工艺参数对Ni-SiC纳米复合镀层沉积速率的影响

用电沉积的方法在铜表面制备了Ni-SiC纳米复合镀层,研究了不同的工艺参数,包括阴极电流密度、镀液中纳米SiC悬浮量、镀液pH值、镀液温度和搅拌速度对复合镀层的沉积速率的影响。结果表明：在实验电流范围内,镀层的沉积速率随着阴极电流密度的增大呈线性上升的趋势;随着镀液中纳米颗粒悬浮量、镀液pH值及搅拌速度的增大而增大,当达到一定值时,又开始下降;随着镀液温度升高,逐步降低。最佳参数为：不烧焦镀层前提下的最大电流,纳米颗粒体积质量为5g／L,pH值3．5—4．0,温度30℃,搅拌速度为中高速。     

Ni-P/Al_2O_3复合镀层性能的表征与测试

为了提高镀层的耐磨性和硬度,在45碳钢基材上实施Ni-P/Al2O3化学复合镀,使纳米Al2O3微粒均匀分布于Ni-P基体中.研究了化学复合镀工艺条件和镀液组分对镀层性能的影响.镀件的耐蚀性实验和XRD分析表明:当硫酸镍25 g/L,次亚磷酸钠30 g/L,纳米Al2O3微粒加入量为5 g/L,乳酸20 mL/L和柠檬酸5 g/L,在pH=5.5,施镀温度为(85±2)℃,获得的Ni-P/Al2O3复合镀层表面光滑、胞状物致密,镀层的耐腐蚀性较高、硬度可达600HV,有利于得到综合性能较高的镀层.     

Ni-P-纳米TiO2化学复合镀层的制备

采用化学复合镀在40CrNi钢基体上制备Ni-P-纳米TiO2复合镀层,研究了乳酸,柠檬酸、乙酸钠以及表面活性剂对镀层的沉积速度和显微硬度的影响,并通过正交试验,优化了工艺参数。结果表明:当乳酸的体积分数为3%、柠檬酸的质量浓度为25 g/L、乙酸钠的质量浓度为20 g/L、表面活性剂为阴离子型时,镀层具有优良的性能,镀速达到了11.55μm/h,镀层镀态显微硬度为550 HV。     

复合化学镀Ni—P—SiC工艺研究

通过正交试验对复合化学镀Ni—P—SiC工艺参数进行了优化，并确定了镀液的最佳温度、搅拌速度、酸碱度及SiC微粉的加入量，最后对镀层性能进行了测试。     

复合化学镀Ni-P-SiC工艺研究

通过正交试验对复合化学镀Ni-P-SiC工艺参数进行了优化,并确定了镀液的最佳温度、搅拌速度、酸碱度及SiC微粉的加入量,最后对镀层性能进行了测试.     

Ni-Zn-P三元合金沉积速率的研究

Ni-Zn-P合金具有优良的化学、物理性能,已在工业上广泛应用.但是对Ni-Zn-P合金沉积速率的研究,目前还未见报道.在确定化学镀Ni-Zn-P镀液组成的条件下,研究工艺参数如pH值、温度、主盐浓度、施镀时间和稳定剂对沉积速率的影响,并且用点滴实验法对合金镀层的耐蚀性进行测试.结果表明:在其它条件不变的情况下,控制pH值为9,温度98℃,NiSO4浓度35g/L,施镀2h,并加少量稳定剂,能获得800～1000mg/(dm2·h)的镀速,并且镀层有良好的耐蚀性.     

Al_2O_3陶瓷化学镀Ni-P工艺研究

采用化学镀方法在Al2O3陶瓷表面施镀Ni-P合金镀层,借助SEM、XRD等分析手段对镀层结构进行了表征,研究主盐浓度、还原剂浓度、粗化时间、镀液pH值、稳定剂以及水浴温度对镀层形貌、相组成以及镀层与Al2O3陶瓷基体结合强度的影响规律.结果表明,主盐NiSO4的浓度为25 g/L、NaH2PO2的浓度为30 g/L、pH=5、粗化时间为30 min、水浴温度为92℃时,Ni-P合金镀层与Al2O3陶瓷基体的拉伸载荷最高为49.9 N;显微组织观察发现,Ni-P合金镀层显微组织为胞状结构,胞状物排列紧密,无缝隙和孔洞,具有非晶态特征,镀层断口形貌为镀层从基体与镀层分界面被"揭开"方式断裂.     

Ni-P-Cr_2O_3化学复合镀工艺及稀土的影响

研究了Ni P Cr2 O3 化学复合镀工艺及稀土对复合镀工艺及第二相粒子沉积量的影响 .结果表明 :Ni P Cr2 O3 复合镀的最佳工艺参数为 :Cr2 O3 :10 g/L、温度 :86± 2℃ ,pH值 :4 .7± 0 .1.此条件下镀速为15～ 16 μm/h ;沉积量为 2 4 .2 % .稀土能与Ni、P共沉积 ,对镀层起到微合金化的作用 ,同时提高了第二相粒子的沉积量 .当稀土的加入量为 2 0～ 2 5mg/L时 ,Cr2 O3 的沉积量增加了 1倍多 .     

