等温热成形钛合金零件尺寸精确控制方法

为了研究等温热成形钛合金零件尺寸的精确控制方法，分析了钛合金零件等温热成形过程，确定了影响零件尺寸的主要因素为热膨胀、回弹及切割变形，并研究了其影响机理及控制措施。以某钛合金零件为例，仿真分析了其热膨胀和回弹变形，基于热膨胀和回弹机理，提出了热膨胀和回弹补偿量方法及计算公式，并进行了实验验证。结果表明，成形后零件与设计基本一致，证明热膨胀和回弹补偿方法可行。通过对热膨胀和回弹的精确补偿，有效提高了零件精度，提高了调试效率，实现了精确控制等温热成形钛合金零件尺寸。     

铝合金支架间接挤压铸造的研究

基于有限差分法，对大型铝合金支架间接挤压铸造充型和凝固过程进行了数值模拟。通过对模拟结果的分析，确定了浇注温度为700℃，压射速度为0．03m／s，完成了模具结构和工艺设计，并制作了模具，进行了支架挤压铸造的试制。分析了试制过程铸件缺陷产生的原因，发现气孔和氧化夹渣等是主要缺陷，通过调整脱模剂的配方，适当减少脱模剂的喷涂，缩短挤压铸造循环时间等，获得了品质和性能良好的支架铸件。     

在结构调整中加快上钢的发展步伐

分析了上钢系统发展的基本情况，面临的各种挑战与机遇，提出了上钢结构调整的目标，方向和原则，并探索产品，工艺技术，资本，企业组织和人力资源等关键要素，在组合形式，时空排序和比例关系，及有效提高系统整体功能等方面，提出了自己的见解和建议。     

第二届国际淬火和变形控制会议论文综述

本文综述了第二届国际淬火和变形控制会议的论文，着重就冷却曲线分析，淬透性预测，淬火方法和变形，显微组织和过程模拟，气淬及水汽和喷射淬火等专题作了评述，反映了淬火冷却技术的国际最新研究和发展趋势。     

SDH13钢的组织性能及热疲劳行为研究

研究了钢的生产工艺对模具性能和使用寿命的影响。研究结果表明，普通工艺生产的H13钢模块含有大块状共晶碳化物，并且存在成分偏析，导致钢的冲击韧度降低，影响模具的使用性能。而采用高温均匀化和超细化等工艺处理SDH13钢，则消除了大块共晶碳化物，改善了偏析和碳化物的形态及分布，细化了组织，从而提高了模块的心部强韧性和模具的使用寿命。     

硅弧焊整流器闭环控制的研究

对常用的手弧焊磁放大器电源进行了分析和研究，建立了该系统的数学模型，设计了闭环控制系统，阐述了根据自控理论设计调节器的原理和方法，给出了计算机相联的接口电路，试验表明：该系统不仅实现了恒流控制，使焊接规范稳定，而且其动特性和调节特性大为改善。     

预时效处理对AlZnMgCu铝合金自然时效和烘烤硬化行为的影响

研究了一种AlZnMgCu铝合金的自然时效行为，利用预时效处理降低自然时效过程的硬化效果，提升人工时效过程的硬化效应。利用金相显微镜和透射电镜表征了微观组织结构，测试了显微硬度和拉伸性能。结果表明，预时效处理提高了AlZnMgCu铝合金的初始硬度，但经历12天的自然时效后，最终硬度反而小于固溶后直接自然时效的硬度，降低了24%(120℃预时效);预时效处理后的试样，经自然时效和180℃×20 min的人工时效处理后，屈服强度和抗拉强度分别增大了165 MPa和48 MPa,提高了55.9%和11.2%。固溶+自然时效处理后，基体内GP区尺寸大小不一，分布不均，而经预时效处理后，GP区尺寸和分布均匀，与α-Al基体呈共格关系；预时效+自然时效+人工时效后，η′相粒子尺寸均匀且弥散分布，与α-Al基体呈半共格关系，起到了明显的时效硬化作用。     

镁合金的塑性加工技术

分析了镁合金的塑性变形特点及应用前景，阐述了镁合金塑性加工研究现状及在材料，性能和加工制造方面的发展方向，分析了镁合金挤压，锻造，冲压，胀形等变形特点及工艺关键。讨论了镁合金的各种加工性能和环境影响，总结了镁合金塑性加工技术的最新进展。     

铝冶炼用LLZB袋式除尘器流化床面积的探讨

本文对LLZB的流化床进行了全面、客观和系统的分析及计算，论述了减小流化床面积的可行性，可实施性和可靠性。从理论上阐明了LLZB流化床面积的计算，将LLZB流化床面积由15．8m^2减小到2．15m^2，减小了86％，使流化风系统的投资和运行费用明显降低。通过对清灰制度的改进，一方面保证了LLZB运行的安全性，另一方面增强了整个净化设施运行的稳定性，使净化设施的操作和维护更加方便。     

钛、氮离子注入改善人造金刚石性能的试验研究

金刚石固有的缺陷，如裂纹和磁性包裹体的存在降低了其力学性能和热稳定性，也使金刚石工具的使用性能降低。本文利用离子束注入技术，对金刚石表面同时注入钛、氮离子来改善人造金刚石的性能进行了试验研究。测量了经离子注入处理的金刚石的抗压强度和热稳定性，以及孕镶金刚石复合材料的抗弯强度和磨耗比。试验结果表明：钛、氮离子注入后，填补了金刚石晶体表面的缺陷，从而提高了金刚石的抗压强度和热稳定性，其抗压强度提高了6～34％，热失重率降低了20％。此外，和离子注入前相比，用离子注入后的金刚石烧结的复合材料的抗弯强度和磨耗比也有了较大幅度的提高。     

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.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

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).     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

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.