ≤0.9g/L可有效除去磷化液中的SO24-;改变磷化膜的组成并提高磷化膜的耐蚀性能。     

Self-organized nano-scale multilayer coating on SiC fibers obtained by phosphating

Ceramic matrix composites (CMC) combine refractory and structural properties, with a damage-tolerant behavior ensured by an interphase material, usually deposited on fibers. Unfortunately, surface deposition does not prevent contacts between fibers, which are responsible for the premature collective failure of fiber clusters and therefore for limited lifetime. Recently, a workaround has been proposed by transforming the surface of the fibers itself into a continuous monolayer coating. Here we describe an SiC fiber etching process by phosphoric acid vapors at atmospheric pressure and intermediate temperature (600–700?°C), leading to an in situ multilayer transformation into a (carbon/silicophosphate)_n coating, n ranging from unity to tens and layers thickness from 100 to 300?nm. The carbon layers are micro/mesoporous carbide-derived carbon (CDC) tubes with micrometric radii. This one-step etching process gives opportunity to create layered materials containing CDC even on complex geometries such as fabrics.     

油套管接箍锰系磷化工艺研究

通过正交试验设计方法确定了锰系磷化工艺的工艺参数,研究了磷化液酸比、磷化时间和磷化温度等工艺参数对磷化膜成膜的影响,分析了各工艺参数对磷化成膜的作用机理.用经过磷化处理的接箍进行上、卸扣试验,结果表明,得到的磷化膜具有良好的抗粘扣性能.     

低温磷化现状及发展趋势

低温磷化由于低能耗、低成本、低污染等特点,日益受到人们的关注.对低温磷化的特点、机理、促进剂、现状进行了研究,结果表明:目前主要采用电化学方法、化学方法、调整酸比和pH值等方法来降低磷化处理的温度,但低温磷化仍存在耐蚀性较差的缺点,难以满足大规模工业应用.由于磷化过程的复杂性,低温磷化的机理以及复合促进剂仍将是今后研究的重点.     

Effect of surface mechanical attrition treatment (SMAT) on zinc phosphating of steel

The effects of surface mechanical attrition treatment (SMAT) of EN8 steel on the growth of phosphate coatings, morphological features and corrosion resistance of the resultant coatings have been studied. SMAT enabled the formation of a uniform surface profile although the average surface roughness is increased after treatment. SMAT increased the extent of metal dissolution and the rate of growth of phosphate coating. In spite of the similarity in phase composition, the phosphate crystallite size is relatively high for samples treated by SMAT. Compared to the untreated one, a cathodic shift in E_corr with a corresponding decrease in i_corr is observed for SMAT treated EN8 steel after phosphating. For all tested samples, zinc phosphate coatings deposited on EN8 steel after SMAT using 8 mm Ø balls for 30 min offers the highest corrosion resistance. The increase in surface roughness by SMAT is partly compensated by the expected improvement in corrosion resistance.     

Characteristics of a fast low-temperature zinc phosphating coating accelerated by an ECO-friendly hydroxylamine sulfate

A fast low-temperature phosphating processing accelerated by an ECO-friendly hydroxylamine sulfate (HAS) is developed. The zinc phosphate coating was fast formed on high-carbon steel in a low-temperature phosphating bath. Growth stages and characteristics of the phosphate coating were investigated by open circuit potential (OCP), SEM, EDS and XRD techniques. The phosphating process can be divided into three stages, namely amorphous precipitation, anodic depolarization and growth of phosphate coating. The phosphate coating consists of Zn₃(PO₄)₂ · 4H₂O and Zn₂Fe(PO₄)₂ · 4H₂O phases. The addition of HAS makes the three stages' time shorten to 53%, 31% and 50%, respectively, while markedly reduces the size of phosphate crystals from 100 µm to about 50 µm, and increases the Zn₂Fe(PO₄)₂ · 4H₂O content from 30% to 44% in the coating. HAS would be widely used as a low-temperature phosphating accelerator to replace the traditional nitrite, due to its less pollutant, higher phosphating rate and better quality of the coating.