化学镀Ni-Zn-P合金预处理及耐蚀性能研究

对化学镀Ni-Zn-P合金的镀前预处理方法进行了研究,通过单因素实验方法研究了主盐硫酸镍浓度、主盐硫酸锌浓度、络合剂乳酸浓度、还原剂次亚磷酸钠浓度、镀液温度、pH值、施镀时间对镀层耐蚀性的影响,观察镀层的微观形貌、研究了镀层的组成成分及晶相结构。结果表明:预镀薄镍层是化学镀Ni-Zn-P合金比较适宜的前处理方法,硫酸镍20g·L~(-1)、硫酸锌6g·L~(-1)、乳酸20mL·L~(-1)、次亚磷酸钠24g·L~(-1)、镀液温度80℃、pH值5、时间2h,镀层耐蚀性能良好。镀层为致密的颗粒结构,含锌5.06%(质量分数),镀层为晶态结构。     

SiC在Ni-P-SiC化学复合镀层中共析因素研究

在实现Ni-P-SiC化学复合镀时，影响分散剂SiC在镀层中共析的因素很多，作者选择其中几个基本因素如分散剂的添加量、分散剂粒子的大小，镀液的搅拌速度、试验片的定位角度、镀层析出速度等进行了研究，在充分的实验基础上，明确了这些因素对镀层中SiC共析量的影响并探讨了其原理。     

Ni—P—MoS2与Ni—P—CaF2化学复合镀层自润滑性能的对比研究

为对比研究Ni—P—MoS2和Ni—P—CaF2两种化学复合镀层的自润滑性能,以45钢为基体,制备了Ni—P-MoS2和Ni-P-CaF2复合镀层并研究了镀层的施镀工艺,详细介绍了caF2、MoS2固体自润滑微粒镀前预处理技术,通过金相显微镜、x射线荧光仪对复合镀层的表面形貌和结构等性能进行了分析,在PLINT微动疲劳试验机上对复合镀层的自润滑性能进行了测定。结果表明：所述复合镀层的工艺配方能够可靠完成复合镀层的施镀,常温下,Ni-P-MoS2复合镀层具有优异的自润滑性能,且优于常温下的Ni—P—CaF2复合镀层。     

Electroless copper-phosphorus coatings with the addition of silicon carbide （SiC） particles

Cu-P-silicon carbide(SiC)composite coatings were deposited by means of electroless plating.The effects ofpH values,temperature,and different concentrations of sodium hypophosphite(NaH2PO2·H2O),nickel sulfate(NiSO4·6H2O),sodium citrate(C6H5Na3O7·2H2O)and SiC on the deposition rate and coating compositions were evaluated,and the bath formulation for Cu-P-SiC composite coatings was optimised.The coating compositions were determined using energy-dispersive X-ray analysis(EDX).The corresponding optimal operating parameters for depositing Cu-P-SiC are as follows:pH 9; temperature,90℃; NaH2PO2·H2O concentration,125 g/L; NiSO4·6H2O concentration,3.125 g/L; SiC concentration,5 g/L; and C6H5Na3O7·2H2O concentration,50 g/L.The surface morphology of the coatings analysed by scanning electron microscopy(SEM)shows that Cu particles are uniformly distributed.The hardness and wear resistance of Cu-P composite coatings are improved with the addition of SiC particles and increase with the increase of SiC content.     

化学镀法制备钴包覆碳化硅复合粉末的研究

采用化学镀法制备钴包覆碳化硅复合粉末,通过研究化学镀过程中钴盐浓度、还原剂浓度、络合剂浓度、缓冲剂浓度、温度以及pH值等因素对沉积速率的影响规律,得到化学镀钴的优化条件。利用XRD、SEM和EDAX等测试手段对该复合粉末的组分及形貌进行了表征。实验和表征结果表明,当硫酸钴浓度为30～50g/L,次磷酸钠浓度为40g/L,柠檬酸钠浓度为60～70g/L,控制温度为50～70℃以及调节pH值等于8时,镀层沉积速度较快,所得粉体表面被钴均匀包覆。     

