Ni-P非晶镀层的电刷镀制备工艺及其性能的研究

在不同刷镀工艺参数下制备了Ni-P合金非晶电刷镀镀层，研究了工艺参数对镀层沉积速率、镀层组织与性能的影响，最佳工艺条件下镀层的耐磨性以及热处理后镀层性能的变化等。结果表明，在电刷电压为12V，阳极运动速度为10m／min条件下，镀层可获得最佳的组织与性能，Ni-P非晶电刷镀层经热处理后由于Ni3P的析出，使镀层硬度提高，从而提高了镀层的耐磨性。     

Ni-Sn-P复合镀层的组织结构与抗垢性能研究

采用XRD测试、硬度测试、接触角测量、表面自由能计算和抗垢能力测试等方法，研究热处理对Ni-Sn-P复合镀层组织结构和抗垢性能的影响，以及Sn含量对镀层抗垢性能的影响。结果表明，经热处理后Ni-Sn-P复合镀层结构由非晶态转变为晶态。300 ℃热处理的Ni-Sn-P复合镀层显微硬度达1072.4 HV，相比Ni-P镀层其硬度明显提高。当Sn含量为2 g/L时，Ni-Sn-P复合镀层具有最佳的抗垢性能，复合镀层的接触角为120.2°，且具有较低的表面能15 mJ/m²。Ni-Sn-P复合镀的污垢附着率显著降低，抗垢性能相比未处理的Q235碳钢基体和Ni-P镀层分别提高55%和46%。Sn颗粒的加入，提高了镀层的硬度和疏水性，但是随着Ni-Sn-P复合镀层中Sn含量的增加，复合镀层的抗垢性能逐渐下降。     

螺杆压缩机壳体(HT200)内腔化学镀Ni-P合金

以材料为HT200的螺杆压缩机壳体为对象，在实验的基础上，分析化学镀Ni-P合金过程中，络合剂种类、稳定剂的含量、pH值、活化处理及后处理等对镀层耐蚀性、含磷量、结合力、表面形貌等的影响规律。对镀层的物理、化学性能检测结果表明，获得的镀层性能良好。     

高速电喷镀纳米复合镀层组织与性能研究

采用高速电喷镀工艺制备纳米Ni／PTFE复合镀层。研究了电流密度、镀液中纳米PTFE含量等工艺参数对镀层性能的影响。研究结果表明，提高电流密度可显著提高复合镀层的沉积速率、镀层与基体的结合强度以及镀层的耐腐蚀性：镀层与基体的结合强度随镀液中PTFE的加入量的改变而变化，当加入量为10ml／L时，镀层经30次热震试验后，镀层无明显剥落：Ni与纳米PTFE共沉积可显著改善镀层的耐腐蚀性能。     

电沉积非晶态铬镀层的组织与性能

用电沉积方法制备了非晶态铬镀层，用X射线衍射仪分析了镀层的相结构，对镀层的组织与性能以及热处理对镀层组织与性能的影响进行了研究。结果表明，非晶态铬镀层的硬度值约为969HV0．025，热处理后由于Cr7C3相的析出使硬度最高可升至1345HV0．025，非晶态铬镀层表现出良好的耐磨性和耐蚀性能，明显优于普通晶态铬镀层。热处理后，镀层与基体的结合力也有明显提高。     

镍及其镍磷非晶态合金电刷镀镀层性能的分析

利用扫描电镜，能谱分析仪，ＭＭ－２０００型试验机及ＭＩＲＯＭＥＴⅡ数显式显微硬度计对镀层的硬度，摩擦磨损性能及对耐蚀性能进行了分析测试，并研究了热处理对其组织结构及性能的影响，从而分析比较各种镀层性能及差异，在此基础上确定了进口汽车内燃机缸套修复的最佳镀层，为镀层的应用提供依据。     

