Ni-SiC复合电镀工艺的优化及镀层结构表征

利用电沉积法制备出Ni-SiC复合镀层,研究了阴极电流密度、温度、pH、搅拌速率、表面活性剂等工艺参数对镀层显微硬度和沉积速率的影响,通过正交试验得出了最佳工艺参数:阴极电流密度4A/dm2,SiC微粒悬浮量60g/L,温度40℃,pH 2.5,搅拌速率300 r/min.用SEM、XRD和TEM分析了镀层的表面形貌、组织结构及镀层中粒子的分布,结果表明:SiC微粒均匀分布于复合镀层中,镀层表面平整光滑,显微组织均匀、致密,其显微硬度也较纯镍镀层有显著提高.     

脉冲电沉积Ni-SiC复合镀工艺的研究

采用脉冲电镀在45#钢表面制备含有SiC微粒的镍基复合镀层,研究了镀液中SiC的质量浓度、脉冲平均电流密度、pH值对Ni-SiC复合镀层的影响规律.结果表明:电镀工艺条件的改变影响复合镀层中SiC的共沉积量和镀层的硬度,当镀液中SiC质量浓度为20 g/L,平均电流密度为40 A/dm2时,镀层中SiC体积分数为14.3%,硬度约为镍镀层的1.7倍.     

Ni-SiC纳米复合电镀工艺的研究

分析了镀液中纳米SiC悬浮量、阴极电流密度、镀液pH值、温度以及搅拌速度对复合沉积层中纳米SiC复合量和共沉积速率的影响,同时用正交实验法优选了各工艺参数,并且对Ni-SiC纳米复合镀层进行了表面形貌和能谱分析.结果表明,Ni-SiC纳米复合镀层表面平整光滑,显微组织均匀、致密,并且,其显微硬度也较纯镍镀层有明显提高.     

工艺参数对Ni-SiC复合镀层的影响

采用复合电镀工艺制备了Ni-SiC复合镀层,研究了电流密度、镀液温度、pH、镀液中SiC、十二烷基硫酸钠和硫酸钴质量浓度对镀层中SiC的影响。确定了最佳工艺参数,Jκ为1.2A/dm2,θ为40℃,pH为4.2,20g/L SiC,0.1g/L十二烷基硫酸钠,采用该工艺可以获得复合镀层中SiC质量分数较高且镀层结合力较好的复合镀层。     

脉冲电沉积Ni-ZrO2复合镀层形貌的研究

着眼于优选电沉积工艺条件,以期制备出良好形貌的复合镀层,系统考察了峰值电流密度、占空比和微粒的质量浓度对脉冲电沉积Ni-ZrO2复合镀层形貌的影响。结果表明:Ni-ZrO2复合镀层的形貌质量随峰值电流密度的增加和微粒质量浓度的升高呈现出先改善后恶化的趋势,但随占空比的增大逐渐变差。在峰值电流密度7A/dm2,占空比20%,微粒的质量浓度20g/L的条件下,所得Ni-ZrO2复合镀层的形貌质量最优。     

钛合金表面Ni-TiB2复合镀层的结构与性能

在Ti-6Al-4V钛合金表面制备了Ni-TiB_2复合镀层。通过单因素试验,研究了镀液中TiB_2的质量浓度、搅拌速率和电流密度对复合镀层中TiB_2的质量分数的影响。优选出的最佳工艺参数为:镀液中TiB_2的质量浓度12g/L,搅拌速率500r/min,电流密度3A/dm~2。同时,获得了TiB_2的质量分数较高(约为9%)的复合镀层。Ni-9%TiB_2复合镀层表面较致密,其硬度约为钛合金基体的2倍。     

镍基SiC纳米微粒复合电镀研究

以镀层中SiC复合量为参考标准,通过正交试验,考察了SiC纳米微粒、电流密度、pH和空气流量四个因素对SiC复合量的影响,发现镀液中的SiC纳米微粒质量浓度对复合量影响最大。根据正交试验结果得出镍基SiC纳米微粒复合电镀的最佳工艺条件。在最佳工艺条件下,对Ni-SiC复合镀层表面形貌和能谱进行分析。     

碱性锌酸盐电镀锌–碳化硅复合镀层工艺优化

以Q235钢板为基体,在由70.0 g/L氧化锌、180.0 g/L氢氧化钠、2.8 g/L香草醛、1 m L/L甲醛、1.0 g/L硫脲和1.0 g/L三乙烯四胺组成的普通碱性镀锌液中加入SiC微粒电镀得到Zn–SiC复合镀层。研究了电流密度、温度、SiC用量和搅拌速率对Zn–SiC复合镀层耐蚀性的影响,得到较佳工艺条件为:SiC用量8 g/L,电流密度2.5~4.0 A/dm~2,温度20~25°C,搅拌速率120 r/min。SiC的存在有利于生成晶粒细小、致密且显微硬度较高的镀层。在较佳工艺下,Zn–SiC复合镀层中SiC的质量分数为1.51%,其耐蚀性优于纯锌镀层。     

工艺参数对Ni-SiC纳米复合镀层硬度的影响

为了提高结晶器铜板的使用寿命,采用电沉积的方法得到了Ni-SiC纳米复合镀层。采用单因素实验法对影响电镀层硬度的阴极电流密度、SiC纳米微粒添加量、pH及温度等进行了研究。结果表明,Ni基SiC纳米复合电镀工艺参数均对复合镀层的硬度有影响。对Ni-SiC纳米复合镀层的表面形貌进行了测试,确定最优工艺条件为8g/L SiC纳米微粒,Jκ为3A/dm2,pH为4.0,θ为30℃。纳米复合镀层的硬度与纯镍镀层相比有明显提高。     

复合电沉积铜-钨合金工艺及其机理的研究

分析了阴极电流密度、微粒的质量浓度、温度、搅拌速率等对铜-钨复合镀层中钨微粒的体积分数的影响。用扫描电镜观察正交优化工艺制备的复合镀层,结果表明:镀层电沉积结晶均匀、细致。此外,对复合电沉积铜-钨的过程机理进行了初步探讨,结果表明:在低电流密度条件下,铜-钨复合镀层的沉积遵循Guglielmi模型机理。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

我国聚碳酸酯工业发展概况

介绍我国聚碳酸酯生产能力和消费需求,对聚碳酸酯在信息工业中的应用作了简短介绍     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

气化给煤系统故障分析

气化给煤装置自投运以来,出现了气化煤仓堵煤、称重给煤机输送皮带因跑偏而损伤以及清扫装置故障频繁等问题,多次造成气化系统减负荷运行。通过对出现的各种问题进行分析,找到了产生这些问题的原因,并有针对性地采用配煤和改进清扫链等措施,使出现的问题得到了极大的改善。     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003