轮架组件注射模设计

介绍了2个配套塑件同模生产需要的三板式模具,模具布局为1模2腔结构,浇口采用点浇口及点浇口+侧浇口,设计了5个抽芯机构实现塑件的自动脱模,针对内壁圆环凹槽运用中央驱动块驱动双侧成型滑块内收抽芯实现脱模,利用成型滑块延时差动抽芯避免塑件因抽芯脱模距离大而产生脱模时塑件变形。经实际生产验证:模具结构合理,机构设置巧妙,具有一定的参考作用。     

手机面盖注射模设计

介绍了某手机面盖注射模结构与工作过程,模具采用热流道浇注系统,设有3个侧向滑块抽芯机构,一个侧向内螺纹自动脱模机构以及5根动、定模斜推杆抽芯。各脱模机构工作稳定可靠,生产的塑件质量符合设计要求。     

盒盖注射模设计

分析了盒盖塑件的结构工艺性,确定了合理的两板模结构,依据塑件形状特点确定了斜导柱外抽芯、弹簧内抽芯两种侧抽芯机构。通过两种抽芯机构的对比,最终选择内抽芯的脱模机构,巧妙的利用弹簧动作实现了盒盖塑件脱模需要,模具结构简单、生产效率高,是一种比较新颖的内抽芯模具;对有抽芯机构的注射模设计有一定的参考价值。     

基于定模抽芯的手机前壳注射模设计

介绍了某手机前壳的成型工艺,设计了相应的注射模。在模具中巧妙地设计了定模抽芯机构,解决了塑件脱模难的问题,很好地解决了侧抽芯与塑件脱模的动作顺序。对动模抽芯机构设计、浇注系统设计、主要成型零件设计、冷却系统设计、脱模机构设计等进行了分析和探讨,阐述了模具结构与工作过程。     

多型芯周向抽芯注射模设计

介绍了一种周向多型芯注射模抽芯机构设计,并以需要周向多型芯抽芯的某款装饰灯灯罩注射模为例,阐述了该抽芯机构的工作原理及模具结构。该设计突破了传统的弯销和滑块组合的思路,利用弹簧巧妙地实现了周向多个型芯的顺利脱模,模具结构简单紧凑,动作可靠。     

铲车气门罩注射模设计

针对铲车气门罩的抽芯脱模需要,定模侧设计了3个直线抽芯滑块用于水平侧孔的脱模和1个斜向抽芯滑块用于斜孔的脱模,动模侧使用了5个斜顶机构用于倒扣的脱模和1个斜向抽芯滑块用于斜孔的脱模。斜抽芯机构和水平抽芯机构使用T形槽锁紧块进行开模方向的直线型驱动,能有效简化模具结构,节省模架空间,减少模具制造成本。     

洗发水瓶盖注射模设计

介绍了1副洗发水瓶盖注射模,模具的动模采用外螺纹自动脱模机构和圆弧侧向抽芯机构,外螺纹自动脱模机构动力来源于液压缸,圆弧侧向抽芯机构不需要任何外部动力。模具结构简单,设计新颖,可供同行借鉴。     

水室注射模设计

分析了水室的结构和注射成型存在的工艺问题,选择了成型工艺参数,确定了注射模结构为1模2腔。在模具中设计了细长侧抽芯脱模机构、顺序动作侧抽芯机构、推出机构。结果表明:顺序脱模侧抽芯机构可解决水室塑件凸起部分形成倒钩的脱模问题。     

注塑机气枪手柄注射模设计

设计了1副1模2腔、2次开模的两板模成型注塑机气枪手柄,针对塑件薄壁特点,使用流动性好并添加增流剂的PC料进行成型。在料流末端增设冷料穴保证型腔充分填充;设计了5种脱模机构进行脱模,分别为斜孔定模锁紧块滑块斜抽芯机构、倒扣孔定模推板斜推机构、定模液压缸抽芯机构、连杆式弯管抽芯机构及推杆推出脱模机构。脱模机构中,连杆式弯管抽芯机构在定、动模分型面打开时,通过驱动连杆驱动弯管型芯抽芯的结构方式,避免复杂弯管抽芯驱动机构的设计,有利于简化模具结构和降低模具制造成本。     

螺帽自动脱模机构注射模具设计

介绍了一种螺帽注射模具的脱螺纹抽芯机构及其模具设计。针对有内螺纹的螺帽塑件,设计了一种定模转动的自动脱模机构。该机构采用液压马达带动链条,链轮驱动花键轴使螺纹镶件转动抽芯,从而实现内螺纹产品自动脱模。该抽芯机构结构新颖,模具结构设计合理,工作稳定可靠。     

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).     

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.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.