Ti/AlN/Ti/AlN复合涂层的制备和阻氘性能研究

为提高AlN涂层的稳定性和阻氚性能,提出“Ti-AlN”复合结构涂层。采用磁控溅射法在316L不锈钢基体表面制备了结构致密、总厚度约500 nm的Ti/AlN/Ti/AlN复合涂层。对涂层样品进行不同的真空热处理后,采用SEM、XRD、AES等手段分析涂层样品在热处理前后的微观形貌和结构变化,并对样品在200-600 ℃的阻氘性能进行测试和分析。结果表明,仅热处理温度为760 ℃时,Ti-AlN界面反应生成少量的Al3Ti相。在所有涂层样品中,热处理温度为700 ℃、升温速率为1.5 ℃/min的复合涂层表现出最优的阻氘性能,其600 ℃的PRF（Permeation Reduction Factor）高达536。当热处理温度升高至760 ℃或升温速率达到2.5 ℃/min时,表层AlN层的开裂程度更为严重,并导致涂层的阻氘性能显著降低。另外,所有涂层样品的PRF（阻氘性能）均随渗透温度的降低而急剧减小,表明氘气渗透过程中的温度变化会导致复合涂层阻氘性能失效。     

Al2O3/Au/Al2O3层状阻氚薄膜

采用磁控溅射法在316L不锈钢基体上分别沉积单层Al2O3膜、单层Au膜以及Al2O3/Au/Al2O3层状薄膜。采用气相渗透法在500℃,氘分压为0.06 MPa条件下测试了薄膜的阻氘性能。结果表明,3种薄膜氘渗透后,薄膜的形貌良好,无开裂、无剥落的现象,氘渗透率减低因子均比316L不锈钢基材增大一个数量级以上,阻氘效能按单层Al2O3膜、单层Au膜以及Al2O3/Au/Al2O3层状薄膜依次递升。Al2O3/Au/Al2O3层状薄膜的优异阻氘效能可归因于,延性的Au夹层使层状薄膜的力学性能得到显著提高;Al2O3层能阻止Au与基体间互扩散,使Au能充分发挥阻氘效能。本研究表明,由贵金属与陶瓷阻氚材料构成的层状薄膜是发展阻氚涂层的新途径。     

(Ni-P)/（TiO2/ZnO）复合涂层的制备及其在天然海水中的耐蚀性

采用化学镀和溶胶-凝胶技术在碳钢表面制备了(Ni-P)/(TiO2/ZnO)复合涂层。采用光学显微镜、扫面电镜观察涂层表面形貌;采用能谱及X射线衍射技术分析涂层的成分和相组成;采用电化学极化曲线及阻抗谱评价涂层在天然海水中的耐蚀性。结果表明,(Ni-P)/(TiO2/ZnO)复合涂层较之Ni-P涂层具有更好的耐海水腐蚀性能;在Ni-P涂层表面直接制备TiO2/ZnO复合薄膜并进行350℃热处理所获得的复合涂层具有最优的耐天然海水腐蚀性能。     

304不锈钢表面制备Ni-P-B复合镀层

采用化学镀法在304不锈钢表面制备了Ni-P-B复合镀层,研究了该镀层在250、300、350、400、450℃处理后的硬度和耐腐蚀性;对镀层的形貌、元素含量进行了分析;对该镀层在硫酸中的腐蚀机理进行了讨论.结果表明,在350℃处理1h的Ni-P-B具有最佳硬度;在250℃热处理的具有最低腐蚀速率.     

多壁纳米碳管/TiO2复合薄膜的制备与光阴极保护性能研究

用溶胶凝胶旋涂工艺在304不锈钢表面制备了多壁纳米碳管MWCNT/TiO₂复合薄膜,用X射线衍射技术和电子显微技术研究了复合薄膜的物相组成与显微形貌,同时采用电化学分析手段,分别在250 W紫外灯和28 W节能灯的照射下,表征了MWCNT/TiO₂复合薄膜在3% NaCl溶液和海水介质中对304不锈钢的光阴极防腐蚀性能。研究结果表明,经450℃煅烧和加入管径为20~40 nm纳米碳管制备的MWCNT/TiO₂复合薄膜,不论是在紫外光还是白光激发下都表现出了比纯TiO₂薄膜更加优良的光电性能。同时也表明在3% NaCl溶液和海水介质中纳米碳管的引入都可有效增强TiO₂薄膜对304不锈钢的光阴极防腐蚀性能。     

