Fe-Mo合金高温硫化产物中的固态反应及传质

以XRD、SEM/WDS和TEM分析结果为依据,对Fe-Mo(Mo=20%～57%)二元合金在硫蒸气中(PS2=1～50kPa)高温硫化产物层的相组成及膜层中的有关固态反应进行了探讨,绘出了可能的稳定相图,分析了主要硫化产物的缺陷结构特点及其对硫化传质的影响.认为Fe、Mo混合硫化物中的缺陷密度较高,对传质的阻力较小;而MoS2层缺陷密度小,对阻止硫化反应物传质起主要作用.     

Sulfidation properties of TiAl–2 at.% X (X=V,Fe, Co,Cu, Nb,Mo, Ag and W) alloys at 1173 K and 1.3 Pa sulfur pressure in an H2S–H2 gas mixture

TiAl–2 at. % X (X=V, Fe, Co, Cu, Nb, Mo, Ag and W) alloys were sulfidized at 1173 K for 86.4 ks at a 1.3 Pa sulfur pressure in an H₂–H₂S gas mixture. The structure, phases, and compositions of the external sulfide scale and alloy surface layer were measured using EPMA and X-RD. The TiAl–2Ag and –2Cu alloys sulfidized faster than TiAl, and the alloy surface layer was thicker than that of TiAl. Sulfidation amounts of the TiAl–2X (X=V, Co, Fe, Mo, W and Nb) alloys were almost the same as that of TiAl, while the thickness of the alloy surface layer decreased in the order: V>Co>Fe>Mo>[Cr (by Narita T, Izumu T, Yatagai M, Yoshioka T. Intermetallics, 2000;8:371)]>W>Nb. The sulfide scale was composed of multi-layer structures: an outermost (rich in Ti-sulfides), an outer (rich in Al₂S₃), an inner (a mixture of Ti-sulfides and Al₂S₃), and an innermost (rich in Ti-sulfides) layer. The alloy surface layer also had a multi-layer structure, and was classified into four groups: group 1 for TiAl–2V and –2Co alloys as well as TiAl binary alloy where the surface layer consists of alloy substrate/TiAl₂/TiAl₃/sulfide scale, group 2 for TiAl–2Nb, –2Mo, and –2W (and also– 2Cr) alloys with alloy substrate/TiAl₂/TiAl₃/(Nb, Mo, W or Cr)–Al alloy/sulfide scale, group 3 for TiAl–2Cu and –2Ag alloys with alloy substrate/TiAl₂/Ti (Al, Ag or Cu)₃ with an L1₂ structure/TiAl₃/sulfide scale, and group 4 for TiAl–2Fe alloy with alloy substrate/TiAl₂/Ti(Al,Fe)₃ with an L1₂ structure/TiAl₃/FeAl₃/sulfide scale. Diffusion paths for these four groups were shown in a tentative Ti–Al–X ternary phase diagram.     

The structure and adhesion of oxide scales on Fe?Ni?Mo and Fe?Cr?Mo alloys

The Structure and Adhesion of Oxide Scales on Fe? Ni? Mo and Fe? Cr? Mo Alloys A preliminary study has been made of the structure and adhesion of oxide scales formed on Fe-1.8 wt.% Ni-0.3wt.% Mo and Fe-1wt.% Cr-0.5wt.% Mo in oxygen at 930°–1250°C. From 930°–1250°C, the Fe? Ni? Mo alloy oxidised at a slower rate that the Fe? Cr? Mo alloy, and both alloys oxidised at a slower rate than high-purity iron. Hot bend tests and hot tensile tests of a scale-metal joint revealed that the scales comprised a strongly adherent inner layer (enriched in Cr? Mo or Ni) and a weakly coherent bulk structure. In the Fe? Ni? Mo alloy, failure in the bulk scale occured along a smooth plane at the edge of the Ni-enrichment zone whereas in contras, for the Fe? Cr? Mo alloy, failure occured withing the Cr? Mo enriched zone adjacent to the scale-metal interface.     

