收音机后盖注射模设计

分析了收音机后盖的侧凸和侧孔结构,设计了斜推杆内侧抽芯机构和斜导柱外侧抽芯机构,完成了制品侧向结构的抽芯。对斜导柱滑块头部结构进行了优化设计,简化了模具结构。实践证明,模具结构合理,成型的制品质量合格。     

阀门试验用螺纹密封件模具设计

根据螺纹密封件的结构特点及功能要求,设计了一副低温真空绝热截止阀试验所使用的侧向抽芯结构塑料模具。模具采用了一模二腔的平衡式型腔分布、矩形侧浇口进料的浇注系统、斜导柱侧向抽芯,合理设计了由整体嵌入式凹模、整体式凸模、侧螺纹型环滑块组成的成型零部件、导向机构、推出机构、冷却系统等模具结构,阐述了模具的动作过程。该设计简化了模具结构,提高了生产效率。     

温控器固定架注塑模设计

根据温控器固定架产品结构的特点,选择分型面后,将3个挂口位的侧向分型与抽芯机构放于定模部分,而将4个凸耳的侧向分型与抽芯机构放于动模部分,模具巧妙地将简化型细水口标准模架用于大水口模具中,利用二次分模过程,分别实现了定模和动模的侧向分型抽芯机构于同一模具之中的抽芯过程,解决了注塑成型后产品侧孔和侧凸耳的脱模问题。经产品大批量的生产检验,模具结构合理,生产效率高,产品质量优。     

内承压外导向侧抽芯注射模

<正> 注塑模具设计中常遇带有侧凹和侧孔的制件,通常采用斜导柱抽芯机构,必然导致模具外形尺寸较为庞大,同时由于受注射机四根拉杆及静动模板尺寸的限制,将需采用较大规格的注射机。为此我们设计了内承压外导向侧抽芯结构的注塑模。(见图一) 该结构的侧向涨模力由芯杆本身的凸台承担,导向部分设在模具外侧,这样侧向涨模力的锁紧楔型块由承压台代替,导向在模外,这样,模具在很大程度上缩减了体积。 由于承压台在工作中要承受剪切及挤压     

潜水泵电机壳体注射模设计

分析了潜水泵电机壳体塑件的结构与成型工艺,针对圆筒形塑件上相互垂直侧孔的成型,在模具上设计了3个侧向分型机构的方案,采用了减少零件间磨损和确保开合模行程的结构,介绍了模具浇注系统、主要成型零件、侧向分型抽芯机构的设计。实践表明:模具结构紧凑、动作可靠,设计方案合理。     

基于UG的风扇调速器上盖注射模设计

以风扇调速器上盖为例,针对制品存在两面散热槽的结构特点,阐述了利用UG软件设计带侧向分型与抽芯机构注射模的方法,介绍了在UG NX环境下进行注射模设计的流程,着重阐述当制品存在侧向孔、槽时,分型面、侧向分型和抽芯机构的设计方法和技巧。指出模具CAD技术的运用可以有效保证注射模设计的准确性,提高设计效率。     

方形壳体的压铸成形

介绍了方形壳体铸件的模具结构,论述了其工作原理。针对侧面带孔的薄壁深腔壳体铸件来说,零件脱模和侧孔抽芯是模具设计的重点,为此采用了弹簧侧抽芯机构和摆钩式顺序分型机构。模具较紧凑,结构较新颖。     

开关插座底壳注射模设计

通过对开关插座塑料底壳塑件结构的分析,介绍了注射模的成型工艺过程,提出了模具采用气动侧向抽芯机构的脱模方式,解决了注射成型后塑件内壁及加强筋上侧孔的脱模问题。经产品大批量的生产检验,该模具结构有效地保证了产品内壁及加强筋上侧孔的成型质量,模具结构的实用效果好。     

方形壳体的压铸成形

介绍了方形壳体铸件的模具结构,论述了其工作原理。针对侧面带孔的薄壁深腔壳体铸件来说,零件脱模和侧孔抽芯是模具设计的重点,为此采用了弹簧侧抽芯机构和摆钩式顺序分型机构。模具较紧凑,结构较新颖。     

带有复杂滑块的注射模设计与制造

注射成型的分流器塑料制品上带有6个侧孔,分别分布在4个不同角度上,难以成型,为了优化模具结构和降低模具制造难度,设计了常规的斜导柱侧向分型抽芯机构和独特的斜向分型抽芯机构,同时也设计了冷却效果优越的冷却系统。     

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。