压簧簧片工艺分析与级进模设计

分析了压簧簧片的成形工艺,确定了冲压工艺方案,设计了7个工位的级进模,采用弹压卸料板及压杆将条料稳定在各工位上,保证条料在各工位间传递的平稳性和可靠性,模具制造成本低,能满足稳定、高效生产的要求。     

继电器簧片多工位级进模设计

分析了继电器簧片的结构特点和冲压成形工艺,介绍了簧片多工位级进模排样方案、总体结构和设计要点,重点分析了单元组合式冲裁、弯曲机构的实现方式。     

手柄多工位级进模设计

分析了文件夹手柄多工位级进模的冲压工艺 ,设计了排样图及模具结构。说明了模具结构的特点。该模具的上下模固定板具有高精度和长寿命 ,可快速更换凸模和凹模镶块 ,且重复装配精度高 ,可快速定位导料板 ,卸料板上安装了弯曲上模 ,卸料板既可弹性压料又可刚性卸料。     

手柄多工位级进模设计

分析了文件夹手柄多工位级进模的冲压工艺,设计了排样图及模具结构.说明了模具结构的特点:模具的上下模固定板具有高精度和长寿命,可快速更换凸模和凹模镶块,且重复装配精度高,可快速定位导料板,卸料板上安装了弯曲上模,卸料板既可弹性压料又可刚性卸料.     

接触弹片多工位级进模设计

介绍接触弹片多工位级进模的工艺分析、排样设计、模具结构.该模具采用侧刃定距,导正钉定位,导料板导向,可以同时完成切废料、冲孔、切断、弯曲、落料等工序.用带状条料作为原料,且采用自动送料装置送料.模具可以完全实现自动化大批量生产,极大地降低了劳动强度,提高了生产效率.     

汽车过滤器后支架级进模设计

汽车过滤器后支架零件的形状和结构包含冲切、翻边、压印、弯曲和分离等冲压工艺特征。分析其零件结构、生产批量和冲压工艺性,采用级进模可满足零件生产要求。为保证制件的精度和连续冲压过程,设计了与分离工位角度相同的工艺切口,并在对应工位的模具设计了让位槽,确定了以冲孔、冲切、弯曲和整形为主的排样方案;采用导尺配合导正钉定位,设计了内外导向机构和弹性卸料装置进行压料和卸料以保证产品精度;对设计的模具进行了加工、试冲。结果表明,设计的10工位级进模结构合理,成形的产品符合尺寸和精度要求。     

锁扣的冲裁翻孔弯曲级进模具设计

通过对锁扣冲压工艺性和冲压工艺方案的分析,确定了冲孔、翻孔、切断、弯曲等7个工序3个工位的排样设计。进行了冲压工艺计算,确定了压力中心,选用了合理的弹性元件。弹性卸料装置保证了条料向前送进时能保持平整;采用始用档料销定位,定位简单且可保证精度;凹模采用镶块式,便于更换,降低了模具制造成本。     

正极片冲压工艺分析与多工位级进模具设计

分析了正极片冲压工艺及多工位级进模具设计中的技术难点,重点论述了工位设计、排样图设计、步距精度计算、模具结构设计及关键零件设计等关键技术.为保证条料的同步移动和送料顺畅,模具采用浮动式弯曲下模和浮动导料销;为简化结构、降低成本,采用简化的模架;为避免已成形的工件变形,采用了双斜面的凹模刃口.生产实践证明,工艺方案合理,模具结构安全可靠,达到了技术要求和产量要求.     

上门绞座冲孔弯曲落料级进模设计

介绍了上门铰座冲孔弯曲落料工艺的排样方案、模具结构及设计要点 ,将冲孔、弯曲、落料工位用1副模具完成 ,提高了生产效率     

插座簧片多工位级进模设计

分析了插座簧片零件的冲压工艺,阐述了采用多工位级进模生产的可能性,介绍了冲压件的排样设计、模具结构特点及模具关键零件设计.对同类零件的模具设计有一定的借鉴作用.     

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。