Interface microstructure and properties of submerged arc brazing tin-based babbit

The submerged arc brazing method was used to connect the tin-based babbit alloy with the steel matrix.The microstructure of the submerged arc brazed Babbitt interface layer on the surface of Q235 B steel was analyzed by OM,SEM and EDS and the hardness properties of the joint interface layer were tested by MH-5 microhardness tester.the result of research shows that a layer of canine-shaped intermetallic compound with uneven thickness is formed at the interface,and the thickness is 10-20 μm.The interface layer includes two kinds of compound layers,namely the Fe Sn layer near the side of the steel substrate and FeSn layer near the side of the babbit.During the interfacial reaction process,Fe atoms in the steel matrix dissolve into the liquid babbit alloy and form a certain concentration gradient at the interface.The farther from the interface,the lower the Fe atom concentration.The growth of Gibbs free energy of Fe Sn is lower when the temperature is above 780.15 K,and the temperature during the welding process is much higher than 780.15 K,moreover the precipitation temperature of Fe Sn is higher.Therefore,in the subsequent cooling process,Fe Sn is first precipitated from the interface near the side of steel matrix and then FeSn is precipitated from the interface near the side of babbit alloy.Microhardness test showed that the intermetallic compound at the interface layer significantly improved the hardness properties.

Investigation of an electrode-driven hydrogen plasma method for in situ cleaning of tin-based contamination

To prolong the service life of optics,the feasibility of in situ cleaning of the multilayer mirror(MLM)of tin and its oxidized contamination was investigated using hydrogen plasma at different power levels.Granular tin-based contamination consisting of micro-and macroparticles was deposited on silicon via physical vapor deposition(PVD).The electrodedriven hydrogen plasma at different power levels was systematically diagnosed using a Langmuir probe and a retarding field ion energy analyzer(RFEA).Moreover,the magnitude of the self-biasing voltage was measured at different power levels,and the peak ion energy was corrected for the difference between the RFEA measurements and the self-biasing voltage(E_(RFEA)-eV_(self)).XPS analysis of O 1s and Sn 3d peaks demonstrated the chemical reduction process after 1 W cleaning.Analysis of surface and cross-section morphology revealed that holes emerged on the upper part of the macroparticles while its bottom remained smooth.Hills and folds appeared on the upper part of the microparticles,confirming the top-down cleaning mode with hydrogen plasma.This study provides an in situ electrode-driven hydrogen plasma etching process for tin-based contamination and will provide meaningful guidance for understanding the chemical mechanism of reduction and etching.

Chlorofullerene C_(60)Cl_(6) Enables Efficient and Stable Tin-Based Perovskite Solar Cells

Tin-based perovskite solar cells(TPSCs)have received great attention due to their eco-friendly properties and high theoretical efficiencies.However,the fast crystallization feature of tin-based perovskites leads to poor film quality and limits the corresponding device performance.Herein,a chlorofullerene,C_(60)Cl_(6),with six chlorine attached to the C_(60)cage,is applied to modulate the crystallization process and passivate grain boundary defects of the perovskite film.The chemical interactions between C_(60)Cl_(6)and perovskite components retard the transforming process of precursors to perovskite crystals and obtain a high-quality tin-based perovskite film.It is also revealed that the C_(60)Cl_(6)located at the surfaces and grain boundaries can not only passivate the defects but also offer a role in suturing grain boundaries to suppress the detrimental effects of water and oxygen on perovskite films,especially the oxidation of Sn^(2+)to Sn^(4+).As a result,the C_(60)Cl_(6)-based device yields a remarkably improved device efficiency from 10.03%to 13.30%with enhanced stability.This work provides a new strategy to regulate the film quality and stability of TPSCs using functional fullerene materials.

