电沉积RE-Ni-W-B多元复合镀层性能研究

研究了镀液组成及工艺参数对电沉积RE Ni W B复合镀层硬度和沉积速度的影响,以及不同热处理温度下复合镀层硬度、磨损率及抗氧化性的变化规律。结果表明:在最佳工艺条件下,复合镀层的沉积速率为5 13μm/h,硬度为667HV。采用X射线能谱仪测试镀层成分表明,RE Ni W B复合镀层中各成分的质量分数分别为wW=0 49%,wB=1 17%,wCe=1 99%。热处理温度对复合镀层硬度、磨损率及抗氧化性有较大的影响,热处理温度提高,复合镀层的硬度先增加后降低,磨损率先降低后增加;当热处理温度为400℃时,硬度和磨损率分别达到最大值和最小值,即1087HV和0 64mg/(cm2·h);复合镀层的氧化增重随热处理温度的增加而增加,当热处理温度低于400℃时,镀层的氧化增重较小,热处理温度高于600℃,复合镀层的氧化增重大幅度增加。

Ni-W-B-WC复合镀层制备及性能研究

以镀层硬度和镀层外观为指标,研究电流密度、镀液中WC的含量、pH值、沉积温度对考察指标的影响。利用正交试验确定了电沉积最佳工艺条件:在超声振荡下,控制电流密度为7A/cm2,施镀温度50℃,镀液中WC的含量为20g/L,镀液pH值为5.0时,镀层硬度和镀层外观最佳。同时对Ni-W-B镀层、Ni-W-B-WC镀层的硬度、抗高温氧化性、耐腐蚀性能、表面形貌、镀层结构与成分等进行了测试。结果表明,Ni-W-B-WC复合镀层的综合性能要高于Ni-W-B合金镀层。

脉冲电沉积RE-Ni-W-B复合镀层的研究

研究了脉冲频率和占空比对电沉积RE Ni W B复合镀层硬度及沉积速率的影响 ,以及热处理温度对复合镀层硬度、磨损率及抗高温氧化性的影响。结果表明 ,当脉冲频率 (f)和占空比 (r)控制在 10 0 0Hz和 3∶1时 ,复合镀层硬度最高 ,厚度最大 ,分别为 6 36HV和 0 .0 2 81mm。使用脉冲电流 ,并在镀液中添加稀土元素 ,能有效降低镀层中镍含量 ,提高钨含量 ,降低复合镀层表面的裂痕。脉冲电沉积复合镀层的硬度均高于直流电镀复合镀层 ,磨损率均低于直流镀层。当热处理温度低于 4 0 0°C时 ,热处理温度升高 ,复合镀层硬度增加 ,在 4 0 0°C时 ,硬度最高 ,磨损率最低 ;高于 4 0 0°C后 ,两种复合镀层的硬度又开始下降 ,磨损率上升。直流及脉冲复合镀层在 6 0 0°C以下氧化增重都较小 ,6 0 0°C以后氧化增重明显增加。

Ni-W-B合金镀层的制备及性能研究

实验的目的是在镀硬镍的基础上得到性质优良的Ni-W-B合金镀层。通过单因素实验确定钨酸钠、四硼酸钠的最佳用量。通过正交试验确定电镀时的温度、阴极电流密度、电镀时间。通过硬度值、金相图、极化曲线和交流阻抗图对比优化前后合金镀层的性能。最终确定了Ni-W-B合金电镀钨酸钠、四硼酸钠最佳用量为100 g/L、75 g/L。最佳工艺为:阴极电流密度11 A/dm2,时间50 min,pH为5。此时所得镀层的硬度最大为689 Hv,镀层表面光亮,晶粒均匀细致,镀层耐蚀性增强。。

