纳米颗粒增强Ni基复合镀渗层的腐蚀与

采用复合镀渗工艺,对316L不锈钢表面刷镀的两种纳米陶瓷颗粒(非晶纳米SiO2(n-SiO2)和纳米SiC(n-SiC)颗粒)增强的复合镀层进行双辉Ni-Cr-Mo-Cu多元共渗处理,成功地在316L不锈钢表面制备了纳米颗粒增强Ni基合金层。利用XRD、SEM和TEM对两种复合镀渗层的微观组织进行观察,采用极化曲线、电化学阻抗谱(EIS)和冲刷腐蚀试验对两种复合镀渗层的耐蚀性和耐冲蚀性能进行研究。对两种颗粒增强的复合镀渗层的微观组织分析结果表明:在双辉多元共渗工艺(1000℃)条件下,电刷镀含n-SiO2颗粒的复合镀渗层中的SiO2颗粒仍保持非晶态;而电刷镀含n-SiC颗粒的复合镀渗层中的SiC颗粒已完全分解并与基体合金元素发生反应,导致在晶内析出三元硅化物Cr6.5Ni2.5Si和沿晶界析出碳化物Cr23C6。在3.5%NaCl(质量分数,下同)溶液中的电化学腐蚀实验结果表明:SiO2颗粒增强的复合镀渗层存在明显的钝化区,点蚀电位和维钝电流密度与Ni基合金渗层的十分接近,而电刷镀含SiC颗粒增强的复合镀渗层处于活化状态,但其耐蚀性能仍略强于不锈钢;两种复合镀渗层的EIS图谱均呈现单容抗弧特征,与Ni基合金渗...     

纯铜离子渗镀钛层的耐蚀性

采用加弧辉光离子渗镀技术, 实现了在纯铜表面形成均匀的渗镀钛层. 用电化学测试技术对渗镀层在0.5moL/LH2SO4溶液中的耐蚀性进行了对比试验研究. 结果表明渗镀钛层的耐蚀性能大大提高, 与钛板相当, 并对渗镀层钛浓度的分布、渗镀层显微硬度、渗镀层相的结构进行了测定.     

多层复合渗镀TiN耐蚀性的研究

采用双层辉光渗金属技术,在碳钢表面形成具有扩散层和沉积层的TiN复合渗镀层.对复合渗镀、PVD以及复合渗镀 PVD三种工艺制备的TiN层表面形貌、成分及在10%H2SO4和3.5%NaCl溶液中的耐蚀性能进行了对比试验研究.结果表明:复合渗镀 PVD法沉积的TiN薄膜呈较为均匀、致密、细小的组织,Ti和N原子由表层呈梯度向内分布.与PVD法沉积的TiN层不同,是属于冶金扩散结合层,渗镀层厚度可达10 μm以上.在10%H2SO4和3.5%NaCl溶液中,渗镀层的腐蚀速度分别为0.156g/(m2·h)和0.025g/(m2·h),显示出了优异的耐蚀性.     

等离子辉光合成TiN渗镀层耐腐蚀性能的研究

介绍了一种同时利用等离子尖端放电、空心阴极效应和反应气相沉积技术,在碳钢表面形成具有扩散层和沉积层的TiN渗镀层新工艺技术.将该TiN渗镀试样与1Cr18Ni9Ti不锈钢和Q235钢在1 mol/LH2SO4溶液和3.5%NaCl溶液中,分别进行电化学腐蚀对比试验.结果表明：TiN渗镀层在酸性溶液中的耐蚀性能比1Cr18Ni9Ti不锈钢和Q235钢分别提高了1.4和4.2倍.在盐水中的耐蚀性能比Q235钢提高了182.6倍,但比1Cr18Ni9Ti不锈钢耐蚀性能稍差.渗镀TiN层耐酸性溶液腐蚀性能优于耐盐水腐蚀性能.     

38CrMoAl钢表面电刷镀—氮碳共渗复合处理工艺研究

利用光学显微镜、扫描电子显微镜和Ｘ射线衍射,分析了经电刷镀Ｎｉ－Ｗ合金与氮碳共渗复合工艺处理的３８ＣｒＭｏＡｌ钢表面层的性能、显微组织和相组成,并进行了磨损试验,探讨了电刷镀层厚度、氮碳共渗时间对表面硬化层性能和显微组织的影响。结果表明,氮碳共渗后使３８ＣｒＭｏＡｌ钢表面的电刷镀层与基体的结合由原来的机械结合转变为冶金结合。复合工艺处理后的表面层组织为Ｎｉ基体上分布着少量的ＷＣ和ＷＮ质点,其表面耐磨性较只进行电刷镀处理或氮碳共渗处理的提高了５倍以上。最佳的电刷镀层厚度为２０ｕｍ,最佳的氮碳共渗保温时间为８０ｍｉｎ。     

