基于CAD/CAE/CAM技术的电话机注塑模设计

介绍了Pro/E在注射模具设计中的应用和基于Moldflow软件的注射成型分析以及在UG环境下的CAM模拟。通过实例阐述了采用CAD/CAE/CAM技术进行电话机注塑模的设计和分析过程,并运用UG软件对该零件型腔进行了加工刀路设计,模拟了数控加工过程。采用CAD/CAE/CAM技术可以缩短产品的开发周期,提高设计质量。     

CAD/CAE技术在注射模设计中的应用

介绍了计算机辅助设计(CAD)技术在注射模具设计中的应用,采用计算机辅助工程(CAE)软件进行注塑成型分析.通过实例,阐述了应用CAD/CAE软件进行注射模设计的流程和利用Pro/E软件进行注射模具设计的具体方法,以及运用Moldflow软件进行填充、冷却等分析,得到合理的注射工艺参数,优化了模具结构.采用CAD/CAE技术可以缩短产品的开发周期,提高设计质量.     

基于Pro/E和Cimatron E的注塑模具设计与加工

采用多种软件联合应用,以手表壳注塑模为例,介绍了Pro/E在注塑模具设计中的应用以及在Cimatron E环境下的CAM(计算机辅助制造)实现。阐述了Pro/Moldesign的模具设计流程和优势,并运用Cimatron对手表壳凹模进行了仿真模拟加工。通过实例分析表明,两者结合使用能缩短模具生产周期和提高模具精度。     

基于CAD/CAE/CAM技术的按键注塑模具设计

分析了按键结构特点,以Moldflow为工具,对按键的注塑成型过程进行CAE模拟分析,确定了模具的浇注系统以及冷却系统。在模拟分析的基础上运用Pro/E软件完成了模具的三维分模,将Pro/E中提取的加工信息,导入到MasterCAM软件中进行模具零件的数控自动编程和模拟加工。与传统的注塑模具设计方法相比,基于CAD/CAE/CAM技术提高了模具设计的效率,缩短了模具设计和制造周期,降低了成本。     

注塑模具的计算机辅助制造

介绍了注塑模具的计算机辅助制造(CAM)技术及其优越性和有待解决的问题,并就CAD/CAM集成系统进行了阐述。     

CAD/CAE/CAM技术在模具设计制造的应用

三维建模已经越来越广泛地应用于注塑模具设计。本文在Pro/ENGINEER软件应用实践的基础上,以手机模型为例,系统全面地从三维造型、模具设计、成型仿真和刀具路径等方面对注塑模具CAD/CAE/CAM技术进行归纳和阐述,着重探讨了关键过程的方法和措施。Pro/E软件在建模方面的实用性界面和功能在该项设计中重点介绍。     

UG软件CAD/CAM技术在注塑模生产中的应用

以手机外壳为例，介绍利用UG软件提供的MoldWizard和CAM数控编程两大模块，实现从模具设计到数控铣加工的全过程。     

CAD/CAE/CAM在注塑模设计中的应用

详细介绍了基于Pro/E软件的注塑模设计,利用Moldflow软件进行注塑分析模拟,并在MasterCAM软件中进行模具的模拟加工和数控编程,将三者集合成一个完整的注塑模CAD/CAE/CAM系统,为注塑模具设计制造提供有效的途径。     

基于UG和Master CAM的LCD盒注塑模具设计与加工

以LCD盒塑件为例,利用UG软件对注塑模具进行了设计,并运用Master CAM软件对模具型腔进行了数控加工。结果表明:UG和Master CAM两个软件相结合,不仅能够提高注塑模具设计与加工的质量和效率,而且能够缩短模具生产周期。     

基于Pro/E的照相机外壳注射模具设计

以照相机外壳为例,在介绍了最新的Pro/engineer软件特点和模具设计流程的基础上,运用Pro/E+EMX对该注射与传统的注射模设计相比,运用Pro/E软件进行模具三维设计,可以大大缩短模具设计周期,降低模具设计成本。     

Wet Milling of Fe/Al/Al2O3 and Fe2O3/Al/Al2O3 Powder Mixtures

Wet milling of Al₂O₃-aluminide alloy (3A) precursor powders in acetone has been investigated by milling Fe/Al/Al₂O₃ and Fe₂O₃/Al/Al₂O₃ powder mixtures. The influence of the milling process on the physical and chemical properties of the milled powders has been studied. Particle refinement and homogenization were found not to play a dominant role, whereas plastic deformation of the metal particles leads to the formation of dislocations and a highly disarranged polycrystalline structure. Although no chemical reactions among the powder components in Fe₂O₃/Al/Al₂O₃ powder mixtures were observed, the formation of a nanocrystalline, ordered intermetallic FeAl phase in Fe/Al/Al₂O₃ powder mixtures caused by mechanical alloying was detected. Chemical reactions of Fe and Al particle surfaces with the atmosphere and the milling media lead to the formation of highly porous hydroxides on the particle surfaces. Hence the specific surface area of the powders increases, while the powder density decreases during milling. The fraction of Fe oxidized during milling was determined to be 0.13. The fraction of Al oxidized during milling strongly depends on the metal content of the powder mixture. It ranges between 0.4 and 0.8.     

