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1.
采用激光加工在中碳钢基体表面制备了成形良好、稀释率低、组织细密的MnCu合金涂层.对合金涂层进行了电解腐蚀处理,涂层中的Mn原子被电解液溶解,Cu原子经扩散、团聚、生长并形成了纳米多孔Cu涂层.涂层的孔洞尺寸为30—50nm,具有高比表面积.Mn-Cu合金涂层的初始成分对纳米多孔Cu涂层的微观形貌有较大的影响.  相似文献   

2.
绿色海洋防污材料的表面构筑研究进展   总被引:1,自引:0,他引:1  
海洋生物污损已成为影响船只与装备在海洋环境中服役性能的全球性问题。因此,发展高效、广谱、环境友好的防污材料势在必行。借鉴海洋生物表皮具有的天然防污特性,人们通过对材料的表界面组分、形貌设计,获得了一系列环境友好型防污材料。文中系统归纳和评述了低表面能材料、表面亲水性材料、表面织构化材料和表面植绒材料等依靠表面物化性能调控来获得具有优异防污表现的绿色防污材料的研究进展,最后指出当前绿色防污材料存在的问题及未来的发展方向。  相似文献   

3.
目的研究Mg_3Sb_2含量对Al-Mg_3Sb_2复相涂层的组织、硬度和摩擦学性能的影响,对比分析AZ31B镁合金基体、纯Al涂层和添加不同含量的Mg_3Sb_2之后涂层性能的差异。方法通过火焰喷涂技术在AZ31B镁合金表面制备了Al-Mg_3Sb_2复相涂层。利用扫描电镜(SEM)观察了涂层的截面形貌,利用X射线衍射仪(XRD)分析了涂层的物相组成。通过显微硬度计测试了AZ31B和涂层的硬度,通过摩擦磨损试验仪测试了AZ31B和涂层的摩擦学性能,并通过超景深三维显微镜测试了试样的磨痕宽度、深度及磨损体积。结果经火焰喷涂后可得到组织致密的复相涂层,涂层中的物相主要为Mg_3Sb_2和Al。涂层的平均硬度随Mg_3Sb_2含量的增加而增加,最高可达334.2HV0.025,是AZ31B的4.14倍。摩擦磨损试验中,涂层的摩擦系数随着Mg_3Sb_2含量的增加而减小,但都大于AZ31B的摩擦系数;涂层的磨损率随着Mg_3Sb_2含量的增加而减小,60%Mg_3Sb_2和80%Mg_3Sb_2涂层的磨损率小于AZ31B的磨损率,其他涂层的磨损率大于AZ31B的磨损率,80%Mg_3Sb_2涂层的耐磨性最好,比AZ31B下降了63.26%。随着Mg_3Sb_2含量的增加,Al-Mg_3Sb_2复相涂层的磨痕表面犁沟逐渐变浅并消失。结论 Mg_3Sb_2的加入可以提高涂层的硬度,随着其含量的增加,涂层的耐磨性逐渐提高。  相似文献   

