液晶投影仪上面板注射模设计

分析了液晶投影仪上面板结构和成型工艺,介绍了注射模结构、工作过程和关键机构,还介绍了针阀式热流道在模具中的应用。经过生产验证,模具结构合理、可靠,对类似制品的注射模设计具有一定的参考价值。     

循环高热温度下PMC材料的使用寿命预测

通过引入温度对水泥基材料力学性能的影响,修正了水泥基材料使用寿命的计算模型,从而得到普通水泥基材料、原有灌浆材料和聚合物水泥基(PMC)材料使用寿命和实际使用温度之间的关系,同时通过室内模拟试验和工程现场的实际情况对计算结果进行了验证。     

Prediction of central bursting defects in rod extrusion process with upper bound analysis method

The prediction of central bursting defects in the rod extrusion process through conical dies using the upper bound analysis is investigated. A kinematically admissible velocity field, including the radial and angular velocity components, is proposed. A new criterion is presented to predict the occurrence of the central bursting defects. Parameter b_obt, which represents the risk probability of cracking, is proposed. It is calculated using the shape of the boundary at the entrance by minimizing the total power dissipation during the extrusion process. When b_obt is equal to or greater than b_cr, central bursting occurs. Furthermore, the quantitative relationships between central bursting defects and process parameters (semi die angle, reduction in area and frictional factor) are studied. The results show that the central bursting defects are affected primarily by the reduction in area and the friction factor. The presented criterion is verified by comparing with the FEM simulation data and the results of the published paper.     

中间包透气上水口的研制与使用

本文介绍了中间包用新型透气上水口的研制过程、生产工艺及在钢厂的使用情况。     

连铸中间包透气上水口的研制与应用

介绍了连铸中间包透气上水口的性能和种类及连铸工艺对透气上水口性能的要求。利用合成莫来石颗粒、α-Al     

汽车门框上条制件拉弯成形模具设计简

汽车门框、窗框多由各种复杂截面型材弯曲成形后焊接而成,型材截面复杂,并且形状多为空间三维曲面,该类复杂截面型材的高精度弯曲成形是制造汽车门框和窗框的关键技术。通过分析某汽车门框上条制件的成形工艺特点,综合比较各种弯曲方式后选取了张臂式拉弯成形工艺,并设计了拉弯成形模具、切断机构、冲孔及辅助成形装置,利用该模具可以成形出符合制件质量要求的车门框上条工件。     

UBET analysis of process of extruding aluminum alloy ribbed thin-wall pipes through a porthole die

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中梁上盖板焊接反变形压型工艺探讨

针对中梁上盖板压制反变形时弯曲角度小、回弹量大,成形质量不稳定的现状,分析了Q450NQR1高强钢的成形特性,阐述了压型模具的结构及工作原理.通过计算工艺参数,指出了现有工艺的不足,提出了改进措施.结果表明:新模具可使反变形波动合理,压型返修率明显降低,提高了工效.     

多功能酸洗缓蚀抑雾剂的后效性能研究

本文采用线性极化法测定了多种酸洗体系加入多功能酸洗缓蚀抑雾剂CQH-2前后的极化电阻，研究了缓蚀剂的缓蚀效率随时间的变化关系，以评定CQH-2缓蚀剂的后效性能。结果表明：CQH-2在多种酸洗体系中后效性能良好，仅在铝的酸洗中，缓蚀率和后效性能均较差，加入吖啶后，缓蚀率和后效性能都显著提高。     

Effect of die inlet geometry on extrusion of clover sections through curved dies: Upper bound analysis and experimental verification

The effect of die inlet and transition geometry on the extrusion loads and material flow for extrusion of clover sections were investigated and presented both theoretically and experimentally. For this purpose, four different die geometries including straight tapered and cosine transition profile and each of them having round and clover inlet geometries were chosen. In the experimental study, commercially pure lead was used because of its hot forming characteristic at room temperature. A newly kinematical admissible velocity field to analyze different profiles of extrusion dies of clover section from round bars was proposed by upper bound analysis. It is clear that the extrusion loads obtained from the theoretical analysis for various die inlet-die transition geometry combinations are in good agreement with the experimental results. Axis deviations of the parts which define the dimensional quality of the products were also investigated.