FeWMoCo时效硬化合金的表面冶金工艺（Ⅰ）

利用双层辉光离子渗金属技术可在工业纯铁表面形成铁、钨、钼、钴时效合金。研究了形成这种合金的表面冶金工艺和渗层组织状态、渗层成分分布以及渗金属工艺参数改变对渗层厚度及渗层成分分布的影响。结果表明， 表层Ｗ， Ｍｏ ， Ｃｏ 含量可达到高Ｃｏ 时效合金Ｗ１１ Ｍｏ７Ｃｏ２３ 的水平， Ｃｏ 含量为１８ ％ ～３０ ％ ， Ｗ 含量为７ ％ ～１７ ％ ， Ｍｏ 含量为５ ％ ～９ ％ 。     

Formation and Oxidation Behavior of a Diffusion-Barrier-Coating System on a Ni–Mo base Alloy at 1,373 K in Air

A Ni-aluminide/Re-base diffusion-barrier-coating system and, for comparison, a sole Ni-aluminide coating were formed on the Ni–Mo based alloy Hastelloy-X, and the oxidation behavior of the coated alloys was investigated in air at 1,100 °C for up to 400 h. After 100 h of oxidation the diffusion-barrier-coating system consisted of a duplex structure comprised of an inner σ-(Re, Mo, Cr, Ni) and an outer β-NiAl layers and covered by a protective Al₂O₃ scale. By contrast, the Ni-aluminide coating had degraded, forming a reaction diffusion zone, γ-Ni(Cr, Mo, Fe, Al), with voids, and the external scale exfoliated extensively. After 400 h of oxidation of the diffusion-barrier-coating system, an intermediate reaction-diffusion zone was present. The Mo of the alloy substrate was enriched in the inner σ-layer, changing it from a Re-base alloy to a Mo-base alloy. The Mo-base alloy appeared to enhance both inward-Al diffusion and outward diffusion of alloying elements such as Mo, Fe, and Cr to form the intermediate reaction-diffusion zone. The outer layer consisted mainly of β-NiAl with channels of γ-Ni(Cr, Mo, Fe, Al). It was concluded that the Re-base alloy such as a σ-phase in the Ni–Cr–Re system acts as an effective diffusion-barrier layer, but that this is not the case for the Mo-base alloy layer.     

稀土镝对钨钼合金渗层的影响

利用等离子表面冶金技术对20钢进行W-Mo-Dy和W-Mo共渗。对合金渗层的硬度、金相组织、截面形貌、合金元素的分布和相结构进行检测和观察。结果表明:W-Mo-Dy共渗和W-Mo共渗合金渗层的表面硬度分别为347 HV0.05、294 HV0.05,合金层厚度分别为128μm、107μm,合金渗层与基体之间均存在反应扩散线,W-Mo-Dy共渗合金渗层组织较W-Mo共渗合金层组织晶粒细小,W-Mo-Dy共渗合金层基本相结构由(W、Mo、Dy)在Fe中固溶体、Dy2O3和少量的DyFe10Mo2组成;W-Mo共渗合金层共渗层基本结构为(W、Mo)在Fe中固溶体组成。W-Mo-Dy共渗合金层表面的[W]当量为24.79%,W-Mo共渗合金层表面[W]当量为18.4%;稀土镝具有明显的促渗、改善合金渗层组织的作用。     

空位缺陷对单层MoS_2电子结构的影响

为了研究单层Mo S2中的空位缺陷形成及其对电子结构的影响,基于密度泛函理论框架下的第一性原理,采用平面波赝势方法分别计算了单层Mo S2中Mo空位和S空位的形成能、空位附近的晶格畸变、Mo S2层中的电子分布以及态密度(DOS)和能带结构。计算结果显示,2种空位缺陷都具有点缺陷特征,其附近的电子分布呈现出明显的局域化特点,且S空位比Mo空位更容易形成。通过与本征态Mo S2电子结构的对比分析,发现2种空位缺陷的存在对单层Mo S2的电子结构、尤其是对导带高能量区域的能态密度会产生十分明显的影响,这些影响可能与空位缺陷引入的缺陷能级有关。     

