基于Moldflow仿真分析的格栅注射模设计

基于Moldflow分析软件对空调风机管盘的中盖格栅塑件进行模流仿真分析,结合塑件成型要求及特点,设计了5种浇注方案。通过分析对比不同浇注方案的结果,选择最优的浇注方案并设计模具结构。模具经生产实际证明：降低了成型塑件抱紧力、易粘模具零件的风险,保证模具顺畅、高效的生产。     

瓶盖二次顶出模具设计

根据塑件的结构特点,设计二次顶出机构注塑模具。模具开模后,在顶出结构的推动下,模具的顶杆和型套共同作用,分二次顶出塑件,分散了脱模力对塑件的影响,保证了塑件的质量。     

某汽车零件注塑模设计及成形过程CAE分析

在综合考虑某塑件成形工艺特点的基础上,确定该塑件的模具结构方案,设计注塑模具,并在理论设计基础上绘制模具装配图,分析模具工作原理,然后通过三维造型软件对模具进行实体造型,最后利用Moldflow软件对塑件进行成形性能分析。     

侧滑块和滑块侧抽芯注塑模设计

针对单侧分布有侧孔、表面有浅槽和薄壁复杂塑件难成型的问题,进行了该塑件的注塑模设计研究.通过对塑件的结构和成型工艺性分析,利用侧滑块带动滑块作纵向、横向滑动,设计了侧滑块和滑块侧抽芯的注塑模具结构,实现了模具结构中的侧向分型.结果表明:该套模具结构紧凑,侧抽芯机构的运动平稳可靠.     

薄板塑件成形熔体Moldflow流动模拟分析

以成型薄板塑件的2种熔体流动方案分析为例,简要介绍MPI的作用,通过应用MPI软件对2种成型方案进行熔体型腔填充时间、塑件变形与熔接痕对比分析,最终得到一套切实可行的方案,减少了模具开发周期和费用,提高了塑件生产效率和质量。     

花洒底座注射模设计

通过对花洒底座塑件结构的结构特点、使用性能的分析,设计出合理的模具结构方案,本文采用一种特别的定模抽芯机构,文中说明了模具的工作过程,经生产验证,模具结构合理、生产顺畅,并能达到塑件质量要求.对设计生产类似的塑件有一定的参考作用.     

8齿头线卡的注塑模设计

通过对一款汽车线束用8齿头线卡塑件的成型特点和要点进行分析,介绍了塑件型腔分布、成型分型面的选择及浇注系统的设计,阐述了精密注塑模具的精确定位设计方法和两面顶出的设计技巧,以及模具的结构和关键部件的加工工艺等,保证了产品的质量。结果表明,该设计提高了塑件的精度,能满足大批量生产的需求,是一套安全、可靠和实用的模具。     

RJ45网线水晶头注射模设计

针对具有金属嵌件网线水晶头塑件结构特点,通过方案分析比较,确定了生产该类制件的2次分型模具的结构方案,重点分析塑件左侧凹槽的实现和金属嵌件的固定这2个难点。采用斜导柱外侧抽芯机构来实现左侧凹槽抽芯,顶杆顶出机构来实现金属嵌件的固定。采用Pro/E、AutoCAD软件进行塑料注射模辅助设计,模具总体上采用1模8腔,采用外侧潜伏式浇口既可保证塑件的表面光滑度又可实现浇注系统与塑件的自动脱离,大大提高了模具的工作效率。所设计的模具结构合理,生产效率高,是一副实用性较强的模具。     

隧道式浇口凝料自动切断机构设计

介绍一种优化的隧道式浇口形式,通过设计3组推出机构和2套组合拉钩机构,完成塑件与凝料的二次推出,实现模具浇口自动断料及自动化生产,并详细阐述该组合机构的结构组成及工作原理,对类似模具结构提供设计参考。     

从成型工艺谈提高塑件的结构工艺性

塑件结构不合理,会造成模具制造困难和塑件成型困难,模具设计人员应对塑件结构提出改进方案,并知会产品设计人员,由其确认。本文主要介绍通过一些经验设计提高塑件结构工艺性的方法。     

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.     

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.