直接光谱法测定TC4钛合金中杂质元素

本文采用载体分馏直接光谱法,以氯化银和碳粉混合物作载体,通过直流电弧,阳极激发,在一个谱板上一次完成合金中11个杂质元素的分析。测定灵敏度一般为5×10~(-5)%—1×10~(-3)%,单次测定均方偏差为±8%—±19%。     

增塑挤压簿壁多孔钛管

宝鸡有色金属研究所第四研究室用增塑挤压法研制成了多孔簿壁钛管。增塑剂为甲基纤维素,润滑剂为硬脂酸。已制成ф5×0.5×400、ф10×1×400、ф20×1×400毫米等多种规格的簿壁多孔钛管,其最大孔径为5—15、15—25和30—50微米,相对透气度分别为0.5—1×10~(-4)、1—3×10~(-3)和3～6×10~(-3)升/厘米~2·分·毫米汞柱。此种增     

NdB4和Nd2FeB3标准生成自由能的测定

用CaF_2单晶为固体电解质构成原电池,在996—1061K测定了电池的可逆电动势,求得了NdB_4和Nd_2FeB_3的标准生成自由能为: △G°_(NdB_4)=(-838.5+4.1×10~(-1)T)×10~3Jmol~(-1) △G°_(Nd_2FeB_3)=(-1019.9+4.6×10~(-1)T)×10~3Jmol~(-1)     

钛及钛合金中微量稀土元素光谱测定

本文采用发射光谱载体分馏法,测定了钛及钛合金中Er、Y、La、Gd、Dy、Ce等六个微量元素,对载体、缓冲剂、电极形状、电流强度、曝光时间的选择进行了研究。本方法快速、简便,灵敏度为3×10~(-3)—1×10~(-1)%,相对标准偏差为8.3—19.9%,回收率为82—130%,能满足科研和生产的要求。     

铸造有色金属及合金中微量硼的测定

在强酸非水介质中硼酸与姜黄素结合生成有色物质,加入适量的乙酸丁酯脱水,并用乙酸铵缓冲溶液消除姜黄素的干扰,测量其吸光度以达到测定微量硼之目的,确定了铸造有色金属及合金中微量硼测定方法。检出限为：7.7×10-5μg/mL,相对标准偏差为0.59%（3.3×10^-4μg/mL,4J497044,n=10）,线性范围为：2.0×10^-4-1.2×10^-3μg/mL。准确度和稳定性都较好,方法简便、快捷。     

高纯钛中痕量杂质的化学光谱测定

取高纯钛1克,用氢氟酸溶解后,加盐酸在水浴上蒸发到小体积,在酒石酸铵存在下,用吡咯烷二硫代氨基甲酸盐-双硫腙/三氯甲烷在pH值为3、5、7的条件下萃取,使杂质与主体分离并得到富集。将有机相蒸干,破坏有机物质,将残渣进行光谱测定。本方法可以测定高纯钛中As、Co、Cd、Sb、Fe、Mn、Pb、Cr、Sn、Ni、Bi、V、Mo、Cu、Zn等15个元素,测定下限为1×10~(-5)—5×10~(-5)%。     

统一标样磁性法测量GCr15钢残余奥氏体量的尝试

本研究首先摸索了磁性法测残余奥氏体所需的标样处理工艺 ,认为GCr15钢经10 5 0℃淬火 ,-78℃× 1.5h深冷处理 ,2 80℃× 2 0min回火可得到全马氏体组织。用该标样测定不同工艺处理GCr15钢的残余奥氏体量 ,虽然各工艺的淬火温度不同 ,但经 >15 0℃回火后 ,回火马氏体的碳含量将趋于一致。经 85 0℃淬火 ,180℃、2 0 0℃、2 3 0℃、2 60℃、2 80℃分别回火 10min、2 0min、3 0min后GCr15钢组织中残余奥氏体含量的变化趋势与资料曲线相吻合。经 85 0℃淬火 ,2 0 0℃× 2 0min回火后 ,钢中残余奥氏体量为 10 %左右 ,满足使用要求。统一标样磁性法已被实践证明简便可行。     

ZL-115合金的热处理工艺探讨

通过对 ZL - 115合金数种不同工艺热处理后的力学性能的研究 ,确定出较好的热处理工艺为 :　　固溶 :5 2 0 ± 5℃× 2 h+5 30 ± 5℃× 10 h+5 4 0 ± 5℃× 4 h,水淬 (水温≥ 6 0℃ )　　时效 :(80～ 10 0 ) ± 3℃× 10 h+15 0 ± 3℃× 4 h,空冷     

镁的精炼、高纯镁的制取、镁及其合金制品和半成品的生产

工业制取的镁平均含有,％:Fe 0.03;Si 0.002;Al 0.01;Ni 0.0005;Cu 0.002;Mn 0.01;Cl 0.003;Zn 0.005;Pb 0.002;Ca 0.002;Cr(0.5～1.3)×10~(-4);Ti(1～8)×10~(-4);Sb(7～9)×10~(-6);Cd(0.5～1.2)×10~(-5);P(1～4)×10~(-3);As(1.5～3.0)×10~(-4);N(0.5～2)×10~(-3);C(1～4)×10~(-3);O(2～4)×10~(-2);以及Bi、Cs、Co各约10~(-3);Sn和Rb各为5×10~(-4);Sn、Ba、Mo、Ag、Sr、W各为1×10~(-4);Hf2×10~(-4)。镁中金属夹杂物主要来源于盐类原料、炉衬和电极材料。大气中的氧、氢和氮也会进入     

Zr5Si3及Zr3Ti2Si3弹性性质与热学性质

应用基于密度泛函理论的平面波赝势方法计算16H金属硅化物Zr5Si3及Zr3Ti2Si3的基态晶格参数,得出弹性常数、体弹性模量、弹性模量、剪切模量及泊松比等弹性性质.利用弹性常数计算德拜温度、格林奈森常数,并在德拜-格林奈森模型基础上计算这两种金属硅化物的各向异性热膨胀系数,由此得出Zr5Si3的a、c方向各向异性热膨胀系数(高温时)分别为8×10-6和15×10-6,对Zr3Ti2Si3(高温时)分别为11×10-6和13×10-6,与实验基本相符.根据方向体弹性模量、方向弹性模量及重叠布居数讨论两种材料各向异性热膨胀不同的原因.     

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。