基于加弧辉光复合渗镀技术的Al2O3陶瓷表面合金化

基于加弧辉光复合渗镀技术，采用自行研制的复合靶对Al2O3陶瓷表面进行Cu、Tu复合渗镀，实现了Al2O3陶瓷表面合金化：采用光学显微镜、SEM、EDS、XRD、声发射划痕等测试手段对渗镀层进行分析。研究了复合渗镀机理、渗镀层成分和元素分布、渗镀层相结构以及渗镀层与基体的接合机理。在100N的最大载荷下，渗镀层与陶瓷基体未发生剥离和崩落现象。这种方法为各种陶瓷材料表面合金化及其与金属材料的微连接提供了新途径。     

电刷镀在表面工程中应用的研究进展

综述了电刷镀技术在材料表面防腐、耐磨及维修领域的应用。 介绍了电刷镀耐蚀、耐磨镀层的新工艺及其性能,包括纳米晶合金电刷镀层、纳米复合电刷镀层、双纳米复合电刷镀层以及电刷镀复合转化膜层的研究现状。 最后指出了今后电刷镀技术研究应用的方向。     

PCVD复合渗镀刀具表面强化

研究了PCVD复合渗镀高速钢刀具表面强化方法。复合渗镀层由（Ti，Si）N镀层和离子渗氮层组成。研究了Ti／Si对（Ti，Si）N系镀层的硬度、组织形貌、抗氧化性能和结合力的影响。切削试验结果表明，复合渗镀处理可显著改善高钢刀具切削性能，提高刀具寿命。     

电刷镀多层复合镀层的应用研究

用电刷镀研制具有层状结构的Ni-Cr2O3复合电刷镀层，采用碱铜层作为中间过渡层；研究了多层复合镀层的组织，显微硬度以及耐磨性等性能，对电刷镀多层复合镀层工艺进行了实际应用研究，结果表明，多层Ni-Cr2O3复合电刷镀层与Ni镀层相比具有较高的显微硬度，细小的结晶晶粒和较耐磨性，层状的复合镀层结构会导致磨损机理的变化，该工艺可用于大型机械设备现场不解体修复。     

双层辉光等离子制备TiN渗镀层的耐蚀性能

利用双层辉光等离子表面合金化技术,在Q235钢表面直接合成TiN渗镀层,该渗镀层由TiN颗粒均匀分布的扩散层及表面TiN沉积层组成。将TiN渗镀层与Q235钢基体和1Cr18Ni9Ti不锈钢在4%的NaOH溶液、l mol/L H2SO4溶液和3.5%NaCl溶液中分别进行电化学腐蚀对比试验。结果表明:在4%的NaOH溶液中,TiN渗镀层的耐蚀性能比Q235钢提高了26.8倍,与1Cr18Ni9Ti不锈钢相当;在l mol/L H2 S04溶液中,TiN渗镀层耐腐蚀性能比Q235钢提高了10.5倍,比1Crl8Ni9Ti不锈钢提高了1.65倍;在3.5%的NaCl溶液中,TiN渗镀层耐腐蚀性能比Q235钢提高了10.3倍,但比1Crl8Ni9Ti不锈钢稍差。TiN渗镀层耐酸碱性溶液腐蚀性能要比耐盐溶液腐蚀性能强。     

Erosion-corrosion behavior of nano-particle-reinforced Ni matrix composite alloying layer by duplex surface treatment in aqueous slurry environment