化学镀钴-磷-氧化锆复合镀层的研究

采用化学镀法制备钴-磷-氧化锆复合镀层，并研究了PH值、温度、氧化锆的加入量、氧化锆的粒度和后处理等制备工艺条件对沉积速率、镀层的空隙率、硬度争性能的影响。试验结果表明，制备钴-磷-氧化锆复合镀层的最佳工艺条件为85℃-90℃、PH值9左右，采用空气搅拌或电磁射觉拌。加入细的ZrO2颗粒不仅可以细化镀层的组织结构，而且还可以提高镀层硬度等性能。所获得的复合镀层经400℃热处理后，显微硬度还可进一步提高。     

机械镀镀层制备及性能研究

用325目电炉球状锌粉并经冷扎处理为片状锌粉分别制备了镀层Ⅰ和镀层Ⅱ，通过扫描电子显微镜(SEM)对该镀层的形貌分析、中性盐雾试验、附着力测试等手段对该镀层的性能进行了研究.结果表明，片状锌粉用于机械镀，锌粉活性明显增强，镀覆效率提高；片状锌粉层层叠加，镀层的耐腐蚀性、表面密封性、可钝化性、镀层光亮度等均有明显改善，具有较好的工业应用价值.      

磷含量在化学镀层中对其性能的影响

采用酸性化学镀镍－磷合金电解液，通过改变不原剂浓度，制备了一系列不同磷含量的镍－磷合金镀层，以研究其中磷含量对镀层性能的影响。实验结果表明，镀层耐蚀性，硬度等性能与磷含量有直接关系，文他这种关系。     

氯化物电镀Zn—P合金的研究

研究了Ｚｎ－Ｐ合金电镀液组成及工艺条件对镀层含磷量的影响，在最佳工艺参数条件下，可得到磷的质量分数为０．１％左右的Ｚｎ－Ｐ合金镀层。对镀液、镀层性能进行了测试，实验证明经银白色钝化后的Ｚｎ－Ｐ合金镀层的耐蚀性能是纯锌镀层的２倍以上。     

Effect of initial deposition behavior on properties of electroless Ni–P coating on ZK60 and ME20 magnesium alloys

The composition of magnesium alloys is greatly associated with initial deposition behavior of electroless Ni–P coatings. Thus, the initial deposition behavior of electroless Ni–P coatings on ZK60 and ME20 alloys was investigated. The results indicated that differences in the alloy compositions significantly influenced the initial deposition process and the adhesive strength, corrosion resistance, and crystal structure. The initial deposition of coatings on ZK60 and ME20 alloys preferentially occurred on the precipitates. The precipitates in ZK60 alloy had higher chemical activity after HF activation and controlled the initial deposition rate of the coating. The initial deposition rate of the coating on ME20 alloy mainly depended on the density of the MgF₂ film formed by HF activation rather than on the precipitates. Owing to differences in the initial deposition process, the coating on ZK60 alloy had higher adhesive strength and better corrosion resistance than that on ME20 alloy. The coatings on ZK60 and ME20 alloys mainly had crystalline structures, and the coating on ME20 alloy had also a slight microcrystalline structure.     

低碳钢表面化学镀Ni-Zn-P合金镀层的沉积行为及沉积机理

目的通过研究低碳钢表面碱性化学镀Ni-Zn-P合金镀层的沉积行为及其沉积机理,对化学镀Ni-Zn-P有进一步认识。方法采用碱性化学镀方法,改变施镀时间在低碳钢表面化学镀Ni-Zn-P合金镀层。使用扫描电镜观察合金镀层的表面和断面形貌,用电子能谱仪分析镀层表面和断面成分。结果化学镀Ni-Zn-P合金镀层的形成过程是:固液界面形成原子团→原子团在能量较高的地方择优沉积→原子团累积生长→向周围延伸扩展→覆盖整个机体→形成完整镀层→均匀叠加生长。试样表面成分检测表明,施镀1~3 s内表面出现Ni元素,Ni质量分数在3 min时达到最大值75.93%,此后维持相对稳定;施镀1 min时表面出现P,P质量分数随施镀时间延长而逐渐增加,在30 min时达到最大值12.03%,此后维持相对稳定;施镀5 min时表面出现Zn,随着施镀时间的延长,Zn沉积量变化不大。表面和断面成分分析表明,化学镀Ni-Zn-P合金镀层的沉积过程不是Ni,Zn,P三种元素同时沉积,而是Ni优先沉积,然后Ni和P共沉积,最后Ni,Zn,P三种元素共同沉积。根据能斯特方程算得沉积电位E_(Ni~2+/Ni)=-0.337 V,E_(Zn~2+/Zn)=-0.906 V,两者的沉积电位相差较大,说明该化学镀条件下不能发生合金共沉积。结论推测化学镀Ni-Zn-P合金镀层是催化诱导还原反应沉积机理,即在镍还原诱导下引发的Zn共沉积。     