基于Box-Behnken试验设计的电沉积Ni-W-B合金镀层添加剂的制备

目的制备一种能改善电沉积Ni-W-B合金性能(硬度、光泽度和耐腐蚀性)的添加剂。方法基础镀液组成为30 g/L硫酸镍+65 g/L钨酸钠+10 g/L二甲基氨硼烷+100 g/L柠檬酸三铵,工艺条件包括pH=7.0、电流密度8 A/dm^(2)、温度60℃、电镀时间60 min。在基础镀液组成及工艺条件下,单因素试验基础上设计四因素三水平的Box-Behnken试验,以镀层硬度为响应值,研究各添加剂对镀层硬度的影响规律,得出最优的添加剂组合。采用光泽度仪、维氏硬度计和电化学工作站,研究添加剂对镀层光泽度、硬度和耐腐蚀性的影响,并使用SEM和EDS研究添加剂对镀层表面形貌及成分组成的影响。结果Box-Behnken试验得出最优的添加剂组合为0.3 g/L SDBS+0.5 g/L糖精钠+0.24 g/L烯丙基磺酸钠+0.1 g/L 1,4-丁炔二醇。复配的添加剂镀液条件下所制得的镀层硬度为499.1HV0.5,光泽度为230 GU,相较于没有添加剂的镀层硬度增大了41.6HV0.5,镀层光泽度增大了85 GU;镀层的耐腐蚀性也得到提高。根据SEM以及EDS分析结果可知,添加剂的加入能很好地改善镀层表面形貌,并且促进硼的沉积,镀层中各组分含量为Ni 58.79%、W 38.93%、B 2.28%。结论复配添加剂的加入能显著改善镀层性能,所制备镀层可获得类似不锈钢的金属光泽,能满足工业需求。

热处理温度对电沉积Ni-W-B合金镀层性能的影响

热处理温度对镀层性能有直接影响。本文以黄铜为基材,在镀液中电沉积Ni-W-B合金镀层,然后研究热处理温度变化对镀层性能的影响。采用扫描电镜(SEM)、X射线衍射(XRD)、百格刀、硬度计对镀层表面形貌、组织结构、附着力及硬度进行测试分析。结果表明,热处理使Ni-W-B合金镀层从非晶态结构逐渐转变为晶态结构,当热处理温度为500℃时,镀层的表面最为致密,镀层与基体间结合良好(ISO等级为1,ASTM等级为4B);镀层的硬度从499.1 HV增加到最大值960.5 HV,增幅达92.4%,与镀铬层相当。

稀土对电沉积Ni-W-B-SiC复合镀层组织结构及性能的影响

研究了加入稀土对电沉积Ni-W-B-SiC复合镀层的成份、结构、表面形貌、硬度等性能的影响规律．结果表明：加入稀土有利于SiC与Ni-W-B的共沉积，使镀层结晶细化，RE-Ni-W-B-SiC复合镀层的硬度高于Ni-W-B-SiC复合镀层．

电流密度对Ni-W-B合金电沉积层结构和显微硬度的影响

采用电化学技术、XRD、DSC等方法研究电流密度对 Ni- W- B合金电沉积、镀层结构和显微硬度的影响 ,结果表明 :沉积电流密度提高 ,Ni- W- B合金电沉积层 W含量增大 ,B含量降低 ,电沉积电流效率降低 .所获得的合金镀层表现为亚稳态纳米晶结构 .在不同电流密度下获得的 Ni- W- B合金电沉积层的显微硬度值接近 ,约为 650 kg/mm2 ,与 Ni-

脉冲电沉积RE-Ni-W-B-PTFE-Al_2O_3复合镀层性能的研究

高性能复合镀层具有优良的耐磨、耐蚀性能,能满足工业生产对材料性能的要求。研究了脉冲电沉积RE Ni W B PTFE Al2O3 复合镀层的成分、形貌及性能。结果表明:脉冲电流及Al2O3 固体颗粒能明显提高RE Ni W B PTFE Al2O3 复合镀层中W和B的含量;与直流电沉积相比,脉冲电沉积RE Ni W B复合镀层的表面裂纹已明显减小,但裂纹仍存在,当Al2O3 耐磨颗粒及PTFE减摩微粒嵌入RE Ni W B复合镀层中以后,在SEM 400倍下观察,RE Ni W B PTFE Al2O3镀层已不存在裂纹, 而且镀液中Al2O3 颗粒含量越多,晶粒就越细;此外,研究表明,镀液中Al2O3 颗粒含量增加, RE Ni W B PTFE Al2O3 复合镀层镀态硬度增加,磨损率降低。