4.
钼对钴基合金激光熔覆层组织与耐磨性的影响   总被引:2,自引:2,他引:0       下载免费PDF全文
利用激光熔覆技术在低碳钢基体表面制备了钴基合金涂层.利用金相显微镜(OP)、扫描电镜(SEM)及x射线衍射仪(XRD)等研究了不同Mo元素含量的钴基合金涂层的组织结构;通过采用显微硬度试验、滑动磨损试验等方法进行性能测试.结果表明,含5.4%Mo的合金熔覆层主要组成相为γ-Co,Cr_(23)C_6,而含28%Mo的合金涂层主要相组成为γ-Co,Cr_(23)C_6,Co_3Mo_2Si_2和NiCor等相;含5.4%Mo涂层的组织主要为柱状生长树枝晶;含28%Mo单道涂层的结合区为紊乱的粗大树枝晶,中部为向上生长的细小的树枝晶,表层为细小的等轴晶,多道搭接涂层组织为细小的等轴晶;含28%Mo涂层的显微硬度可达800 HV以上,比含5.4%Mo涂层的硬度提高了一倍;耐磨性也有不同程度的提高.
Abstract:
Co-based alloy coatings with different Mo content (5.4% and 28 % ) on the surface of low carbon steel were prepared by laser cladding. The microstructure and phases composition of the coatings were investigated by means of optical microscope (OP), scanning electron microscope (SEM) and X-ray diffraction instrument (XRD). Microhardness and sliding wear resistance of the coatings were also tested. The results indicated that the main phases in Co-based alloy coatings with 5.4%Mo were γ-Co and Cr_(23) C_6. Another two phases of Co_3 Mo_2 Si and NiCoCr were identified in Co-based alloy coatings with 28% Mo. Directional dendrite was observed in Co-based alloy coatings with 5.4% Mo. Unidirectional dendrite at the interface, followed by fine dendrite at the central zone and equiaxed grain near top surface were found in Co-based alloy single coatings with 28% Mo, and almost all fine equiaxed grains appear in the multi-track coatings. The microhardness of Co-bascd alloy coatings with 28% Mo reaches up to 800 HV, which was 2 times of that of Co-based alloy coatings with 5.4% Mo. The sliding wear resistance was also improved.  相似文献   

5.
表面活性剂对电沉积Ni-纳米Si3N4复合镀层的影响   总被引:4,自引:1,他引:3  
采用电沉积法,制备Ni-纳米Si3N4复合镀层.研究了2种表面活性剂对复合镀层的粒子含量及耐磨性的影响.利用扫描电镜(SEM)观察复合镀层的表面形貌.结果表明:表面活性剂对电沉积Ni-纳米Si3N4复合镀层有较大的影响;采用非离子表面活性剂与阳离子表面活性剂的复配组合制备的复合镀层优于单独使用一种表面活性剂制备的镀层.  相似文献   

6.
为了提高 MgF2 膜层的耐腐蚀性能,利用微弧氧化工艺,通过在 NH4F-EG 电解液中添加纳米 SiC 颗粒,在 AZ31 镁合金表面制备含 SiC 的 MgF2 -SiC 膜层,并探究纳米 SiC 颗粒的浓度对 MgF2 膜层组成、结构和耐腐蚀性能的影响。 采用 SEM、EDS、XRD、XPS 等测试方法对含 SiC 的 MgF2 膜层的微观组织、元素含量和物相组成进行分析,利用电化学工作站对膜层的耐腐蚀性能进行测试。 结果表明:电解液中的纳米 SiC 颗粒成功进入 MgF2 膜层中。 随着电解液中纳米 SiC 浓度的增加,膜层中的 Si、C 元素含量增加,Mg、F 元素含量减少,膜层变得致密平整,孔隙率减少,膜层缺陷得到有效改善,膜层厚度减小;MgF2 膜层的耐腐蚀性能先增大后减小,当电解液中纳米 SiC 的浓度为 5 g / L 时,膜层的耐腐蚀性能最优。 因此,在 NH4F-EG 电解液中添加纳米 SiC 颗粒,可以在 AZ31 镁合金表面制备出含 SiC 的 MgF2 -SiC 膜层, 且耐腐蚀性能优于不含 SiC 的 MgF2 膜层。  相似文献   

7.
周生健  白玉  迟柏祥  尹雪  马文 《表面技术》2019,48(7):340-346
目的 采用悬浮液等离子喷涂技术(SPS)在纯钛表面制备氟代羟基磷灰石/硅酸钙(FHA/CS)生物复合涂层。方法 利用X射线衍射仪(XRD)、傅里叶红外光谱仪(FT-IR)、扫描电子显微镜(SEM)及能谱仪(EDS)对复合涂层的物相组成、组织结构和显微形貌进行分析。通过动电位极化测试和体外生物活性测试,分析复合涂层在模拟体液(SBF)中的腐蚀行为和类骨磷灰石形成能力。通过电感耦合等离子体光谱仪(ICP)分析涂层中Ca2+的释放行为,评估复合涂层的化学稳定性。采用划痕法表征涂层的结合强度。结果 SPS制备的复合涂层具有粗糙的表面和层片堆叠结构。涂层中FHA和CS两相分布均匀,结晶性良好。复合涂层临界载荷达到111.43 N,比单一FHA涂层提高62.5%。与纯钛相比,涂层样品具有较高的腐蚀电位(Ecorr)和较低的腐蚀电流密度(Jcorr)。在SBF溶液中浸泡3天,涂层样品表面被类骨磷灰石完全覆盖。ICP结果表明,复合涂层中Ca2+释放速率低于单一CS涂层。结论 通过SPS在纯钛表面制备的FHA/CS复合涂层具有良好的生物活性、耐腐蚀性能和与基体的结合强度,复合涂层中FHA组分的存在有利于提高涂层的化学稳定性。  相似文献   