Microstructure and tribological behavior of tungsten inert gas welding arc brazing tin-based babbit

The microstructure of the tin-based babbit obtained by the method of tungsten inert gas welding(TIG)arc brazing was studied by optical microscopy(OM)and X-ray diffraction(XRD).Tribological behavior was investigated by high-temperature friction and wear testing machine(HTFWT),laser scanning confocal microscopy(LSCM),scanning electron microscopy(SEM)and energydispersive spectrometer(EDS).It can be found that the higher welding current of the melting tin-based babbit makes it possible to form isomer structure with fine crystals of the cubic SnSb compounds and large star Cu6Sn5 compounds so that a higher hardness can be achieved,and a lower wear rate can be obtained over the entire distance of sliding friction.When the applied load is 2 N,the contact surface is oxidized due to the accumulation of friction heat and oxide,which plays a role of lubricated film.Also,the softer Sn-based solid solution forms obvious furrow under abrasive wear,and the harder SbSn and Cu6Sn5 intermetallic compounds shatter and leave a hole under friction.

Propylamine hydrobromide passivated tin-based perovskites to efficient solar cells

The development of tin-based devices with low toxicity is critical for the commercial viability of perovskite solar cells.However because tin halide is a stronger Lewis acid,its crystallization rate is extremely fast,resulting in the formation of numerous defects that affect the device performance of tin-based perovskite solar cells.Herein,propylamine hydrobromide(PABr)was added to the perovskite precursor solution as an additive to passivate defects and fabricate more uniform and dense perovskite films.Because propylamine cations are too large to enter the perovskite lattices,they only exist at the grain boundary to passivate surface defects and promote crystal growth in a preferred orientation.The PABr additive raises the average short-circuit current density from 19.45 to 25.47 mA·cm^(-2)by reducing carrier recombination induced by defects.Furthermore,the device’s long-term illumination stability is improved after optimization,and the hysteresis effect is negligible.The addition of PABr results in a power conversion efficiency of 9.35%.

A new Tin-based O3-Na_(0.9)[Ni_(0.45-x/2)Mn_xSn_(0.55-x/2)]O_2 as sodium-ion battery cathode

Recently,sodium-ion batteries(SIBs),regarded as promising supplements for lithium-ion batteries(LIBs),especially in the large-scale energy storage field,are attracting more and more attention.However,the limited suitable cathode materials hinder the wide commercialization of SIBs.Given this aspect,in this work,a new layered oxide with 4d metal Tin was synthesized and investigated as cathode material for SIBs.Two optimized sodium-deficient O3-Na_(0.9)Ni_(0.45)Sn_(0.55)O_2and O3-Na_(0.9)Ni_(0.4)Mn_(0.1)Sn_(0.5)O_2were selected for comprehensive investigation,both of which exhibited high operating voltage of around 3.45 V with smooth charge/discharge curves.In comparison,O3-Na_(0.9)Ni_(0.4)Mn_(0.1)Sn_(0.5)O_2shows a higher reversible capacity(65 m A h/g,0.1 C),better rate capability and cycling stability than that of O3-Na_(0.9)Ni_(0.45)Sn_(0.55)O_2(50 mA h/g,0.1 C),indicating that a small amount of Mn-substitution can improve the electrochemical performance.This work presents a new possibility of discovering potential cathode candidates by exploring the Tin-based layered oxides.

Interfacial engineering in lead-free tin-based perovskite solar cells

Lead(Pb)-free Tin(Sn)-based perovskite solar cells(PSCs)have been favored by the community due to their low toxicity,preferable bandgaps,and great potential to achieve high power conversion efficiencies(PCEs).Interfaces engineering plays important roles in developing highly efficient Sn-based PSCs via passivation of trap defects,alignment of energy levels,and incorporation of low-dimensional Sn-based perovskites.In this review,we summarize the development of Pb-free Sn-based perovskites and their applications in devices,especially the strategies of improving the interfaces.We also provide perspectives for future research.Our aim is to help the development of new and advanced approaches to achieving high-performance environment-friendly Pb-free Sn-based PSCs.