Effects of Mo substituted Nb on magnetic properties of Finemet alloy

Different Mo contents have been added into traditional Finemet alloy to form Fe73.5Cu1Nb3-x MoxSil3B9.5( x = 0 - 3) alloys. The change in DC and AC magnetic properties with Mo for Nb substimtlon was investigated. The results show that, with adding Mo, although the DC relative permeability decreases and the coercive force increases slightly,the saturation flux density Bs can be increased, and the core loss of the alloy can be decreased. The AC permeability of samples contained Mo is higher than that of alloy without Mo content. Fe73.sCu1Nb1Mo2Si13B9.5 alloy has the highest saturation flux density Bs. Fe73.sCu1Nb2Mo1Si13B9.5 alloy has the best frequency dependence on the AC permeability and core loss.     

MoSz在空间对接摩擦材料烧结过程中的行为变化

采用粉末冶金技术制备了空间对接用铜基摩擦材料，利用X射线衍射及定量化学分析技术对MoS2在材料烧结过程中的变化行为及与其他组元之间的作用进行研究。结果表明，MoS2在加压烧结过程中存在三个方面的反应：在高温下分解成Mo和S,并造成了S元素的损失；与Cu作用形成了复杂的铜钼硫化合物；与Cu反应生成了Cu的硫化物，该类化合物具有与MoS2相类似的层状结构，有一定的润滑作用。MoS2高温分解后或MoS2与Cu反应产生的Mo元素与石墨反应形成了Mo的碳化物。另外，双飞粉的加入不仅与材料中的Mo元素作用形成CaMoO4并且改变了铜钼硫化合物、Cu的硫化物以及Mo的碳化物中各元素的麾尔比。     

磁控溅射制备TiWN/MOS2薄膜及其微观结构和摩擦学性能研究

采用磁控溅射方法在40Gr不锈钢基体上,沉积了TiN及TiWN单层薄膜、TiN/MoS2及TiWN/MoS2双层薄膜,对比分析了薄膜的成分、相结构、微观形貌及摩擦学性能.结果表明:根据W含量的不同,TiWN薄膜中,Ti0.67W0.33N膜层具有较高的硬度和弹性模量;TiWN/MoS2薄膜中,TiWN层主要含有TiN和...     

钛合金表面MoS2-Ti/Cu-Ni-In多层固体润滑膜的制备及其抗微动磨损性能

目的改善钛合金表面抗微动磨损性能。方法利用非平衡磁控溅射技术在钛合金表面沉积MoS_2-Ti/Cu-Ni-In多层固体润滑膜,并与MoS_2-Ti与Cu-Ni-In单层固体润滑膜进行对比。利用扫描电镜、显微硬度计、摩擦磨损试验机、表面轮廓仪对固体润滑薄膜的形貌、硬度、抗微动磨损性能、磨痕形貌进行分析测试。结果所制备的Cu-Ni-In单层膜与MoS_2-Ti单层膜结构致密,与基体结合良好,MoS_2-Ti/Cu-Ni-In多层膜交替结构清晰,结构致密。MoS_2-Ti/Cu-Ni-In多层膜的硬度大于MoS_2-Ti及Cu-Ni-In单层膜,多层膜的平均微动系数为0.06,MoS_2-Ti单层膜的平均微动系数为0.102,Cu-Ni-In单层膜的平均微动系数大于1.0。在12 000个微动循环周期后,测得MoS_2-Ti/Cu-Ni-In多层膜的最终磨损总量为0.045 mm~3,Cu-Ni-In单层膜的最终磨损总量为37.79 mm~3,MoS_2-Ti单层膜的最终磨损总量为0.296 mm~3,即多层膜的抗微动磨损性能较Cu-Ni-In单层膜改善了2个数量级,较MoS_2-Ti单层膜改善了5倍以上。结论 MoS_2-Ti/Cu-Ni-In多层膜中的多个界面对单层晶粒生长起到了阻挡作用,从而致使交替结构中的单层晶粒得到细化,Cu-Ni-In膜的引入延缓了MoS_2-Ti膜的剥落及其转移,增加了不锈钢球与多层膜间第三体的润滑及减磨效果,多层膜表现出了优异的抗微动磨损性能。     

