Ni-P-SiO2(纳米)化学复合镀研究

通过Ni-P化学镀及Ni-P-SiO2(微米)、Ni-P-SiO2(纳米)化学复合镀探讨纳米SiO2颗粒对镀速及镀层性能的影响。结果表明：添加适量的SiO2纳米粒子于镀液中，使镀速上升，所得镀层硬度、耐磨性等性能相对于Ni-P镀层及微米颗粒复合镀层都有显著地提高。     

The Influence of High Temperature Exposure on the Wear Performance of a Ni Based Alloy PTA Coating

Degradation phenomena like wear and corrosion, may have their effects accelerated as components operate at high temperature. The aim of this work is to make an indirect evaluation of the influence of high temperature exposure on wear behavior of Ni coatings. A Ni-Cr-Mo-W alloy, was deposited with Plasma Transferred Arc (PTA) process. An indirect approach based on the Ahrrenius relationship was used to evaluated long time exposures at high temperatures. To simulate longer exposures at lower temperatures, coatings were exposed to higher temperatures for the same time interval. So coatings were soaked in an air furnace at 650℃, 1000℃ and 1200℃. Metal/metal wear behavior was evaluated by pin-on-disc tests. Pins were removed from the coatings by eletrodischarge machining and rubbed against a VC31 quenched and tempered tool steel. Two sets of wear tests were run at 2m/s, for different loads (0.5, 1.0, 2.0 and 3.0Kg) and for different sliding distances (120, 720, 1080, 1440 and 1800m).Coatings characterization was done by scanning electronic microscopy and Vickers microhardness. Results showed as temperature is increased, coatings wear performance is altered,and this is associated with microstructural changes.     

Microstructural features and properties of plasma sprayed YPSZ/NiCrAlY thermal barrier coating (TBC)

0　IntroductionThermalbarriercoatings(TBCs)arewidelyusedontheturbinebladesforaircraftpropulsionorpowergenerationtoreducethemetallicsubstratetemperature,whichleadstoincreasingengineefficiencyandloweringpollutantemissionsresultingfromallowableincreaseofoperationtemperature[1,2].Today,TBCsareattractingmoreattentionandhavewiderpotentialapplicationstoprotecthightemperaturecomponents.However,thermalbarriercoatingshaveatendencytocrackandspallinserviceduetothermalshockandthermalcyclingbetweenambient…     

铸钢件表面铸渗钨铬复合层的研究

采用传统的铸渗技术在铸钢件表面形成钨铬表面复合层，并考察了其组织、硬度和复合层的冲击磨损性能。结果表明，在实验条件下，当冲击功小于2J、渗剂中WC、铬铁含量分别为(质量分数)20％、40％时，复合层的冲击磨损性能最佳，是ZG230—450的12．5倍。     

Mg-8Zn-4Al的化学镀Ni-P合金

本文在大量实验的基础上，得到了适合在Mg-8Zn-4Al镁合金上施镀的工艺及配方，通过性能检测，得到的镀层结构致密、稳定，具有较高的硬度和良好的耐蚀性。     

腐蚀磨损中几种测量纯机械磨损分量方法的比较

研究了腐蚀磨损交互作用量中纯机械磨损分量的测量方法,采用暂态腐蚀磨损试验机,并将试样分别置于单纯的蒸馏水中,或置于蒸馏水后同时加以阴极保护或添加缓蚀剂的三种条件下进行测量,并用空气中的磨损量作对比。3种方法得到的纯机械磨损量和摩擦系数接近,可作为腐蚀磨损交互作用中各分量的计算,但在蒸馏水中因纯铁和1045钢有腐蚀仍不宜使用。     

Penetration treatment of plasma-sprayed ZrO2 coating by liquid Mn alloys

The penetration phenomena of liquid manganese (Mn) alloy into porous ZrO₂ (8 vvt % Y₂O₃) coating plasma sprayed on SS400 steel substrate was studied by heating in a vacuum atmosphere. The improvement in mechanical properties of the coating by heat treatment with liquid Mn alloys was examined. Liquid Mn alloys, such as Mn-Cu, Mn-Sn, and Mn-In, rapidly penetrated the coating and formed a chemical bond between the coating and the substrate. The densification of the ZrO₂ coating occurred when ZrO₂ particles were sintered with liquid Mn alloys that penetrated the porous coating. The dense coating was free of porosity, and its hardness increased after heat treatment with Mn alloys, compared with assprayed ZrO₂ coating. Moreover, the fracture toughness of the coating reached the same levels as those of sintered yttria-stabilized PSZ.     

Wear mechanism of electrodeposited amorphous Ni-Fe-P alloys

1　INTRODUCTIONAmorphousalloysarecharacterizedbyhighwearandcorrosionresistance ,togetherwithmanyspecificphysicalproperties[1,2 ] .Theyhavebeenusedasfunc tionalmaterialsinmanyfieldsextensively .Theamor phousNi Palloyhasbeenappliedtoautomobile[3] ,aircraft,computer ,electronics ,food processing ,petroleum ,andsoon[4 ] .Electrodepositionorelectrolessplatingisoneofthemostsimple ,convenientandeconomicmethodstoobtainvariousamorphousalloys .Themostattractiveamorphousalloysconsistoftheelementsof…     

大功率CO2激光沉积超硬Si3N4膜的性能和组织

用大功率(kW级)CO_2激光在金属基材上通过化学气相沉积获得α-Si_3N_4膜。膜层多为细小的Si_3N_4颗粒组成,与基材有良好的结合,具有超硬和优良的耐磨抗蚀等性能,厚度在5—30μm范围内可控。     

等离子熔覆Mo/Ni基合金涂层的组织结构及耐磨性能

应用光学显微镜、扫描电镜(SEM)、X射线衍射(XRD)、透射电镜(TEM)以及滑动磨损实验,研究不同Mo加入量对等离子熔覆镍基合金涂层组织结构和性能的影响。结果表明,熔覆层主要是由面心立方结构的(γNi,Fe)固溶体、六方结构的M7(C,B)3和四方结构的Cr2B等物相构成,在镍基固溶体中存在明显的成分偏析。Mo的加入没有改变熔覆层的相结构,但硼碳化物的相对含量却有所提高,成分偏析逐渐减弱,直至消失,并且促进了等轴晶的形成。Mo的加入可以提高熔覆层的耐磨性能,当其加入量在6%以内时,随着Mo加入量的提高,熔覆层的耐磨性逐渐提高。但是,当加入量达到8%时,耐磨性能开始降低。