光亮电镀镍添加剂的研究

实验对比研究了糖精、对甲苯磺酰胺、水合三氯乙醛和烯丙基磺酸钠等4种添加剂对电镀镍在光亮度、电流效率、沉积速度、分散能力等方面的影响。结果表明：在20℃和60℃时,对甲苯磺酰胺时沉积速度和电流效率的效果最好;20℃时时甲苯磺酰胺提高分散能力的效果最好。60℃时烯丙基磺酸钠时分散能力的效果较好;20℃时时甲苯磺酰胺对光亮度的综合效果最好,在60℃下糖精对光亮度的提高作用最好。     

组合添加剂用于提高氨基磺酸镍镀液的分散能力和深镀能力

通过在氨基磺酸镍镀液中加入组合添加剂来优化镀液的性能。试验结果表明:使用二苯磺酰亚胺(BBI)0.45～0.60 g/L、烯丙基磺酸钠(SAS)1.30～1.50 g/L、丙炔磺酸钠(PS)0.08～0.10 g/L、羟烷基磺酸钠盐(SSO3)0.02～0.03 g/L、1-(3-磺丙基)吡啶内盐(PPS-OH)0.08～0.10 g/L为组合添加剂，可显著提高氨基磺酸镍镀液的分散能力和深镀能力，其分散能力由原来的21.43%增加到58.29%，深镀能力由原来的40.0%提高至53.5%。BBI、SAS、PS、SSO3和PPS-OH对镀液分散能力和深镀能力的提高均有不同程度的贡献，且是组合添加剂协同作用的结果。      

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/dm²、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。     

掺杂钨丝电沉积铬的工艺研究

为了研究掺杂钨丝（真空镀铬加热元件）表面电解沉积一定厚度（≥100μm）金属铬的工艺,详细考察了不同温度、电流密度、沉积时间等对镀层的影响,并对镀层进行了性能测试。结果表明,最佳工艺条件为：铬酐150—180μg／L,硫酸1．5～1．8g/L,稀土（La^3＋）添加剂0．5-1．5#L,温度为55℃,电流密度为8～10A／dm^2,电镀时间3h。此工艺条件下所得镀层光亮,色泽好,厚度可达100μm,且镀层耐蚀性好,结合力高。     

新型次磷酸钠体系化学镀铜添加剂及其对镀液和镀层性能的影响

目的将聚乙烯吡咯烷酮和二苯胺磺酸钠作为添加剂应用到次磷酸钠化学镀铜体系,并获取最佳应用效果的工艺和条件。方法以PCB环氧树脂板为基材,通过电化学方法研究以聚乙烯吡咯烷酮和二苯胺磺酸钠为添加剂的次磷酸钠体系化学镀铜液及其性能,用称量法研究添加剂对沉积速率的影响,用扫描电镜和X射线能谱仪分析添加剂对沉铜表面质量的影响,用极化曲线法研究添加剂对沉铜表面孔隙率的影响,用交流阻抗法研究添加剂对沉铜表面耐蚀性的影响,同时测定镀液的稳定性。结果在p H=10、温度为65℃的基础液(成分为5 g/L五水硫酸铜、30 g/L次磷酸钠、16 g/L柠檬酸钠、30 g/L硼酸、1 g/L硫酸镍)中,单独加入聚乙烯吡咯烷酮或二苯胺磺酸钠,都能起到很好的沉铜效果。它们的最佳质量浓度分别为20～28mg/L和50～58mg/L。当聚乙烯吡咯烷酮和二苯胺磺酸钠在最佳范围内组合使用时,获得的镀液更稳定,镀层孔隙率低、耐蚀性好、表面均匀,表面铜的质量分数达到95.52%,镀层显粉红色,沉积速率在1.5～2.5μm/h范围内,符合PCB行业要求。结论最佳的化学镀铜液配方和条件为:5 g/L五水硫酸铜、30 g/L次磷酸钠、16 g/L柠檬酸钠、30 g/L硼酸、1 g/L硫酸镍、20～28 mg/L聚乙烯吡咯烷酮、50～58 mg/L二苯胺磺酸钠,pH=10,温度65℃。研究成果对电镀铜添加剂的开发和应用有重要意义。     

印刷电路板上化学镀钯工艺研究

采用L9(34)混合正交体系,系统地研究复合络合剂-乙二胺、乙二胺四乙酸二钠和丙烯酸在不同工艺参数和不同添加配比情况下对化学镀钯质量的影响,以镀层的光亮度,镀液的稳定性和沉积速度为评价指标,筛选出最佳的化学镀钯添加剂为:乙二胺0.2mol/L,乙二胺四乙酸二钠0.01mol/L,丙烯酸0.3mol/L,pH值8。研究结果表明,优化后的化学镀钯镀液稳定性高、沉积速度快、钯膜与基体镍镀层结合力强、钯镀层光亮性好。     