High Temperature Corrosion of the Alloy Ni4Mo in a hydrogen chloride atmosphere

Specimens of the alloy Ni₄Mo were tested in a hydrogen chloride atmosphere at temperatures between 400° – 850° C. The corrosion of the alloy was followed by gravimetric analyses and microstructural examinations. It was found that the layer formed on the specimens due to corrosion is adherent but porous, thus allowing the volatilization of some of the corrosion products. The formation of various kinds of oxides and chlorides was observed. The exact composition of the scale depended on the temperature of exposure to hydrogen chloride and on the amount of oxygen present as an impurity in the test apparatus. The formation of a domain structure in the uncorroded alloy affects the morphology of the scale/alloy interface.     

Improving Corrosion Resistance of Ferrous Alloy to Molten Zn by Modifying the Laves Phase Characteristics

The Laves phase morphology in the Fe25Mo14Cr10Ni1Si (wt.%) alloy was modified by Si addition to improve the corrosion resistance of the ferrous alloy to molten zinc. The Si-containing alloy showed a woven, needle-like Laves phase with higher Mo content than that of the Fe25Mo14Cr10Ni alloy. Corrosion resistance to molten Zn for the Si-containing alloy was more than 20 times higher than that of the silicon-free alloy mainly as a result of the characteristics of the modified Laves phase. This phase was oriented perpendicular to the Zn-diffusion direction, which effectively prevented corrosion by the molten Zn, leading to a denser FeZn₁₃ layer rather than the FeZn₁₀ layer produced in the Fe25Mo14Cr10Ni alloy.     

钼对铁基合金等离子熔覆层组织及耐磨性能的影响

应用光学显微镜（OM）、扫描电镜（SEM）、X射线衍射（XRD）、透射电镜（TEM）和磨粒磨损试验,研究了质量分数为4％的钼对等离子熔覆铁基合金涂层组织结构和耐磨性能的影响。结果表明,未加钼的铁基合金熔覆层主要由面心立方结构的γ-（Ni,Ve）固溶体、正交结构的（Cr,Fe）7C3和四方结构（Cr,Fe）2B等物相构成,组织为粗大的亚共晶。4％Mo的加入,不但使熔覆层中出现了立方结构的M23C6和正交结构的Mo2C,而且增加了共晶化合物相的相对含量。添加4％Mo的熔覆层呈伪共晶特征,组织得到显著细化。4％Mo的加入所引起的新相析出和组织细化是铁基熔覆层耐磨性提高的原因。     

TC4钛合金表面微弧氧化原位生长自润滑MoS2/TiO2膜层研究

钛合金表面减摩涂层的设计和制备是提升钛合金构件耐磨性能、保障服役安全的重要技术之一。针对于目前钛合金减摩涂层中减摩剂分散不均匀，易于团聚导致膜基结合力差等问题，本论文采用一步微弧氧化技术在TC4合金表面原位生长纳米MoS2颗粒，制备具有减磨作用的MoS2/TiO2复合陶瓷膜层；讨论了原位反应中硫源添加量对膜层微观结构及耐磨性能的影响。结果表明：以Na2S和Na2MoO4分别为硫源和钼源在TC4合金表面通过微弧氧化制备出了MoS2/TiO2复合陶瓷膜层；通过控制Na2S浓度可以原位生成具有小尺寸、均匀化分布的纳米MoS2颗粒，并实现对MoS2含量和形态的调控。随着Na2S浓度的增加，膜层结构逐渐致密化且表面粗糙度较低，当添加量到达60g/L时，由于硫沉淀作用导致膜层开始疏松，粗糙度增加。由于膜层表面和内部均存在均匀化分布且具有自润滑作用的MoS2颗粒，所得膜层耐磨性较传统微弧氧化膜层或直接添加MoS2颗粒所得膜层分别提高了395.4%、129.4%；同时，膜基结合力较传统微弧氧化提高了87.1%，达到了723.8N，说明了该技术在保证良好的自润滑效果同时改善了膜基结合力。该研究结果可以为钛合金耐磨涂层设计和制备提供新思路和研究方法。     