The present study concerns a duplex surface treatment of AISI 316L stainless steel to enhance the erosion-corrosion resistance. The duplex surface treatment consisted of Ni/nano-SiC and Ni/nano-SiO₂ predeposited by brush plating and a subsequent surface alloying with Ni-Cr-Mo-Cu by double glow process of the substrate. Results showed that under alloying temperature (1000 °C) condition, the amorphous nano-SiO₂ particles still kept the amorphous structure, whereas the nano-SiC particles had been completely decomposed and Ni, Cr reacted with SiC to form Cr_6.5Ni_2.5Si and Cr₂₃C₆. The electrochemical corrosion behaviors of composite alloying layers compared with the single alloying layer and 316L stainless steel were measured under a range of hydrodynamic conditions by recording the current response, open circuit potential, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Results showed that the increase of the impact velocity had significant influence on the current density of composite alloying layer with brush plating Ni/nano-SiC particles interlayer obtained under flowing condition at a potential of 200 mV, whereas there were only small fluctuations occurred at current response of composite alloying layer with brush plating Ni/nano-SiO₂ particles interlayer. The results of potentiodynamic polarization indicated that, with increasing impact velocity under slurry flow conditions, the corrosion potentials of test materials decreased and the corrosion current densities of test materials increased. The corrosion resistance of composite alloying layer with brush plating Ni/nano-SiO₂ particles interlayer was prominently superior to that of single alloying layer under slurry flow conditions; the corrosion resistance of composite alloying layer with brush plating Ni/nano-SiC particles interlayer was evidently lower than that of single alloying layer, but higher than that of 316L stainless steel under slurry flow conditions. The results of EIS indicated that, with respect to the R_tot obtained in sand-free flow, the impacts of sand particles dramatically decreased the R_tot values of composite alloying layer with brush plating Ni/nano-SiC particles interlayer, single alloying layer and 316L stainless steel, whereas the impact action slightly decreased that of composite alloying layer with brush plating Ni/nano-SiO₂ particles interlayer. The weight loss rate studies suggested that the highly dispersive nano-SiO₂ particles were helpful to improve the erosion-corrosion resistance of composite alloying layer, whereas the carbides and silicide phase were deleterious to that of composite alloying layer due to the fact that preferential removal of matrix around the precipitated phase takes place by the chemical attack of aggressive medium.     

Erosion–corrosion characteristic of nano‐particulates reinforced Ni–Cr–Mo–Cu surface alloying layer in acidic flow and acidic slurry flow

In order to improve the corrosion and erosion–corrosion resistance of 316L stainless steel in engineering application, two kinds of composite alloying layers were prepared by a duplex treatment, consisting of Ni/nano‐SiC and Ni/nano‐SiO₂ predeposited by brush plating, respectively, and a subsequent surface alloying with Ni–Cr–Mo–Cu by double glow process. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were performed on the two kinds of composite alloying layer using 10 wt% HCl solution to assess the corrosion behavior. Erosion–corrosion tests were carried out by erosion–corrosion test rig in acidic flow and acidic slurry flow for test time of 20 h at four different rotational speeds. Results of electrochemical tests indicated that the corrosion resistance of composite alloying layer with brush plating Ni/nano‐SiO₂ particles interlayer approximated to that of single Ni‐based alloying layer, whereas the corrosion resistance of the composite alloying layer with brush plating Ni/nano‐SiC particles interlayer was apparently inferior to that of Ni‐based alloying layer in 10 wt% HCl solution at static state. Under the conditions of acidic flow and acidic slurry flow, the mass losses of tested samples increased with increase in the time of erosion–corrosion tests and the rotational speeds of samples. The mass losses of composite alloying layer with brush plating Ni/nano‐SiO₂ particles interlayer were lower than that of single Ni‐based alloying layer at all rotational speeds, except at 1.88 m/s in acidic flow. The mass losses of composite alloying layer with brush plating Ni/nano‐SiC particles interlayer were higher than that of single Ni‐based alloying layer at all rotational speeds, but were obviously lower than that of AISI 316L stainless steel. The influences of second phase on the corrosion and erosion–corrosion of the two kinds of composite alloying layer were discussed in this paper.     

利用双层辉光等离子技术进行镍基耐蚀合金表面合金化的研究

研究了在 2 0钢和不锈钢基材上 ,利用双层辉光离子渗金属技术进行Ni Cr Mo Cu多元共渗表面合金化 ,采用电化学方法对两种基材表面形成的渗层在 5 %HCl中的腐蚀性能进行了测定。结果表明 :在两种基材上都能得到类似于源极HastelloyC - 2 0 0 0合金的表面合金渗层 ,在不锈钢表面上形成的渗层的耐蚀性能接近HastelloyC - 2 0 0 0合金并且优于Alloy 5 9合金 ,在 2 0钢表面上形成的渗层耐蚀性能优于不锈钢Cr18Ni9     

Effect of nano-Al2O3 on erosion–corrosion behaviour of composite alloying layer under two phase flow conditions