Comparative study on corrosion protection properties of electroless Ni‐P‐ZrO2 and Ni‐P coatings on AZ91D magnesium alloy

Electroless Ni‐P‐ZrO₂ and Ni‐P coatings on AZ91D magnesium alloy were prepared, and their corrosion protection properties were compared in this paper. The potentiodynamic curves and electrochemical impedance spectroscopy (EIS) of the coated magnesium alloy in 3.5% NaCl solution showed that the corrosion performance of Ni‐P‐ZrO₂ composite coating was superior to that of Ni‐P coating. The same conclusion was obtained with salt spray and immersion tests. The corrosion morphologies of two kinds of coatings with various immersion time intervals in 3.5% NaCl solution indicated that most corrosion products concentrated on the nodules boundaries of Ni‐P coating and blocked corrosion pit was the main corrosion form. For the Ni‐P‐ZrO₂ coating, tortuous nodules boundaries were not the weak sites of the coating and corrosion initiated from the nickel phosphor alloy around the nanometer powders. Open corrosion pits occurred on the composite coating surface, and the coating was corroded gradually. Thus, the Ni‐P‐ZrO₂ coating exhibited better corrosion protection property to magnesium alloy substrate than Ni‐P coating.     

Ni-P合金镀层初期沉积行为的电子探针研究

用电子探针方法分析了在不同组织的碳钢基体上电沉积Ni-P合金的初期沉积行为。结果表明，Ni-P合金在渗碳体基体表面和晶界上优先沉积，沉积初期的镀层分布是不均匀的。消除镀层初期不均匀分布的有效途径是对基本组织进行均匀化处理。     

激光功率对激光熔覆WCP/Ni基金属陶瓷涂层的组织与磨损性能的影响

研究了3种不同功率(1．8kW、2．2kW、2．6kW)对激光熔覆WCp／Ni基金属陶瓷涂层的组织与磨损性能的影响．选择合适的激光功率(2．2kW)，可以获得WCp均匀分布并与基体合金结合良好的WCp／Ni涂层．激光熔覆过程中WC颗粒与基体合金界面间发生了扩散反应溶解，导致未熔WC颗粒周围形成了块状的富W碳化物，功率较高时更加明显．激光熔覆WCp／Ni基涂层由未熔WC颗粒，块状或枝晶状的富W碳化物，杆状的富Cr碳化物以及其间的γ枝晶固溶体及其共晶组织所组成．不同激光功率下的WCp／Ni涂层的显微硬度与耐磨性均远高于Ni60涂层，其中2．2kW功率的WCp／Ni基涂层的显微硬度最高，耐磨性最好。     