电沉积 Ni-W-B-SiC 合镀层初探

采用正交法研究了影响电沉积Ｎｉ－Ｗ－Ｂ－ＳｉＣ复合镀层成分的主要因素，确定了最佳镀液组成的工艺参数；探讨了Ｎｉ－Ｗ－Ｂ－ＳｉＣ复合镀层的组织及结构，结果表明镀液组成对复合镀层的表面形貌影响不大；相反，工艺条件对其影响较大；Ｘ射线衍射表明，当镀层中Ｂ的质量百分数为２％时，镀层为晶态结构；当Ｂ的质量百分数在２～３％时为混晶态；当Ｂ的质量百分数大于３％时为非晶态结构．

化学镀Ni-W-B非晶质电阻膜的研究

研究了化学懂Ni-W－B合金的工艺及性能．结果表明，在Ni-B槽液中加入一定量的钨酸钠溶液，不仅能得到含钨、硼的镀层，而且还能提高镀液的沉积速度；Ni-W-B合金层在镀态时为非晶态结构，它的电阻率随钨含量的增加而增大，随镀层厚度的增加而降低．

电沉积Ni-W-B-SiC复合镀层的热力学分析

绘制了Ni-B -H2 O系的电位 -pH图 ,研究和分析了Ni-W -B -SiC复合电沉积中B的沉积机理。研究表明 :由于氢在Fe基金属上沉积存在超电位 ,使得Ni与B将先于H2 而共沉积。

Characteristics of electrodeposited RE-Ni-W-B-B_4C-MoS_2 composite coating

The high temperature oxidation resistance of RE Ni W B B 4C MoS 2 composite coating, the effects of electrodeposition conditions on the morphologies of the coating and the effect of heat treatment temperature on its hardness, abrasion resistance and phase structure were investigated by using scanning electron microscope(SEM), X ray diffractometer, microhardness tester and abrasion machine. The results show that the oxidation degree of RE Ni W B B 4C MoS 2 composite coating is small when the temperature is lower than 700 ℃, but it increases sharply when the temperature is higher than 700 ℃. The hardness of RE Ni W B B 4C MoS 2 composite coating increases with increasing heat treatment temperature, it comes up to the maximum value at 400 ℃,but it decreases gradually if the temperature rises continuously. The most favourable abrasion resistance was attained after RE Ni W B B 4C MoS 2 composite coating being heat treated at 400 ℃. Without heat treating, it is mainly amorphous and partially crystallized, but wholly crystallized after being heat treated at 500 ℃. RE in the composite coating is in the form of CeO 2 and additions of CeO 2 and B 4C can enhance the thermostability of RE Ni W B B 4C MoS 2 composite coating.

非晶态Ni-W-B合金的制备及催化硼氢化钠水解制氢

采用化学还原法合成了非晶态金属硼化物Ni-W-B合金,并用于硼氢化物水解制氢。通过X射线衍射分析（XRD）、扫描电子显微镜（SEM）、X射线能谱分析（EDX）证明,样品Ni-W-B为非晶态的、均匀的球形颗粒,平均粒径约60~70 nm。催化活性实验证明,Ni-W-B合金对Na BH4水解制氢有较好的催化活性;W的含量对催化活性有一定影响,其W与Ni的最佳摩尔比为0.1。影响因素实验证明,Na BH4水解制氢速率与体系温度及催化剂用量呈正比。使用寿命测试证明,经过10次水解循环之后催化剂活性没有明显降低,说明Ni-W-B催化剂有较好的稳定性。

Structure and properties of electrodeposition RE-Ni-W-B-B_4C-PTFE composite coating

The components, surface and cross sectional morphologies, and the effects of heat treatment temperature on phase structure, hardness, abrasion resistance and oxidation resistance of pulse electrodeposition RE-Ni-W-B-B4C-PTFE composite coatings, were all investigated. The results show that W and B contents increase in the RE-Ni-W-B composite coating by using pulse electrodeposition. RE, PTFE and B4C particles can be co-deposited into the Ni-W-B composite coating, but the amount is very little. X-ray diffraction analysis displays that the RE-Ni-W-B-B4C-PTFE composite coating is mainly amorphous, partially crystallized as-deposited, but it turns into crystalline state and PTFE in the coatings will decompose after the heat treatment temperature is higher than 400℃. The hardness of the composite coating increases with increasing heat treatment temperature, it comes up to the highest value at 400℃. The oxidized film mass of the composite coating increases slowly when the oxidation temperature is lower than 500℃, but it increases linearly and sharply after the oxidation temperature is higher than 600℃.

