元素扩散对Cr2O3陶瓷薄膜结构和摩擦学性能的影响

目的 通过高温热处理,不同基材会发生不同的组织演变,研究了组织演变对基材中金属元素高温扩散的影响,从而判断其对多弧离子镀制备Cr2O3陶瓷薄膜形貌、结构以及摩擦学性能的影响。方法 利用多弧离子镀技术在不同基材表面(Inconel 718合金、IC10合金、45钢、316不锈钢)沉积Cr2O3薄膜。使用扫描电子显微镜(SEM)和冷场发射扫描电镜(FESEM)分析了基材和薄膜高温退火前后的表面形貌,并且利用EDS分析了基材和薄膜表面的元素含量变化。采用X射线衍射仪(XRD)对Cr2O3薄膜进行物相分析,使用往复摩擦磨损试验仪、三维轮廓仪以及扫描电子显微镜分析了基材和薄膜退火前后的摩擦学性能。结果 热处理后基材中的元素会扩散到其表面,Inconel 718合金、IC10合金和45钢热处理后,其摩擦因数降低。在Inconel 718合金和316不锈钢表面沉积的Cr2O3薄膜高温退火后,基材中的金属元素沿着Cr2O3薄膜晶界扩散至薄膜表面,并与大气中的O2反应形成三元氧化物。Cr2O3薄膜经1 000 ℃退火后,Inconel 718合金中的Ti元素扩散至Cr2O3薄膜表面形成类网状凸起结构,且薄膜表面形成CrTiO3和Cr2O3混合相,316不锈钢中的Mn元素扩散至Cr2O3薄膜表面形成尖晶石结构的MnCr2O4相,45钢表面上沉积的Cr2O3薄膜在850 ℃退火后薄膜表面形成以Fe元素为主的大颗粒,薄膜表面物相为Fe2O3和Cr2O3混合相,IC10合金表面上沉积的Cr2O3薄膜表面没有发现基材中的金属元素,主要物相为Cr2O3相。Cr2O3薄膜退火后摩擦因数降低至0.45左右。结论 Inconel 718合金、45钢以及316不锈钢中的金属元素扩散至薄膜表面时,其对Cr2O3薄膜的物相组成、表面形貌以及摩擦学性能有很大的影响。IC10合金表面上沉积的Cr2O3薄膜热处理后,磨损寿命较低。Inconel 718合金表面上沉积的Cr2O3薄膜具有优异的摩擦学性能。     

马来酸酐等离子体改性聚丙烯薄膜表面的硫酸腐蚀行为

以马来酸酐的等离子体聚合方法对聚丙烯薄膜表面进行了亲水改性,用FT-IR、接触角等分析手段研究了等离子体处理功率对改性薄膜表面的化学结构和亲水性能的影响以及薄膜表面的马来酸酐等离子体聚合物在高温强酸环境中的腐蚀行为.结果表明,马来酸酐等离子体聚合物可水解为聚马来酸结构,改性薄膜表面接触角达到43°～50°,接触角随处理功率的提高呈上升趋势.50W的马来酸酐聚合物的耐110℃、40%硫酸腐蚀性优于30W的马来酸酐聚合物;在高温硫酸介质的腐蚀环境下,马来酸酐的等离子体聚合物可通过磺化反应而引入亲水的磺酸基团,腐蚀后改性薄膜的表面接触角进一步降低至30°以下,获得了更佳的表面亲水性.     

PVDF压电薄膜制作传感器的理论研究

利用PVDF压电薄膜制作传感器是近年来传感器领域的研究新热点。通过对PVDF压电薄膜压电性能的研究，导出PVDF压电薄膜的传感方程，从而为用其制作传感器提供了理论基础，并对偏转角θ进行分析讨论。     

TiN、AIN薄膜的摩擦磨损和抗高温氧化性能及机制

采用电弧离子镀工艺在1Cr18Ni9Ti奥氏体不锈钢表面沉积TiN、AlN薄膜，通过扫描电镜、摩擦磨损试验和高温氧化试验等方法研究了薄膜的微观结构、化学成分与其摩擦性能和抗高温氧化性能之间的关系，同时探讨了薄膜的摩擦磨损机制和高温氧化机制。     

AlN陶瓷表面状态对Ti/Ni金属化薄膜粘结性能的影响

采用电子束蒸发技术在AlN衬底上蒸镀Ti/Ni双层金属化薄膜,通过SEM、EDS和AES等方法分析抛光AlN表面状态及与金属化薄膜间的相互作用.结果表明:离子束清洗可去除AlN衬底表面疏松层,改变AlN衬底表面状态,提高衬底表面能.结合热蒸发原子的作用,膜基界面处Al、N和Ti元素之间产生相互扩散现象,AlN陶瓷和Ti膜的附着机制由未清洗前的简单附着改变为扩散附着,极大提高了金属化薄膜粘结性能,其拉脱强度达300 MPa以上,且无需后续退火处理.     

自蔓延高温渗硼共晶化的研究

初步探讨了自蔓延高温渗硼共晶化的基本原理及具体工艺。结果表明,采用自蔓延高温渗硼共晶化处理可在极短的时间内在工件表面形成一层厚度均匀的共晶组织型渗层,与其它渗硼共晶化方法相比具有节省能源、工艺操作简单的特点,而且无需专门的加热设备,尤其适用于大型工件的局部处理。     

磁控溅射SiC薄膜表面形貌演化行为研究

采用射频磁控溅射法在石英玻璃基底上沉积SiC薄膜.用扫描电子显微镜(SEM)和原子力显微镜( AFM)观察薄膜的表面形貌,利用粗糙度和颗粒度大小对薄膜表面形貌动态演化进行量化表征.结果表明:在100～175 W溅射功率范围内,1 000℃高温真空退火处理能明显减小SiC薄膜表面粗糙度,膜层表面更为平滑,颗粒大小更为均匀...     

A1含量对（Ti，A1）N薄膜抗氧化性能的影响

研究了Ａ１含量对（Ｔｉ，Ａ１）Ｎ薄膜高温抗氧化性能的影响，并与ＴｉＮ薄膜进行了对比试验．试验结果表明：（Ｔｉ，ＡＩ）Ｎ薄膜的抗氧化性能明显优于ＴｉＮ薄膜；随着薄膜中Ａ１含量的增加，薄膜的抗氧化能力得到改善，特别是当氧化温度≥８００℃后效果更为显著．这是因为（Ｔｉ，Ａ１）Ｎ薄膜在高温下氧化时，在薄膜表面形成的是稳定致密的Ａ１２Ｏ３的缘故．     

Al含量对（Ti,Al）N薄膜抗氧化性能的影响

研究了Ａｌ含量对（Ｔｉ，Ａｌ）Ｎ薄膜高温抗氧化性能的影响，并与ＴｉＮ薄膜进行了对比试验，试验结果表明：（Ｔｉ，Ａｌ）Ｎ薄膜的抗氧化性能明显优于ＴｉＮ薄膜，随着薄膜中Ａｌ含量的增加，薄膜的抗氧化能力得到改善，特别是当氧化温度≥８００℃后效果更为显著，因为（Ｔｉ，Ａｌ）Ｎ薄膜在高温下氧化时，在薄膜表面形成的是稳定致密的Ａｌ２Ｏ３的缘故。     

高温氧化薄膜中残余应力分析和试验方法

介绍一种高温氧化薄膜应力的测定技术，在一定高温氧化条件下能测定氧化膜中的生长应力，在某一温度变化范围内能测定氧化膜中的热应力，这种技术可在普通衍射仪上进行。     

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。