8.
研究了等离子喷涂不同结构YSZ涂层在CMAS渗入作用下的形貌演变规律。对带有模拟CMAS沉积物的YSZ涂层进行高温热处理试验,并在低CMAS输送量条件下对YSZ涂层进行冲刷试验,试验后涂层均出现了严重的层间剥离失效。通过试验前后涂层的截面形貌及Raman光谱分析,结果表明:涂层的显微形貌变化主要表现在高温下熔融态CMAS沿涂层表面微裂纹和孔隙渗入内部,引起YSZ陶瓷层孔隙收缩、表层致密化,同时在涂层表面粘附的CMAS耦合作用下,YSZ涂层表层中产生大量横向微裂纹和明显分层;另外,YSZ涂层表层在CMAS中溶解并导致YSZ加速相变失稳也是影响涂层形貌变化和过快失效的因素之一。CMAS沉积层厚度增加时,同等条件下CMAS对涂层失效的影响会加剧。  相似文献   

9.
使用闭合场非平衡磁控溅射离子镀技术,通过改变偏压在镁合金表面制备了CrAlTiN镀层,对镀层厚度、硬度、结合力和耐磨性进行了检测,使用SEM和XRD分析了镀层的形貌和相组成,结果表明:通过改变偏压可以在镁合金表面沉积一层具有一定耐磨性能的CrAlTiN镀层;偏压对镁基CrAlTiN镀层的结合力和耐磨性影响很大,在偏压为35V时具有最好的结合力和耐磨性能,随着偏压的增大,镀层硬度提高,致密性增强,厚度降低;镁基CrAlTiN镀层为柱状晶组织,具有面心立方结构,点阵类型与面心立方CrN相同.  相似文献   

10.
钛合金表面离子束增强沉积的Cr和CrMo合金膜层及其性能   总被引:5,自引:1,他引:5  
利用多功能离子束增强沉积(IBED)设备,在Ti6Al4V钛合金表面制备Cr和CrMo合金膜层,以提高钛合金表面的耐磨性能。利用X射线衍射仪、扫描电子显微镜、辉光放电光谱仪和显微硬度计分析和测试了IBED膜层的结构、形态、成分分布、硬度和膜基结合强度的大小。利用球一盘磨损试验机和电化学综合测试仪研究了IBED膜层的摩擦学性能和电化学腐蚀特性。结果表明,利用IBED方法可以在难镀材料钛合金表面制备膜基结合强度高、结晶致密和晶粒尺寸达纳米级的高硬度Cr膜和CrMo合金膜层,显著提高了钛合金表面的抗磨性能,且膜层本身有很好的耐Cl^-介质环境电化学腐蚀性能,与钛合金基体之间有很好的接触腐蚀相容性。  相似文献   

11.
Cr-Cu-N coatings with copper content from 0 at%to 6.8 at%were deposited on silicon and M2 steel by ion beam assisted magnetron sputtering.The microstructure and composition of the coatings were characterized using SEM,GDOES,XRD and XPS.The mechanical properties of the coatings were tested on a standard hardness tester.The tribological behavior of the coatings in dry wear condition was studied by means of ball-on-disc wear test.The experimental results show that addition of copper can restrict the columnar crystal growing to a certain degree.XRD and XPS analysis indicate that coatings are mainly composed of Cr and CrN phase.Cu is mainly existed in a free state in the coatings.Copper adding has no obvious effects on the hardness of the coatings.However,the coatings fracture toughness can be improved by doped copper.The coefficient of friction of the coatings against bearing steel is in the range of 0.25-0.6 changing with the copper content.The coating with 2.6 at%copper shows the lowest coefficient of friction about 0.25 and wear rate which is about one tenth of that of the coating with 6.8 at%copper.The higher coefficient of friction and wear rate of the coating with 6.8at%copper may be attributed to its lower bonding strength.  相似文献   