Influence of charge transport layer on the crystallinity and charge extraction of pure tin-based halide perovskite film

As one of the most compelling photovoltaic devices, halide perovskite (PVK) solar cells have achieved a new surprising record power conversion efficiency (PCE) of 25.8%in 2021 [1]. This demonstrates the great potential of halide PVK solar cells as a highly competitive substitute to replace silicon-based solar cells in the photovoltaic market [2–6].

Potassium thiocyanate additive for PEDOT:PSS layer to fabricate efficient tin-based perovskite solar cells

The commercialized poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)is usually used as hole transport layers(HTLs)in tin-based perovskite solar cells(TPSCs).However,the further development has been restricted due to the acidity that could damage the stability of TPSCs.Although the PEDOT:PSS solution can be diluted by water to decrease acidity and reduce the cost of device fabrication,the electrical conductivity will decrease obviously in diluted PEDOT:PSS solution.Herein,potassium thiocyanate(KSCN)is selected to regulate the properties of PEDOT:PSS HTLs from the diluted PEDOT:PSS aqueous solution by water with a volume ratio of 1:1 to prepare efficient TPSCs.The effect of KSCN addition on the structure and photoelectrical properties of PEDOT:PSS HTLs and TPSCs have been systematically studied.At the optimal KSCN concentration,the TPSCs based on KSCN-doped PEDOT:PSS HTLs(KSCN-PSCs)demonstrate the champion power conversion efficiency(PCE)of 8.39%,while the reference TPSCs only show a champioan PCE of 6.70%.The further analysis demonstrates that the KSCN additive increases the electrical conductivity of HTLs prepared by the diluted PEDOT:PSS solution,improves the microstructure of perovskite film,and inhibits carrier recombination in TPSCs,leading to the reduced hysteresis effect and enhanced PCE in KSCN-PSCs.This work gives a low-cost and practical strategy to develop a high-quality PEDOT:PSS HTLs from diluted PEDOT:PSS aqueous solution for efficient TPSCs.

面向高速工况的轴承材料成形工艺

针对高速工况下轴承巴氏合金耐温性能及机械性能偏低等问题,用公理设计理论研究了巴氏合金轴瓦成形新工艺。通过在锡基巴氏合金中添加微量Cu及对冷却速度的控制,改进了原有工艺。浇铸件的材料力学和摩擦磨损测试表明:使用新工艺后,巴氏合金材料的耐温性能、抗压缩性能和结合性能获得了增强,减摩抗磨性能得到了提高。在高速试验台上对新工艺轴承进行了初步试验考核,试验轴承运行平稳,各项指标满足高速工况的使用要求。

巴氏合金干滑动摩擦磨损机制分析

以巴氏合金(ZChSnSb11-6)和45#钢为摩擦副,在SST-ST销盘式摩擦试验机下进行干摩擦试验,采用超景深三维显微镜、SEM、XRD对巴氏合金试样的摩擦表面进行表征,探讨其磨损机制。结果表明:干摩擦条件下,巴氏合金的摩擦因数较大,且波动较大;干摩擦条件下巴氏合金试样表面的物相发生明显变化,且试样表面同时存在磨粒磨损、氧化磨损和应变疲劳剥落。

巴氏合金材料浇铸工艺及质量检测的数据化研究

为使巴氏合金轴瓦浇铸的过程控制具有真实有效的科学决策依据,促进浇铸过程的标准化和规范化,在滑动轴承轴瓦浇铸中引入"数据化"概念。提取并分析巴氏合金浇铸环节中的数据,设计数据可观测、浇铸过程可控的浇铸系统;研究与轴承制造质量密切相关的数据,设计制造质量检测平台。