Effects of Surfactants SDS and CTAB on Ni-SiC Deposition

The influences of surfactant type and concentration on the content and uniformity of SiC particles in Ni-SiC deposit were studied in this paper. The electrochemical behavior of preparing Ni-SiC composite coating was investigated using the cyclic voltammetry method. Then the impact of surfactants on the deposition potential of Ni-SiC coating was analyzed. Electrochemical studies showed that the cathode overvoltage increases gradually with increasing SDS (Sodium dodecyl sulfate) concentration. The CV curve showed the shift towards a lower current at a given potential with increasing SDS concentration. Ni-SiC composite coatings were prepared by electrodeposition. The experimental results show that the dispersion of 40nm SiC in Ni-SiC coating obtained in the electrolyte containing SDS is superior that containing CTAB (cetyltrimethyl ammonium bromide). CTAB increases the content of 40 nm SiC particles in the Ni-SiC coating, but the uniformity of 40 nm SiC particles in Ni-SiC composite coating is poor. SiC particles are still agglomerated. Compared with the anionic surfactant SDS and the cationic surfactant CTAB, surfactant SDS makes the particles better dispersed. But the contribution of surfactant SDS for co-deposition amount of SiC particles is negligible. The cationic surfactant CTAB can effectively improve the suspension performance of SiC particles and promote the co-deposition of SiC particles and metallic nickel. But there is still some reunion of SiC.     

Reactive Processing and Mechanical Properties of Al/SiCP Composite

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硫脲对Ni-P镀层腐蚀行为的影响

在镀液中添加硫脲,分析了硫脲对Ni-P镀层沉积速度、表面形貌、孔隙率等的影响,并通过极化曲线和交流阻抗测试了硫脲对Ni-P镀层腐蚀性的影响。结果表明,当镀液中添加1 mg/L硫脲时,镀层的沉积速率加快,腐蚀速率增大。这主要是因为镀液添加硫脲后,镀层的孔隙率加大,促进了腐蚀介质渗入到基体表面,增加了腐蚀微电池的数量,形成了大阴极(镀层)-小阳极（基体）腐蚀微电池,使自腐蚀电流密度增大,电荷转移电阻减小。当镀液中添加硫脲质量浓度大于3 mg/L时,镀液被毒化,无法施镀。     

Fabrication of W@Cu composite powders by direct electroless plating using a dripping method

A direct electroless copper (Cu) coating on tungsten powders method requiring no surface treatment or stabilizing agent and using glyoxylic acid (C₂H₂O₃) as a reducing agent was reported. The effects of copper sulfate concentration and the pH of the plating solution on the properties of the prepared W@Cu composite powders were assessed. The content of Cu in the composite powders was controlled by adjusting the concentration of copper sulfate in the electroless plating solution. A uniform, dense, and consistent Cu coating was obtained under the established optimum conditions (flow rate of C₂H₂O₃ = 5.01 mL/min, solution pH = 12.25 and reaction temperature 45.35 °C) by using central composite design method. In addition, the crystalline Cu coating was evenly dispersed within the W@Cu composite powders and Cu element in the coating existed as Cu0. The formation mechanism for the W@Cu composite powders by electroless plating in the absence of surface treatment and stabilizing agent was also proposed.     

化学沉积法制备Ni-P-SiC复合镀层的研究

研究了在碳钢基材表面进行化学沉积Ni-P-SiC复合镀层的工艺和条件,对镀层的成分进行了扫描分析,对镀层的金相组织进行了观察分析;结果表明SiC硬质纳米粒子嵌入,使Ni-P合金基质产生沉淀强化,使镀层硬度增加.通过对磨实验和腐蚀实验证明,复合镀层可使碳钢零件耐磨性能提高3倍,可使碳钢零件耐蚀性能提高4倍,有效地延长了钢铁零件的使用寿命.     

Mechanism and Microstructure of Electroless Ni-Fe-P Plating on CNTs

Electroless Ni-Fe-P alloy plating on the surface of CNTs was carded out with a bath using citrate salt and lactic acid as complex agents. We proposed a chemical reaction mechanism. The morphology, structure and chemical composition of the Ni-Fe-P/CNTs were studied with the aid of a scanning electronic microscope （SEM）, X-ray diffraction （XRD） and an energy-dispersive X-ray spectral analysis （EDS）. The results show that through a correct pre-treatment and electroless plating, Ni-Fe-P/CNTs composite particles can be obtained. The optimum electroless plating parameters of 35-42℃ and pH of 8.5-9.7 were achieved. The as-plated Ni-Fe-P alloy is amorphous. After a heat treatment at 500℃ for 90 min in H2, the coating is transformed into crystalloid Ni3E Fe2NiP and （Fe,Ni）3R The Ni-Fe-P alloy coating on the surface of CNTs is smooth and unique. The amount of Ni on the surface （mass fraction） of the Ni-Fe-P/CNTs composite particles is 29.13%, that of Fe 3.19% and that of P 2.28%.     

Thermodynamic analysis of the preparation process of EB-PVD SiC coating

The process of preparing SiC coating by electron beam-physical vapor deposition (EB-PVD) was discussed from viewpoint of thermodynamis. Results show that within the temperature range of 2 700–3 300 K, the ratio of SiC in the SiC coating doesn’t change much and keeps around 0.7. Purity of the as-deposited SiC coating is not high. To improve the purity of the SiC coating, the SiC ingot is required to not be, necessary in full density but be fine-grained.