12.
Active element modified aluminide diffusion coatings on IN738 substrates were produced by a new route using continuously cast, aluminum alloy wires consisting of Al‐Y, Al‐Ce, Al‐La and Al‐Si‐Y. The cast wires were used as evaporation sources for ion‐vapour deposition followed by diffusion heat treatments to form nickel aluminide coatings. In order to examine the oxidation resistance of these coatings at elevated temperatures, thermal cyclic oxidation experiments were carried out in air at 1050°C. While all coatings were found to provide significant protection, the Al‐La modified coatings provided the greatest resistance to cyclic oxidation. On the other hand, with coatings based on Al‐Si‐Y alloys, while silicon has a strong ability to reduce the outward diffusion of aluminum, the adverse effect of silicon on mechanical properties of the coating, together with the formation of volatile silicon monoxide, led to catastrophic localized oxidation of the protective coatings.  相似文献   

13.
主要综述了海洋环境抗磨蚀防护涂层及技术的发展现状,对比了喷涂、高能束表面改性、物理气相沉积(Physical vapor deposition,PVD)三种常用技术的优劣势,并归纳了不同涂层在海水磨蚀条件下的磨损率和腐蚀电流密度,发现PVD制备的氮/碳基涂层呈现出更优的耐摩擦防腐蚀性能.进一步对海洋环境氮基与碳基抗磨蚀防护涂层的研究成果进行了重点阐述,探讨了组分、过渡层以及多层结构设计等对涂层微结构、力学及磨蚀性能的影响,剖析了涂层在海水磨蚀环境中的失效分析方法和损伤机理.最后,对海洋抗磨蚀防护涂层的未来发展方向进行了思考与展望.  相似文献   

14.
Bonding strength of diamond-like carbon (DLC) films on zirconia coatings prepared using a novel gas tunnel plasma spraying method has been studied and discussed. The emphasis is on the getting better characteristics of such doubly structured coatings (DSC) as comparing compared with properties of both components involved in the coatings. For the study of various failure mechanisms zirconia coatings of different thicknesses on aluminum substrates were prepared. The as-sprayed coatings were firstly polished and then subjected to deposition of DLC films. Adhesion of the DSC has been evaluated using a scratch test method. It has been found that the thicker coatings have higher hardness and lower porosity. The adhesion failures of DLC films on zirconia coatings (DSC) are caused by two different main mechanisms: (i) DLC films separation from the zirconia coatings, and (ii) DLC films breaking under stress load due to the brittleness of the material. In addition the adhesion failures are due to flaking of DLC films on the thinner zirconia coatings caused by a distortion of the aluminum alloy substrate coatings; and, chipping of DLC films themselves on the thicker zirconia coatings.  相似文献   

15.
利用电弧喷涂技术、渗铝和扩散处理工艺,在铸铁表面制作了具有微冶金结合的18-8不锈钢耐热耐蚀涂层.采用光学显微镜,SEM及X射线衍射等方法,对经过不同渗铝和扩散处理工艺得到的涂层的组织形貌,相结构及成分进行了分析研究.并采用热疲劳试验对渗铝和扩散处理后涂层的结合强度进行评价.结果表明,通过渗铝和扩散处理,涂层与基体之间产生了微冶金结合,涂层的结合强度得到了显著提高.并且渗铝时间过长不利于提高涂层结合强度,应合理控制渗铝时间.  相似文献   