锡基巴氏合金涂层火焰喷涂工艺

通过实验确定影响火焰喷涂锡基巴氏合金涂层质量的主要工艺参数 ,采用碳化焰、送丝速度在 10m/min左右、轴向辅助吹风及相应喷涂操作技巧 。

Mg_6Si_4O_(10)(OH)_8修复剂应用于滑动轴承的模拟试验研究

采用模拟轴承试验机,考察在设计的试验条件下金属磨损自修复层在45#钢/巴氏合金摩擦副间的原位生成及其摩擦学性能。润滑剂使用含适量Mg6Si4O10(OH)8修复剂的SD/CC 40汽油机/柴油机通用油。27 h摩擦试验结束后,采用表面形貌仪、扫描电镜和显微硬度计分析摩擦表面。结果表明,在45#钢表面形成了约2μm厚的自修复层,2个摩擦副表面的表面形貌均有明显改善;显微硬度均有一定的提高,金属磨损自修复层表现出优良的抗磨粒磨损和抗粘着磨损的性能。

提高离心浇铸巴氏合金轴瓦质量的研究

通过对加镉、镍等元素的锡基轴承合金的金相组织、相成分、显微硬度的分析,以及合金的各项物理、力学性能试验,对含镉镍巴氏合金与传统巴氏合金作了比较.同时,对取得优良的铸造轴瓦所必需的结构、设计和离心浇铸工艺进行了探索并取得了实际数据.

大型立式水泵机组推力瓦性能分析及改进设计

分析了大型立式水泵机组中主电动机推力瓦的性能,以此来阐明江都水利枢纽第四泵站主电动机巴氏合金推力瓦的烧损故障原因.结合机组本身的实际情况,采用弹性金属塑料瓦替代巴氏合金瓦,对电机推力瓦进行改进设计.根据弹性金属塑料瓦的实际应用情况,通过与巴氏合金瓦进行比较分析,提出了弹性金属塑料瓦的优点及其使用注意事项.实践证明:改进设计后,在瓦面质量合格的情况下,机组运行稳定,瓦温保持在30℃左右(此时冷却水温度为20℃左右);该站首台使用塑料瓦的7号机组已安全运行20 000 h以上,瓦面平均磨损量小于0.05 mm,基本上消除了出现烧瓦故障的可能性.

弹性金属塑料瓦的使用效益分析

前苏联自１９７４年以来，在水电站广泛采用了弹性金属塑料瓦推力轴承，国内自１９９０年起，也陆续在一些大、中、小型水电站采用弹性金属塑料瓦推力轴承，国内外一些电站运行的成功经验表明，使用弹性金属塑料瓦，能够提高水电站安全、稳定、经济运行水平，减少或消灭水电站“烧瓦”事故，减少停机、停车损失，具有巨大的社会和经济效益．

国电谏壁发电厂8号机主油泵故障分析及处理

对8号机组主油泵故障及其处理过程进行了介绍。检查分析认为,主油泵故障最主要的原因为发电机轴电压过高并在主油泵处形成轴电流,导致主油泵轴承电腐蚀及磨损,通过采取加强接地碳刷、润滑油过滤和除水等措施,抑制了轴电流对主油泵的侵蚀,取得了较好的效果。

巴氏合金变质处理的绿色方法

功率超声具有独特的变质作用 ,是一种绿色无污染的环保型变质处理方法。研究了功率超声对巴氏合金凝固过程的影响。结果表明 ,在巴氏合金的凝固过程中导入功率超声 ,能够显著细化巴氏合金组织 ,但随超声功率增大 ,热效应变明显 ,合金凝固后的组织又变得粗大。根据该结果 ,分析了功率超声变质细化的机理。

超超临界机组汽轮机轴瓦失效分析

对某电厂某机组#1轴瓦发生脱胎的巴氏合金进行了化学成分分析、金相组织分析、XRD分析和X射线能谱分析等测试。分析结果显示,Sb含量符合要求,Cu,Pb,Zn含量均超标;巴氏合金组织中β′相(SnSb)在个别位置存在的轻度偏析,但未发现严重的偏析、分层及其他铸造缺陷;ε相(Cu6Sn5)和β′相(SnSb)两相之和所占比例平均值为39.5%;在结合面处挂锡层的合金侧有ε层。建议同类部件的订货协议中应明确提出允许的化学成分偏差范围及合金层硬质相含量要求。