直驱式打击液压阀及其控制的研究

打击液压阀控制着数控全液压模锻锤的主要动作，其动态性能的好坏也就直接影响着模锻锤的工作性能。通过用SimulationX软件来仿真分析数控全液压模锻锤的液压系统，得到模锻锤的工作性能曲线和相关参数，与实际情况进行比对，进而得出打击液压阀的工作参数，为打击液压阀的结构设计和优化打下了基础。     

液压模锻锤液压控制系统研究

阐述了液压模锻锤的结构及工作原理。通过动量定理建立了全液压模锻锤液压缸的数学模型,为设定打击能量和打击次数的大小提供了依据,同时为实现模锻锤运行过程的精确控制提供了理论参考。并对锤头速度、位移、动能变化情况进行了试验仿真,通过仿真分析为其进一步实现模锻锤打击工序和打击能量的数控化和柔性化奠定了基础。     

数控全液压模锻锤的能量控制与仿真

在对63 kJ数控全液压模锻锤系统分析的基础上,提出通过建立数学模型,并应用Simulink进行仿真分析,从而直观地求出打击阀的开启时间t与打击能量e之间的能量仿真关系,实现比较精确的能量控制.通过对打击阀的开启时间t与打击能量e之间的仿真结果分析,为数控全液压的反馈控制提供了参考,该方法目前已在模锻锤开环控制方面取得...     

精密模锻锤的特点及应用

本文介绍了数控全液压模锻锤、“X”导轨型液气式电液模锻锤的性能和结构特点，阐明了精密模锻锤是理想的精锻设备。     

中机锻压缸阀一体程控全液压模锻锤研制成功

正由中机锻压江苏股份有限公司自主研发、设计、生产的具有自主知识产权的缸阀一体程控全液压模锻锤研制成功。缸阀一体化技术克服了现有程控锻锤技术的缺点,有效地提高了锻锤打击能量控制精度、锻锤可靠性及能源利用率。缸阀一体程控全液压模锻锤技术是将独特的筒式结构锥阀(打击阀)同轴安装于工作缸顶部,实现缸阀一体化,其优势     

智能型全液压模锻锤技术评价会

智能型全液压模锻锤技术评价会于 2 0 0 2年 1 0月 1 6日在江苏海安召开 ,与会代表有来自清华大学、上海交通大学等 9个科研所 2 0余位专家、学者。与会代表认真听取海安百协锻锤有限公司张长龙总工程师关于智能型全液压模锻锤技术介绍。该锤充分发挥了传统锻锤灵活自如、成形速度快的优势 ,综合运用了在线传感、数字显示、智能监测控制等现代电子技术 ,实现打击能量、打击步序的自动控制、故障的自动诊断显示 ;采用了全液压模锻锤专利技术、高度集成的锥阀控制技术 ,实现模锻锤高效、节能、高可靠的全液压动力驱动 ;采用整体Ｕ形铸钢砧座床…     

全球最大程控锻锤在中国重汽顺利投产

正2018年12月26日,由中机锻压江苏股份有限公司研制的全球最大的450kJ程控全液压模锻锤在中国重汽顺利投产。450kJ程控全液压模锻锤应用中机独有的缸阀一体控制技术、液压系统集成技术、液压油安全防漏技术、打击能量的数字化控制技术、直接隔振技术,实现了大型程控锻锤打击能量的精确控制与高可靠运行,实现了在工作状态下磕锤、压锤、短行程连续打击动作的任意切换与数字控制。     

基于FM352的数控模锻锤速度位置测量系统

为解决数控模锻锤对于实际打击能量和实际打击厚度不能精确反馈的问题,开发了基于FM352的速度位置测量系统。该系统通过精确测量数控模锻锤的锤头运动速度和运动位置,从而实现检测锻锤上锻件的实际打击能量和实际打击厚度的目的,对于提高锻件锻造精度具有重要的实际意义。     

CTK-320程控全液压有砧锻锤顺利投产

由江苏海安百协锻锤有限公司承制的具有国际先进水平的CTK-320程控全液压模锻锤,于日前在青海康泰锻造有限责任公司(原青海东风模锻)一次试车成功并顺利投入三班连续生产。CTK-320程控全液压模锻锤,打击能量为320 kJ(相当于13 t锤)。     

CTK-320程控全液压有砧锻锤顺利投产

由江苏海安百协锻锤有限公司承制的具有国际先进水平的CTK-320程控全液压模锻锤,于日前在青海康泰锻造有限责任公司(原青海东风模锻)一次试车成功并顺利投入三班连续生产。CTK-320程控全液压模锻锤,打击能量为320 kJ(相当于13 t锤)。     

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.     

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。     

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.     

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.     

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).     

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.