16.
Ti靶电流对CrTiAlN镀层组织结构及硬度的影响   总被引:1,自引:0,他引:1  
利用磁控溅射技术在高速钢和单晶硅基体上沉积CrTiAlN梯度镀层,研究Ti靶电流对CrTiAlN镀层组织、相结构及硬度的影响.利用EDS、XRD和SEM分析镀层的成分、相结构及形貌,采用显微硬度计测量镀层的硬度.结果表明:随着Ti靶电流的增大,镀层中的Ti原子逐渐置换CrN中的Cr原子形成Cr-Ti-N体系,同时出现少量的TiN相;镀层生长的择优取向由(111)晶面逐渐转变为(200)晶面;镀层柱状晶的结构更为致密,其表面形貌由三棱锥结构逐步变为胞状结构;随Ti靶电流的增大,镀层硬度逐渐由1267HV升至1876HV.  相似文献   

17.
Magnesium alloys are highly reactive and require protection for their successful applications. In this work, coatings of 10 μm and 25 μm nominal thicknesses were prepared by Plasma Electrolytic Oxidation on AM50B and AM60B alloys. The effect of subsequent post-PEO treatments such as alkaline phosphate, alkaline silicate and sol-gel sealing was studied on coatings with 10 μm thickness. The microstructure and composition of the PEO coatings and post-treated coatings were analysed by Scanning Electron Microscope and Energy Dispersive X-ray Spectroscopy. Phase analysis of the coatings was carried out using X-ray Diffraction method. Potentiodynamic polarization method was used to evaluate the corrosion behaviour of these coatings in 3.5% NaCl solution. Electrochemical corrosion results indicated that the sealed PEO coatings of 10 μm thickness showed better corrosion resistance than the unsealed PEO coatings of 25 μm thickness. The structural surface defects of the PEO coatings were sealed by post-treatments resulting in decreases in surface roughness and open pores. Sol-gel post-treatment provided the most effective sealing to the PEO coatings.  相似文献   

18.
采用超音速等离子喷涂技术将新型多元铝青铜合金粉体喷涂在45号钢基体表面。运用XRD、SEM、EDS、EPMA等手段分析了涂层的组织特点及元素分布情况。结果表明,超音速等离子喷涂层主要由Cu9Al4、AlFe3、AlFe等相组成;涂层元素分布均匀;超音速等离子喷涂层硬度高于传统等离子喷焊层;涂层的结合强度为59.3MPa。可见,经过工艺参数的优化,超音速等离子喷涂可以制备出类似于多元铝青铜合金的易氧化涂层。  相似文献   

19.
将磷化后的热镀锌钢板用钼酸盐后处理,以提高磷化膜的耐蚀性。用SEM、EDS、电化学极化测量和盐雾试验研究了钼酸盐后处理对磷化膜组成和耐蚀性的影响。结果表明,经钼酸盐处理后,磷化膜上磷酸锌晶体间的孔隙被钼酸盐膜填补,从而在锌层表面形成了由磷化膜和钼酸盐膜构成的连续完整致密的复合膜;复合膜的极化电阻Rp显著增大,腐蚀电流密度显著减小,耐蚀性大大增强。磷化300s、后处理50s时复合膜的耐蚀性最优,Rp比单磷化膜的增加了一个数量级。  相似文献   

20.
目的通过研究电沉积方式对Ni-SiC纳米复合镀层性能的影响,进而改善Ni-SiC纳米复合镀层的性能。方法采用直流电沉积和脉冲电沉积分别制备Ni和Ni-SiC纳米复合镀层,使用扫描电镜和能谱仪研究镀层的表面形貌和成分,通过测量施镀前后镀件质量差计算沉积速率,采用硬度计测量了镀层的硬度,利用极化曲线和电化学阻抗方法研究镀层在3.5%NaCl水溶液中的耐腐蚀性能,分析了直流电沉积方式和脉冲电沉积方式对镀层各项性能的影响。结果脉冲电沉积方式制备的Ni-SiC纳米复合镀层的表面形貌更加致密、均匀、光滑,镀层硬度为616.3HV,自腐蚀电流为9.56×10~(-6) A,比直流电沉积制备的Ni-SiC纳米复合镀层的硬度和耐蚀性能均有所提高。结论电沉积方式对复合镀层的性能有很大影响,脉冲电沉积方式制备的Ni-SiC纳米复合镀层具有更好的性能。  相似文献   

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