Methods for controlling the composition and morphology of electrodeposited Fe–Mo and Fe–Co–Mo coatings

The effect of the electrolyte composition and the stationary electrolysis parameters on the composition and morphology of Fe–Mo and Fe–Co–Mo coatings deposited from complex citrate electrolytes based on Fe(III) is studied. It is shown that, at a constant component ratio of с(Fe³⁺): с(Co²⁺): с(MoO^2? ₄): с(Cit^3–) = 2: 2: 1: 4, an increase in the electrolyte concentration leads to a decrease in the pH of the solution in a range of 4.85–4.30 and in the molybdenum content in the coating. An increase in the current density contributes to the molybdenum enrichment of the electrodeposited alloy in the entire range of electrolyte concentrations. The Fe–Mo alloy coatings have a rough microporous surface; an increase in the current density does not lead to significant changes in the surface topography. It is found that the formation of ternary coatings is characterized by the competitive reduction of iron and cobalt in the alloy; the molybdenum content depends on the current density. At a metal ratio of 3: 2: 1 and a molybdenum content of up to 17 at % in the Fe–Co–Mo alloy, the surface has a fine-grained needlelike structure typical of cobalt. With an increase in i _c, the atomic fraction of molybdenum increases, while the surface becomes microglobular. The Fe–Co–Mo electrodeposits with a metal ratio of 2.5: 1.5: 1.0 and a molybdenum content of 19–20 at % have a more developed surface with a high density of spheroids.     

配电变压器用铁基非晶合金成分的研究

在２６０５Ｓ－２非晶合金成分基础上,小范围调整了合金成分,主要是用铁替代硅和硼设计出三种合金,研究了成分对合金性能的影响。其中Ｋ２炉号合金综合性能比２６０５Ｓ－２合金要好,可作为改进成分进行深入研究。     

Surface structure and catalytic activity of electrodeposited Ni-Fe-Co-Mo alloy electrode by partially leaching Mo and Fe

1 Introduction The chlorine alkaline industry and the production of hydrogen by electrolyzing water have disadvantages of high cost and energy consumption, so it is especially important to study and develop a high catalytic activity and good stability el…     

钛钼合金在盐酸溶液中形成的钝化膜研究

应用XPS和电化学测量技术研究了Ti-15Mo合金在70℃的1mol/L和4mol/LHCl溶液中不同阳极极化条件下生成的钝化膜。结果表明,钝化膜是双层结构,由表层和过渡层组成。在低极化电位(0.000和-0.100V)下膜表层较厚(4nm),富集Mo。在高极化电位(+0.900V)下膜表层较薄(2nm),贫Mo。在钝化膜内含有较多Cl~-,而且Cl~-分布很深。推测Cl参加了膜的生成反应,生成了Ti和Mo的含氯和氧的化合物。     

IN DEPTH PHASE ANALYSIS OF BORONIZED LAYER ON ALLOYS BY GLOW DISCHARGE OPTICAL EMISSION SPECTROSCOPY

用辉光光谱分析测出了纯Fe,45钢,Cr12Mo工具钢,Cr26Mo和Cr18Ni9Ti不锈钢的渗硼层中硼与合金元素的分布规律。根据测得的硼和合金元素的含量,计算了渗硼层中硼化物相的组成。经X射线衍射分析证明,计算结果是可靠的。