Process and properties of electroless Ni-W-B amorphous electrical resistance film

The process and properties of electroless plating Ni-W-B alloy have been studied. The results show that the deposits containing W and B are obtained, and the deposition rate of the bath is increased with increase of W content when a certain amount of sodium tungstate solution is added in the Ni-B bath. The Ni-W-B alloy is amorphous as deposition and its resistivity increases directly with the increase of W content in the coating, but decreases gradually with increasing the deposit thickness. XRD and SEM show that the distributions of W and B in the Ni-W-B alloy film are very uniform and dispersed without any segregation.

化学镀Ni-W-B非晶质电阻膜的研究

研究了化学镀 Ni-W-B 合金的工艺及性能。结果表明,在 Ni-B 槽液中加入一定量的钨酸钠溶液,不仅能得到含 W、B 的镀层,而且还能提高镀液的沉积速度;Ni-W-B 合金层的电阻率随钨含量的增加而增大,随镀层厚度的增加而降低。

Effects of addition of rare earth on properties and structures of Ni-W-B-SiC composite coatings

The effects of rare earth (RE) on the composition, phase structures, surface morphologies and hardness of electrodeposited RE Ni W B SiC composite coatings were discussed. The results show that W and SiC contents in the coatings increase with the increase of RE in the bath. When RE is added in the coatings, the grains are refined and the trend of formation of amorphous coatings is increased. Moreover, the thermal stability of the RE Ni W B SiC composite coatings is enhanced. The hardness of the coatings is increased with the increase of heat treatment temperature, and it reaches the peak value when heated at 400 ℃. Besides, the hardness of the RE Ni W B SiC coatings is higher than that of the Ni W B SiC coatings.

Electrodeposition and Properties of an Amorphous Ni-W-B Alloy before and after Heat Treatment

To strengthen the properties of Ni-W alloy, dimethylamine borane （DMAB） was added to an alloy Ni-W electrolyte solution and a ternary Ni-W-B alloy was electrodeposited. The electrodeposition, crystallographic structure, surface morphology, heat treatment and corrosion resistance, of the alloy were studied by DSC, XRD, SEM and electrochemical techniques. The results showed that the structure of the alloy was greatly affected by the cooperation of boron compound. DSC experiment combined with X-ray diffractometry indicated that the obtained Ni-W-B alloy was still in amorphous structure although W content in the alloy was decreased by the addition of DMAB. After heat treatment at 400 ℃ for 1 h, the microhardness was increased from 612 to 947 kg.mm^-2 that was com- parative to Cr coating. The appearance of the as-plated coating was in f＇me and slice grains and kept almost no change after heat treatment. In w=0.03 NaC1 solution the as-plated coating presented very good corrosion resistance. After the coating was heat-treated its corrosion resistance was enhanced.

退火前后镍钨硼合金电沉积层的结构与性能

采用电化学技术、 XPS、 DSC、 XRD等方法研究 Ni-W-B合金电沉积及热处理前后合金镀层的结构和显微硬度 .结果表明，在 Ni-W-B合金电沉积过程中伴随着化学沉积镍等过程以及 Na2B4O7在镀层中的夹杂； Ni-W和 Ni-W-B合金电沉积层分别表现为纳米晶结构和非晶态结构；热处理过程中合金电沉积层发生晶粒粗化过程以及 Ni-W-B合金镀层发生新相形成过程，产生 Ni4W和镍硼化物如 Ni2B、 Ni3B等沉淀物； 400℃热处理 2 h后 Ni-W合金镀层有最大的显微硬度达 919.8 kg· mm－ 2，而在 500℃下 Ni-W-B合金有最大的硬度达 1132.2 kg· mm－ 2.