电感耦合等离子体质谱法测定高纯钨中26种痕量杂质元素

采用电感耦合等离子体质谱法(ICP-MS)测定高纯钨中26种痕量杂质元素,讨论了溶样方式,研究了质谱干扰和钨基体效应,应用屏蔽炬技术消除56Ar O+等多原子离子对Fe、Ca、K等元素的干扰,采用在线样品标准加入法消除基体效应。各元素的方法检出限(15σ)为0.03⁰.45μg/g,对样品加标0.5μg/g的回收率在88%0.45μg/g,对样品加标0.5μg/g的回收率在88%¹16%之间。方法适用于纯度为99.999%的高纯钨中痕量杂质元素的测定。     

AAS法测定纯铼中痕量元素K试验研究

用AAS法测定纯铼中的痕量元素K。通过优化原子吸收测量条件,研究了硝酸用量以及基体铼对测定K含量的影响,建立了AAS法测定纯铼中痕量元素K的分析方法。结果表明,AAS法测量K的相对标准偏差不大于9.04%,测定范围为0.000 1%~0.001%,方法检出限为0.003 5μg/m L。本检测方法不仅准确可靠,而且简便快速。     

乙酸乙酯萃取-ICP-MS测定高纯金中杂质元素含量

采用乙酸乙酯萃取分离金基体,用电感耦合等离子体质谱(ICP-MS)内标法测定高纯金中31种杂质元素。萃取酸度为1 mol/L HCl,用25 mL乙酸乙酯可去除金基体对待测元素的干扰,对金的萃取率大于99.9%。将31种元素用~(45)Sc、~(133)Cs、~(159)Tb、~(187)Re等4个内标元素分组测定。方法检出限为0.25μg/L,定量限为0.83μg/L,精密度(RSD,n=12)为0.31%～5.97%,加标回收率为95.3%～109.2%。可满足99.999%的高纯金样品中杂质元素含量的检测。     

ICP-AES测定三氧化钨中硼、铼、钼量

提出了分离基体ICP-AES测定三氧化钨中痕量硼、铼及标准加入法测定三氧化钨中痕量钼的分析方法。研究了基体光谱干扰的情况,选择了最佳分析线,测定了方法检出限,B<0.5μg/g,Re<2.5μg/g,Mo<2.5μg/g。回收率为(95～99)%。     

电感耦合等离子体原子发射光谱法测定铌中磷含量

铌中磷元素的含量高低直接影响铌的性能,关于铌中磷的分析方法,目前普遍采用GB/T15076.7-1994方法《4-甲基-戊酮-[2]萃取分离磷钼蓝分光光度法》。本方法采用硝酸和氢氟酸溶解试样,用电感耦合等离子体原子发射光谱法测定铌中磷含量。实验对元素分析谱线、试剂用量、雾化器流量、泵速、检出限和测定下限进行了研究。应用基体匹配消除基体对待测元素的干扰,工作曲线在磷质量分数0.001 0%～0.080%范围内相关系数为0.999 9,检出限为0.026 2μg/mL,测定下限为8.9μg/g,方法加标回收率在93.00%～108.0%之间,相对标准偏差(RSD,n=11)≤7.20%,分析结果同GB/T15076.7-1994方法进行了对照,结果一致。     

电感耦合等离子体原子发射光谱法测定硼钢铸件中的钆

钆对高质量硼钢屏蔽铸件研究有重要意义。试验采用王水和硫磷混酸分解样品,选择分析线Gd376.839 nm,使用电感耦合等离子体原子发射光谱法(ICP-AES)建立了硼钢铸件中钆的测定方法。仪器的工作条件为:发生器功率1.2 kW、冷却气流量20 L/min、辅助气流量0.1 L/min、雾化器压力36PSI、蠕动泵泵速1.40 mL/min。钆质量浓度在0.5～5.0μg/mL范围内与发射强度呈线性,相关系数大于0.999 9,方法检出限为0.024μg/mL。按照试验方法测定三种硼钢材料中的钆,结果相对标准偏差(RSD,n=11)为1.28%～1.52%,加标回收率为95.0%～106.5%。     

电感耦合等离子体原子发射光谱法测定羰基镍粉中16种杂质元素量

建立电感耦合等离子体原子发射光谱法测定羰基镍粉中砷、镉、铅、锌、锑、铋、锡、钴、铜、锰、镁、铝、铁、钙、钼、硅等杂质元素含量的方法。采用硝酸（3+2）溶解样品，考察了酸度对测定的影响，确定了各元素最佳的分析谱线。在标准溶液中，元素含量分别为0、0.025、0.1、0.5、1.0μg/mL时，十六种元素的强度与浓度呈现良好的线性关系，对应的相关系数均大于0.999。最终的加标回收率为94.0%～104.0%，相对标准偏差RSD<6.53%(n=7)。该方法有效的提升了羰基镍粉中多元素分析的效率，满足硬质合金生产工艺的要求。     

原子吸收法测定化合物三氯化钌中的钠

在5%盐酸介质中,采用原子吸收分光光度计测量三氯化钌中的钠含量。波长选择589.0 nm,钠标准工作曲线范围为0～2.0μg/mL,线性相关系数为0.9999。研究了酸介质、仪器工作条件、基体、干扰元素等因素对测量结果的影响。方法的加标回收率为94.7%～101.5%,不确定度为0.0082μg/mL,检出限为0.001μg/mL。     

电感耦合等离子体质谱法测定高纯铼酸铵中19种痕量杂质元素

本文采用电感耦合等离子体质谱法（ICP—MS）测定高纯铼酸铵中19种痕量杂质元素，应用屏蔽炬技术消除了^56ArO^＋等多原子离子对Fe、Ca、K等元素的干扰，讨论了质谱干扰和锥的接口效应，优化采样时间，研究了铼酸铵的基体效应，采用在线样品标准加入法消除基体效应。各元素的方法定量下限（15σ）为0．014-0．63μg／g，对样品加标0．4μg，g的回收率在85％～112％之间。方法适用于纯度为99．999％的高纯铼酸铵中痕量杂质元素的测定。     

ICP-AES测定纯金饰品中的痕量钯及其不确定度评估

建立了王水溶解纯金样品、标准基体匹配、电感耦合等离子体发射光谱(ICP-AES)测定纯金饰品中痕量钯元素的定量分析方法。该方法具有简便、快速、灵敏度高、重现性好等优点。方法检出限为0.08μg/g,加标回收率为104%,相对标准偏差(RSD)为7.52%,A类不确定度为0.0119 mg/L。     

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。