Abstract

The present study was focused on understanding the effect of the added nano-Al₂O₃ on erosion–corrosion behaviour of composite alloying layer. The nano-Al₂O₃ reinforced composite alloying layer was prepared by duplex surface treatment, which consisted of Ni/nano-Al₂O₃ predeposited by brush plating and a subsequent surface alloying with Ni–Cr–Mo–Cu by double glow process on the surface of AISI 316L stainless steel. Current response with applied potential, potentiodynamic polarisation curve, electrochemical impedance spectroscopy and weight loss techniques were applied to evaluate the erosion–corrosion behaviour of composite alloying layer compared with the single alloying layer and 316L stainless steel under hydrodynamic conditions. Results of electrochemical measurements showed that the erosion–corrosion resistance of composite alloying layer was lower than that of single alloying layer when the rotating velocity of tested samples was below 2·51 m s^?1, whereas the erosion–corrosion resistance of composite alloying layer was higher than that of single alloying layer when the rotating velocity of tested samples above 2·51 m s^?1. The weight loss rate studies and surface analysis suggested that the dispersive undissolved nano-Al₂O₃ particles and γ′ prime (Ni₃Al) phase were helpful to improve the erosion–corrosion resistance of composite alloying layer at high rotational speed, though the γ′ prime phase was deleterious to corrosion resistance of composite alloying layer.     

Study on composite surface treatment of 38CrMoAl steel

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电刷镀Ni-W过渡层与离子镀TiN复合涂层的结合力和磨损特性

研究了3Cr2W8V基体电刷镀Ni-W过渡层和离子镀TiN复合涂层的结合力及强化机理.利用XRD、SEM和TEM分析了涂层结构,用划痕法测定了涂层结合力,并测定和分析了涂层的磨损特性.结果表明由于TiN沉积过程中的温度效应,混合晶态的电刷镀Ni-W层发生晶化和析出强化,并形成界面扩散层和双层复合,从而使TiN复合涂层的结合力和硬度明显提高;Ni-W过渡层对TiN涂层起有力的支撑作用.Ni-W与TiN复合涂层的耐磨性优于TiN单层.     

镁合金表面Ni+C涂层的耐腐蚀与耐磨性能研究

目的提高镁合金表面的耐腐蚀和耐磨损性能。方法采用非平衡磁控溅射离子镀技术与化学镀技术相结合,在GW83镁合金表面制备Ni+C复合膜层。通过扫描电子显微镜和拉曼光谱分析了薄膜的形貌、成分和结构。利用电化学和浸泡后ICP-AES测试,评价了该复合碳膜涂层的耐腐蚀性能。同时采用摩擦磨损试验获得Ni+C复合膜层的磨损寿命。结果 Ni+C复合膜层致密均匀,表面孔隙率极低,表面碳层为典型的类石墨膜并且含有大量的无序结构。相对于GW83镁合金来说,Ni+C复合膜层的存在导致在3.5%Na Cl溶液中的腐蚀电位正移了301 m V,腐蚀电流密度从186μA/cm2降低至11μA/cm2。浸渍后ICP-AES试验显示,Ni+C涂覆的镁合金GW83的金属离子释放量更低。摩擦磨损试验表明,Ni+C涂层的磨损寿命为7000 s,与镁合金基体相比,Ni+C复合涂层极大地提高了其磨损寿命。结论在该Ni+C复合膜层中,表面碳层较致密,与Ni层结合良好,显著提高了基体的耐腐蚀性能。此外由于存在较厚的Ni中间层,对膜层起到了较大的支撑作用,Ni+C复合膜层从而延长了基体镁合金的磨损寿命。     

低碳钢表面Cr—Ni激光合金化的耐蚀性

研究了低碳钢表面Ｃｒ－Ｎｉ激光合金化工艺,并对处理后的合金层组织与性能进行了测试分析。结果表明,Ｃｒ－Ｎｉ激光合金化可获得一特殊的显微组织形态,它不但具有高的硬度,而且有着极强的耐蚀性,由于激光的作用,使低碳钢的基体也产生了一定的强化效果。     

Preparation of Ni-Cu-Mo-Cr film deposited on AZ31magnesium alloy by double glow sputtering with Cu interlayer

For improving the corrosion resistance of AZ31magnesium alloy, a double glow sputtering deposited Ni-Cu-Mo-Cr film with brush plating Cu interlayer is applied to deposit a metal amorphous/nanocrystal film on AZ31magnesium alloy. Using a brush plated Cu interlayer, the content of noble elements, such as Ni, Cr, and Mo, is higher than that of a Ni-based film without Cu interlayer. The microstructure of the Ni-Cu-Mo-Cr alloy film with the brush plated Cu interlayer confirms that the film is classified into two regions, i.e., an amorphous layer on the outmost surface and an underlying nanocrystalline layer with a grain size of less than 5 nm. The Ni-based alloy amorphous film formed on AZ31magnesium alloy was investigated using an electrochemical polarization measurement. Compared with the AZ31 magnesium alloy, the sputter-deposited Ni-based alloy film and the sputter-depostion Ni-based alloy film with a brush plated Cu interlayer formed on AZ31 magnesium alloy exhibit obvious passivation phenomena.