304不锈钢表面ZnO/TiO2复合薄膜的制备与光生阴极防腐蚀性能研究

采用溶胶-凝胶法和旋涂技术在304不锈钢表面制备了纳米Zn O/Ti O2复合薄膜,使用XRD和SEM对复合薄膜的晶体结构和表面形貌进行了表征。采用电化学分析手段研究了薄膜的复合方式和煅烧温度对复合薄膜光电性能的影响,考察了复合薄膜在3.0%Na Cl溶液中对304不锈钢的光阴极保护性能。结果表明,采用分层制备和分步煅烧工艺制备的Zn O/Ti O2复合薄膜具有优良的光电性能,在紫外光激发下对304不锈钢的光阴极保护性能要显著优于单一Ti O2薄膜和Zn O薄膜。     

离子渗氮AISI 420马氏体不锈钢耐蚀行为研究

采用不同温度对AISI 420马氏体不锈钢进行离子渗氮处理.借助光学显微镜和X射线衍射(XRD)技术分析了渗氮层的微观组织结构,利用显微硬度计测试了渗氮层的硬度分布,通过电化学极化曲线测试和盐雾腐蚀试验研究了离子渗氮AISI 420不锈钢在模拟工业环境中的腐蚀行为.结果表明:AISI 420不锈钢350℃低温离子渗氮层由ε-Fe3N和N过饱和固溶体αN相组成,其化学稳定性高,加之固溶Cr元素的联合作用,明显提高了AISI 420不锈钢基材的腐蚀抗力.AISI 420钢经450℃和550℃渗氮处理,渗氮层中的αN分解成了α相和CrN,造成基体贫Cr,降低了基材的耐蚀性能.马氏体不锈钢低温离子渗氮处理不仅可以提高表面硬度,而且可以获得良好的耐蚀性能.     

退火温度对锗薄膜光学性能和表面结构的影响

研究了退火温度对电子束蒸发制备的锗薄膜光学性能和表面结构的影响规律.在硅基底上制备了厚度约850 nm的Ge薄膜,分别在350、400、450和500℃下进行退火.通过红外光谱仪测试了薄膜的透射率变化,采用光谱反演法得到了薄膜折射率和消光系数的变化规律,使用X射线衍射和原子力显微镜测试了样品的结晶特性和表面形貌.结果 ...     

铁氧体表面Cr/Ni/Ag复合薄膜制备及性能研究

目的利用真空镀膜技术对铁氧体电磁感芯表面进行金属化处理,对金属薄膜的结构及性能进行综合分析,为其实现工程应用提供一定的理论基础。方法采用多腔一体式磁控溅射设备在铁氧体磁体表面依次沉积Cr、Ni、Ag,作为铁氧体表面复合金属薄膜。采用扫描电镜对复合薄膜表面、截面形貌进行表征;利用原子力显微镜对复合薄膜表面粗糙度进行测量;利用划格法对复合薄膜附着力进行测试;利用冲压试验对复合薄膜剥离强度进行测试;利用拉伸试验对复合薄膜结合强度进行测试;利用浸锡试验对复合薄膜耐焊性进行测试。结果试验制备的Cr/Ni/Ag复合薄膜各层厚度分别为420、4200、550 nm,Cr层与Ni层有明显柱状晶结构,层间界面清晰、无明显孔隙,Ag层与Ni层紧密结合。复合薄膜表面粗糙度为13 nm,附着力达0B级,结合力为30 N,抗拉强度达42 MPa。复合薄膜经过450℃浸锡18 s后,表面金属薄膜无脱焊或露底。结论采用磁控溅射技术制备的Cr(420 nm)/Ni(4200 nm)/Ag(550 nm)复合金属薄膜结构致密均匀,综合性能优异,达到铁氧体电感磁芯表面金属薄膜技术要求。     

低温等离子复合技术制备氧化铝阻氚涂层（英文）

采用低温等离子复合技术,先后经过磁控溅射镀铝,热处理及氧离子注入,在不锈钢基体上制备了氧化铝阻氚涂层。利用XRD、SEM、EDS、AES对涂层进行了相结构、表面形貌、成分、氧元素分布等分析,并进行了划痕试验、抗热震及阻氚性能测试。结果表明:磁控溅射获得了高质量的铝涂层,热处理后形成了Fe Al合金过渡层。在氧离子注入中,当注入剂量不变电压增加时,离子注入深度增加,而氧元素分布梯度降低;当注入剂量达到8×10~(17) ions/cm~2以上时,氧元素分布变得均匀。所获得的氧化铝涂层具有较好膜/基结合力、抗热震性能及阻氚性能。经过叠加电压注入且剂量达到8×10~(17) ions/cm~2的膜层具有最好的阻氚性能,在600℃能使不锈钢的氚渗透率降低3个数量级。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。