表面热功能结构制造领域的发展及关键技术

正等离子体电解氧化技术以等离子体液相烧结理论为基础,通过阳极化反应并形成相转化,在轻金属表面生成具有特殊微观结构的氧化膜。通过氧化膜纳米孔阵列微结构可控,使氧化膜的耐蚀性、     

印刷电解法制备具有可控微纳结构的防结霜铜金属功能表面

目的提出一种在金属表面制备可控的微纳结构的方法,改善金属表面的疏水性。方法利用丝网印刷快速制备可控微细图案,电解加工快速加工出微细结构,化学氧化法制备出纳米结构,从而成功地在铜表面制备了具有微米纳米复合结构的超疏水表面。在此过程中,首先通过丝网印刷辅助电解加工制备有序微圆柱阵列,然后利用化学氧化在微圆柱表面制备纳米结构,通过扫描电子显微镜(SEM)和接触角来表征铜表面的超疏水性能,用质量变化法研究了铜表面的抗结霜性能。结果丝网印刷的圆形掩膜直径为140~160μm,电解加工后,圆柱直径为130~140μm,高度为15μm左右。SEM测试结果表明,用15wt%FeCl_3溶液进行蚀刻,在铜表面出现了圆柱阵列的微纳复合结构。用氟硅烷乙醇溶液改性微纳复合结构圆柱阵列铜表面时,最大接触角为155°,表现出超疏水性能。抗结霜测试表明,所测试的超疏水表面的抗结霜性能显著增强。结论印刷电解法可以制备出形状和尺寸可控的微结构,对微结构进一步处理可得到微纳复合结构。该结构可以构成超疏水表面,且具有抗结霜性能。     

微细阵列结构电子束加工试验研究

基于电子束曝光基本理论和工艺原理,以涂覆有PMMA抗蚀剂的石英玻璃为研究对象,采用电子束曝光制备微细阵列结构,研究不同工艺参数对曝光微细阵列孔和阵列槽结构的影响.结果表明,在PMMA薄膜厚度250 nm、曝光剂量400 pAs/cm2、显影时间120 s的条件下,可制备出直径2μm的阵列微孔结构;在PMMA薄膜厚度22...     

固态纳米孔高能束制造方法

固态纳米孔因具有机械性能好、稳定性强、形状易控的优点,在基因检测、蛋白质检测、能量转换、物质分离以及水净化等领域显示出巨大的潜力,并引起众多研究人员关注。其中,形状可控、高效的固态纳米孔制造技术是现实固态纳米孔应用的前提。目前,在常见的固态纳米孔制造方法中,高能束制造方法具有高效率、高精度、高可控制造的优势。本文重点概述高能电子束、聚焦离子束、激光刻蚀法和离子径迹刻蚀法等4种固态纳米孔制造方法及其基本原理,并讨论上述方法的优缺点及其大规模可控制造的可行性。     

可控合成一维金银合金多孔纳米结构(英文)

报道了一种基于纳米晶体生长及表面修饰技术制备一维金银合金多孔纳米管的合成方法。实验采用多元醇热反应制备多种直径的银纳米线为前驱物模板,通过调控银线尺寸、表面修饰、热扩散、脱合金工艺等实验参数获得结构可控的一维金银多孔纳米结构。运用多种测试方法观察了无孔纳米管、多孔纳米管、多孔纳米线等多种一维结构的孔分布及连续结构。     

倾斜生长法制备表面增强拉曼散射基底及其应用

基于贵金属纳米结构表面增强拉曼散射可实现物质的痕量检测。主要介绍了基于倾斜生长法对Ag纳米棒阵列的可控制备,及其应用于痕量物质的检测,并通过主成分分析法和偏最小二乘回归法建立了痕量物质的半定量和定量分析。     

钛合金阳极氧化法制备自组装纳米多孔结构薄膜

钛及钛合金在含有F-离子的电解液中阳极氧化,可自组装制备出有序TiO2纳米多孔或纳米管阵列薄膜,这类纳米阵列膜材料具有极大的内比表面积和优异的电子传输性能,可以用作纳米结构制备模板、高灵敏度传感器、染料敏化太阳能电池等。以TLM钛合金为阳极氧化的基片,通过改变阳极氧化电压、钛合金相结构,找到了制备纳米多孔阵列的参数,通过条件试验发现,在恒电压小于30V时,经时效处理的TLM钛合金表面可以制备得到合金元素掺杂的TiO2纳米多孔结构薄膜。     

一维钨纳米结构阵列的可控制备

采用金属催化法结合化学气相沉积法制备一维W纳米结构阵列,对一维W纳米结构阵列可控制备进行系统的研究。结果表明:一维W纳米结构阵列的直径主要受到催化剂和N_2流量的影响,随着催化剂颗粒尺寸的减小或者N_2流量的减小,催化生长后W纳米线直径的尺寸也相应变小;一维W纳米结构阵列的长度主要受到生长时间的影响,生长时间的延长会使W纳米线阵列的长度也相应的增加,有利于超长W纳米线阵列的合成;一维W纳米结构阵列的密度主要受到催化剂和WO_3粉末粒径的影响,随着催化剂颗粒的密度的增加或者WO_3粒径的减小,W纳米线阵列的密度也相应增加;一维W纳米结构阵列的形貌主要受到生长温度和基片材料的影响。     

激光蒸凝法制备不同形貌的锌纳米晶

以锌粒或醋酸锌为靶材,以单模100 W CW CO2激光器为光源,采用激光蒸凝法在氢气气氛下制备出不同形貌的锌纳米晶.研究了反应参数对纳米晶形貌的影响,并用X射线衍射、透射电镜、电子衍射和EDTA滴定分析技术对纳米晶的性质进行表征,同时对纳米晶的形成机理进行了探讨.实验结果表明,靶材的种类、反应压力、反应气体的流量等因素对纳米晶的粒度和晶型等性能均有影响.通过改变实验参数,可以得到不同性质的锌纳米晶,从而实现锌纳米晶的可控制备.     

水热法制备高定向掺铝氧化锌纳米棒阵列

为了制备高定向光电性能优异的掺铝氧化锌(ZAO)纳米棒阵列,采用溶胶-凝胶法在玻璃基片上制备掺铝氧化锌薄膜,以ZAO薄膜为种子层,通过控制掺铝量、稳定荆等工艺参数,采用水热法制备出了高定向ZAO纳米棒阵列.实验表明,铝掺杂量为2%,直径在50nm左右的ZAO纳米棒阵列薄膜具有最好的光致发光性能,表面活性剂可以促进ZAO纳米结构的棒状生长,形成高定向ZAO纳米棒阵列.     

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.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

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.