基于UG注塑模具标准件三维参数化图形库的开发

分析了开发注塑模具标准件三维参数化图形库的必要性,提出了基于UG平台采用VC编译建立新国标注塑模具标准件图形库的思路:通过调用数据库中的参数数据或直接由用户界面输入,应用参数化设计技术在UG中生成标准件实体模型。     

基于CAE的微型机器人模型注塑模设计

针对微型机器人模型的多塑件、多型腔注塑成型的流道不平衡性问题,借助于Moldflow软件的分析结果,提出了一种将点浇口和潜伏式浇口相结合的流道布置方式,其综合了两板模和三板模的结构特点,较好地保证了塑件的成型质量。并详细介绍了模具的浇注系统推、出系统及工作过程。     

NX7 CAD技术在轮胎模具三维造型中的应用

阐述了运用NX7软件的CAD功能进行轮胎模具三维造型的过程,介绍了NX7软件实体造型功能和自由曲面造型功能在轮胎三维造型建模过程中的应用。     

NAK80模具钢表面激光熔覆Ni基碳化钨合金涂层的组织和性能

采用激光熔覆技术,在NAK80模具钢表面制备了Ni基碳化钨合金涂层.研究了激光熔覆涂层的组织结构特点及形成规律,测试分析了其显微硬度的分布特征.结果表明:涂层与基体之间呈良好冶金结合,熔覆层组织主要由树枝晶Cr<,23>C<,6>、未熔碳化钨颗粒相、γ-Ni固溶体及少量分布于固溶体中的NiCr和CrB<,2>相组成;涂...     

模糊控制算法在实时监控系统中的应用

在烧结炉控制系统中,采用B型热电偶配合AD1674实现对烧结炉多点温度的采集,通过查表法达到非线性补偿的目的;控制系统采用C语言模块化编程;在温度控制方案上引入模糊控制算法.由Simulink仿真分析和系统实际运行情况可知:与传统PID算法相比,该算法的控制精度高,可达±0.1℃,系统的动态性能得到改善,鲁棒性增强.     

数控冲床上的浮雕模具设计与制造

介绍了数控冲床结构特点,阐述了数控冲床模具结构设计与制造工艺特点。数控冲床模具具有结构简单、形式多样和可编程排样等特点,模具的结构设计与制造具有较高的特殊要求。针对典型的浮雕模具采用一种实用的高效率的模具结构设计及其制造工艺,降低了数控冲床模具制造成本。     

稀土Ce对Al-12Si合金微观组织影响

本文以Al、Al-Si、Al-Ce高纯组元配置一定质量百分比的Al-Si-Ce合金,采用多功能真空电弧熔炼炉YSU-ZZ进行熔炼,使用铜模吸铸法制备样品并对样品进行金相显微镜、扫描电镜(SEM)及能谱分析(EDS).重点研究了Ce的加入量及冷却速度等因素对共品硅的大小、形状和分布的影响.研究表明快速凝同可以很好的细化共...     

Numerical study of macrosegregation formation of ingot cast in normal sand mold and water-cooled sand mold

Formation of macrosegregation of 5 t steel ingots cast in sand molds with and without water-cooled copper tube is simulated by solving macroscopic mass,momentum,species and energy conservation equations with the consideration of shrinkage formation.Predicted macrosegregation pattern of the ingots shows a fair agreement with the experimental data.Both calculations and experiments reveal that some positive segregation patches are formed at the bottom of ingot.With the water-cooled copper tube inserted in the ...     

Accelerated Mold Test on Dried Pine Sapwood Boards: Impact of Contact Heat Treatment

Abstract

We test the hypothesis that the combination of kiln drying of double-stacked boards and contact heat treatment will reduce the susceptibility of treated boards to colonization by mold fungi. Winter-felled Scots pine (Pinus sylvestris L.) sapwood boards were double-stacked in an industrial kiln in ‘‘sapwood out’’ and ‘‘sapwood in’’ positions. Dried samples were then contact heat-treated using a hot press at three different temperatures (140°C, 170°C, and 200°C) for three different periods (1, 3, and 10 min). An accelerated mold test was performed in a climate chamber where naturally mold-infected samples were used as a source of mold inocula. Contact heat treatment degraded the saccharides that accumulated at dried surfaces, and reduced the mold growth. The threshold temperature and time for inhibiting mold growth were 170°C for 10 min. However, for industrial application, the most feasible combination of temperature and time would be 200°C for 3 min. We concluded that double stacking/contact heat treatment used is an environmentally friendly alternative to chemicals for reducing mold on Scots pine sapwood boards.     

The effects of gas counter pressure and mold temperature variation on the surface quality and morphology of the microcellular polystyrene foams

In this study, we developed a foaming control system using the Gas Counter Pressure (GCP) combined with mold temperature control during the microcellular injection molding (MuCell) process and investigated its influence on the parts' surface quality and foams structures. The results revealed that under GCP control alone when GCP is greater than 10 MPa, part surface roughness for transparent polystyrene (PS) improved by 90%. When GCP increased, the skin thickness also increased, the weight reduction decreased and the average cell size reduced to about 30 μm. For black PS parts, when GCP is greater than 10 MPa, the part gloss reaches the same value as that molded by conventional injection molding. By increasing gas holding time, the cell density decreased and the cell size distribution became more uniform. The increase in amount of supercritical fluid foaming agent also increased the cell density. Applying mold temperature control alone with temperature in the range of 90–120°C (near T_g), the surface roughness improved by 65%. Increasing mold temperature decreased the skin thickness; however, the cell size distribution became significantly nonuniform. It was found that thin skin, small and uniform cell size as well as good surface quality can be achieved efficiently by simultaneous combining of GCP and mold temperature control. The proposed innovative approach may lead to a significant improvement and a more broad application for MuCell process. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013