氯离子浓度对Ni-P合金涂层失效过程影响的SECM实验和COMSOL模拟研究

目的发展具有空间分辨的腐蚀电化学研究方法。方法用电沉积方法在铜基体上制备Ni和Ni-P涂层,应用扫描电镜和XRD检测涂层表面形貌和晶体结构,采用扫描电化学显微镜(SECM)研究Ni和Ni-P涂层在不同浓度Na Cl溶液中的失效行为,并结合COMSOL多物理场软件建立二维和三维模型,模拟量化活性点大小和反馈机制。结果低浓度Cl-对于纯Ni涂层具有活化作用,增加Cl-浓度会促进腐蚀发生。Ni-P合金涂层在低浓度Na Cl溶液中,短时间内保持良好的稳定性,浸泡6 h后,低P合金涂层出现典型的活性点和腐蚀产物,而高P合金涂层在浸泡24 h后出现腐蚀产物和活性区域。0.1 mol/L的Na Cl溶液促进低P合金涂层局部腐蚀的发生,而涂层在0.3 mol/L Na Cl溶液中则以发生均匀腐蚀为主。逼近曲线及其模拟结果表明,腐蚀产物对于Fc Me OH的电化学过程完全失活,而新鲜Cu表面对Fc Me OH氧化还原过程受扩散控制。三维模拟结果显示,低P合金涂层失效过程中活性点大小接近10μm。结论 Ni和Ni-P合金涂层的失效过程中活性点的形成、腐蚀产物的生成和累积过程与SECM面扫描图谱中正负反馈效应相关,Cl-促进腐蚀发生,其浓度影响腐蚀类型。COMSOL多物理场模拟明确反馈效应与探针和基底的距离有关,Ni-P涂层失效活性点大小在微米级。     

Effect of Heat Treatment on Structure and Electrochemical Properties of Electro-deposited Ni-P Amorphous Alloy

ELECTROCHEMICAL deposition of Ni-P alloy iswidespread due to the unique physical,chemical andmechanical properties of these materials'11.And moreand more emphasize were laid on the study ofelectrochemical deposition of amorphous Ni-P alloybecause of its unique corrosion resistance.However,the detail reports about the relation of heat treatmenttime and the electrochemical behavior of amorphousNi-P alloy are rare.In this article,the influences of heattreatment time on the structure and t…     

Formation of NiAl Intermetallic Compound by Cold Spraying of Ball-Milled Ni/Al Alloy Powder Through Postannealing Treatment

Ni/Al alloy powders were synthesized by ball milling of nickel-aluminum powder mixture with a Ni/Al atomic ratio of 1:1. Ni/Al alloy coating was deposited by cold spraying using N₂ as accelerating gas. NiAl intermetallic compound was evolved in situ through postspray annealing treatment of cold-sprayed Ni/Al alloy coating. The effect of annealing temperature on the phase transformation behavior from Ni/Al mechanical alloy to intermetallics was investigated. The microstructure of the mechanically alloying Ni/Al powder and NiAl coatings was characterized by scanning electron microscopy and x-ray diffraction analysis. The results show that a dense Ni/Al alloy coating can be successfully deposited by cold spraying using the mechanically alloyed powder as feedstocks. The as-sprayed alloy coating exhibited a laminated microstructure retained from the mechanically alloying powder. The annealing of the subsequent Ni/Al alloy coating at a temperature higher than 850 °C leads to complete transformation from Ni/Al alloy to NiAl intermetallic compound.     

Electrodeposition and corrosion resistance of Ni–P–TiN composite coating on AZ91D magnesium alloy

In order to improve the corrosion resistance and microhardness of AZ91D magnesium alloy, TiN nanoparticles were added to fabricate Ni–P–TiN composite coating by electrodeposition. The surface, cross-section morphology and composition were examined using SEM, EDS and XRD, and the corrosion resistance was checked by electrochemical technology. The results indicate that TiN nanoparticles were doped successfully in the Ni–P matrix after a series of complex pretreatments including activation, zinc immersion and pre-electroplating, which enhances the stability of magnesium alloy in electrolyte and the adhesion between magnesium alloy and composite coating. The microhardness of the Ni–P coating increases dramatically by adding TiN nanoparticles and subsequent heat treatment. The corrosion experimental results indicate that the corrosion resistance of Ni–P–TiN composite coating is much higher than that of uncoated AZ91D magnesium alloy and similar with Ni–P coating in short immersion time. However, TiN nanoparticles play a significant role in long-term corrosion resistance of composite coatings.     

化学沉积Ni—Mo—P合金镀层的组织与耐蚀性能

对化学镀Ni-P和Ni-Mo-P 合金的表面形貌及性能进行了比较分析，表明Ni-Mo-P合金由于钼的加入，改变了镀层的组织结构，进而提高了镀层的硬度及耐蚀性。