尼龙66复合镀电磁屏蔽织物

目的探究尼龙66化学镀最佳粗化工艺,优化次亚磷酸钠化学镀铜工艺,比较在相同工艺条件下化学镀镍-铜及化学镀铜-镍工艺对织物电磁屏蔽效能的影响。方法将经过稀盐酸/乙酸水溶液以及稀盐酸/乙酸乙醇溶液粗化后的尼龙66织物化学镀镍,用扫描电镜观察镀层效果,对比两种粗化方案,用化学镀铜沉积速率及质量损失率反映化学镀镀覆效果,探索出次亚磷酸钠的最佳镀铜配方,确定次亚磷酸钠化学镀铜的最佳工艺条件。用法兰同轴测试化学镀铜、化学镀镍及经过化学镀镍后镀铜和化学镀铜后镀镍的电磁屏蔽效能。结果稀盐酸/乙酸水溶液粗化后,织物镀层易脱落;稀盐酸/乙酸乙醇溶液粗化后,镀层覆着力强。以次亚磷酸钠为还原剂的最佳镀铜工艺为:硫酸铜20 g/L,硫酸镍8 g/L,次亚磷酸钠70 g/L,硼酸35 g/L,p H10.2～10.6,时间20min,温度75℃。化学镀铜后化学镀镍得到的织物屏蔽效能达70d B。结论稀盐酸/乙酸乙醇溶液粗化效果最佳,比使用稀盐酸/乙酸水溶液处理的镀层更均匀致密。化学镀镍所得镀层为非晶态物质,次亚磷酸钠化学镀铜所得镀层为晶态物质。化学镀铜后镀镍织物镀层更为致密。在相同工艺条件下,化学镀铜-镍的质量增加率大于化学镀镍-铜,屏蔽效果优于化学镀铜、化学镀镍-铜。     

以酒石酸钾钠为主络合剂的化学镀铜添加剂研究

研究了以酒石酸钾钠为主络合剂的化学镀铜添加剂,讨论了甲醇、亚铁氰化钾、2,2′-联吡啶三种添加剂对镀液稳定性、镀层质量、沉积速率的影响,通过正交试验确定了各添加剂的用量。实验结果表明:在酒石酸钾钠为主络合剂的化学镀铜液中添加14mL/L甲醇、30mg/L亚铁氰化钾和5mg/L 2,2′-联吡啶,化学铜沉积30min后,沉积速率可达到4.6μm/h。在此工艺条件下,镀层呈现带光泽的淡粉红色,镀液稳定性佳,镀层附着力好。     

光亮锡镍合金电沉积新工艺

在研究碱性锡镍合金的电沉积过程中,讨论了镀液中各成分的含量、电镀工艺条件的改变及添加剂对锡镍合金镀层成分和外观的影响规律。获得了内应力小,同基体结合力好,表面光亮、平整致密,具有高耐蚀性的合金镀层。优化工艺为:SnCl215g/L,NiSO4.6H2O 35g/L,K4P2O7.3H2O 260g/L,NH4Cl 12g/L,糖精2g/L,十二烷基磺酸钠2.5g/L,对苯二酚1.5g/L,pH 8.5,Dk1.5A/dm2,温度30℃。     

新型铜锡合金电镀添加剂的制备

目的制备一种电镀铜锡合金添加剂,利用此种添加剂制得白亮并且综合性能良好的铜锡合金镀层。方法基础镀液组成为:焦磷酸钾250 g/L,焦磷酸铜16 g/L,焦磷酸亚锡12 g/L。工艺条件为:pH 8.5,室温,电流密度0.3 A/dm~2,电镀时间5 min。以此为基础,设计正交试验,以镀层60°光泽度作为判定标准,优选出电镀添加剂的最佳配方。利用百格刀、维氏硬度计、材料表面性能综合测试仪、盐雾试验箱对最佳配方制备的镀层的附着力、表面硬度、摩擦系数、耐蚀性能等进行分析,利用SEM、XRD对其表面形貌及物相进行分析。结果经过正交试验优选出的最佳添加剂配方为:8×10~(-3) g/L聚二硫二丙烷硫磺酸钠(SPS),8×10~(-3) g/L聚乙烯亚胺烷基盐(PN),8×10~(-4) g/L 2-巯基苯并咪唑(M)。采用该添加剂配方,在上述基础镀液及工艺条件下,可获得全范围白亮Hull槽试片。该镀层60°光泽度达到269.7,表面平整,附着力的ISO等级为2,维氏硬度为154.47HV0.2,摩擦系数为0.2,盐雾试验中超过72 h无腐蚀。结论复配添加剂可以制备出光泽度较高的银白色镀层,且镀层结合力好,硬度、耐磨性以及耐腐蚀性都较高,可以满足工业要求。镀层表面平整,物相为Cu_6Sn_5以及Cu_(13.7)Sn。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。