Preparation and properties of poly(Nε,Nε-dicarboxymethyl-l-lysine)

A new ampholytic homopolypeptide, $\text{poly}\text{(N}{}^{\mathrm{\epsilon }}\text{,N}{}^{\mathrm{\epsilon }}\text{-}\text{dicarboxy-methyl-}\text{l}\text{-lysine}\text{)}$, which has one tertiary amino and two carboxyl groups in the side chain has been derived from a hydrochloride salt of poly(L-lysine). The polymer in aqueous solution seems to be in the coil form with locally extended structure (LES) at neutral pH. In both the acidic and alkaline regions, the molar ellipticity of the polymer changes as a result of change in net charge on the side chain. The conformational changes may be from the coil with LES to other coiled forms. 5–7 M NaClO₄ and 80% aqueous methanol induce the α-helix in the polymer at neutral pH. Divalent cations, Cu²⁺ and Ca²⁺, do not induce any remarkably ordered structures such as α-helix or β-structure in the polymer in aqueous solution at any pH. Ultraviolet absorption studies show an absorption peak of the polymer-Cu²⁺ complex near 240 nm. Dependence of the peak intensity on pH at various q values ($\text{q =}\text{[}\text{Cu}{}^{\mathrm{2+}}\text{]}\text{[}\text{residue}\text{]}$) indicates the two steps of the complex formation. At q less than 0.64, the formation is described only with the first step. An average coordination number for Cu²⁺ at the first step was calculated to be about 2 by the method of Mandel and Leyte. The association constant of Cu²⁺ with the residue at the step was determined from the absorption data to be far smaller than that for the Cu²⁺-EDTA complex. The second step of the formation occurs in the case of large q but the absorption data for the second step cannot be obtained exactly due to precipitation.     

Sintering of Si3N4-Y2O3-Al2O3

Sintering kinetics of the system Si₃N4-Y2O₃-Al₂O3 were determined from measurements of the linear shrinkage of pressed disks sintered isothermally at 1500° to 1700°C. Amorphous and crystalline Si₃N₄ were studied with additions of 4 to 17 wt% Y₂O₃ and 4 wt% A1₂O₃. Sintering occurs by a liquid-phase mechanism in which the kinetics exhibit the three stages predicted by Kingery's model. However, the rates during the second stage of the process are higher for all compositions than predicted by the model. X-ray data show the presence of several transient phases which, with sufficient heating, disappear leaving mixtures of β ' -Si₃N₄ and glass or β '-Si₃N₄, α '-Si₃N₄, and glass. The compositions and amounts of the residual glassy phases are estimated.     

Participation of lewis base on vinyl chloride polymerization with Al(C2H5)3CCl4 catalyst system

The polymerization of vinyl chloride has been investigated using an $\text{Al}\text{(}\text{C}{}_2\text{H}{}_5\text{)}{}_3\text{CCl}{}_4$ catalyst system in the presence of various Lewis bases. Effective Lewis bases are γ-butyrolactone, diglyme and diethylenetriamine which are multidentate. The rate of polymerization is dependent not only on the basicity of the Lewis base used but also on a coordination number of one. The latter is the predominant factor. For the effect of polymeric amines, a tentative hypothesis is discussed.     

Ag2O-Doped Bi2Sr2Ca1Cu2Ox Superconductors Prepared via Melt-Quenching

Ag₂O-doped superconducting Bi₂Sr₂Ca₁Cu₂O _x ceramics were prepared by a melt-quenching–reheating method. It is found that the Ag₂O-doped, as-cast specimens exhibit superconductivity ( T _c= around 80 K) by heat treatment at temperatures around 800°C even in an evacuated and sealed silica glass tube, while the undoped specimens do not and vaporize by the corresponding heat treatment. Conversion of the Ag₂O-doped, as-cast specimens into superconducting ceramics when heated in an evacuated vessel is explained in terms of the oxygen donor of Ag₂O in the specimen. This finding enables us to fabricate a desired shape of superconducting Bi₂Sr₂Ca₁Cu₂O _x ceramics sealed in metals or glasses. The addition of Ag₂O to Bi₂Sr₂Ca₁Cu₂O _x melt, however, had deleterious influences on the superconducting properties ( T _c and J _c) of the resultant ceramics when obtained by heat treatment in air.     

Synthesis and Characterization of Ti0.33Ta0.33Nb0.33C and Ti0.33Ta0.33Nb0.33CxN1-x Whiskers

Ta_0.33Ti_0.33Nb_0.33C and Ta_0.33Ti_0.33Nb_0.33C _x N_{1− x} whiskers were synthesized via a carbothermal vapor-liquid-solid growth mechanism in the temperature range 900°-1450°C in Ar or N₂. The optimum temperature was 1250°C. Whiskers were obtained in a yield of 70-90 vol%. The whiskers were 0.5–1 µm in diameter and 10–30 µm in length. The starting materials that produced the highest whisker yield were: TiO₂, Ta₂O₅, Nb₂O₅, C, Ni, and NaCl. C was added to reduce the oxides, and Ni to catalyze whisker growth. NaCl was used as a source of Cl for vapor-phase transportation of Ta and Nb oxochlorides and Ti chlorides to the catalyst. The catalyst metal was recycled several times during the synthesis and was transported as NiCl₂( g ) according to thermodynamic calculations. The rate of formation and the chemical composition of the whiskers depended on the synthesis temperature, the choice of catalyst, and the atmosphere. At low temperatures, the whiskers were enriched in Nb and Ta, whereas the Ti content increased with increased synthesis temperature.