排序方式： 共有27条查询结果，搜索用时 15 毫秒
1.
本文采用有限元法对正挤压凹模的应力状况进行了分析计算,根据计算结果,对BJ130汽车轮胎螺母终成形凹模进行了改进设计.实践证明,使用改进后的凹模结构,可使模具寿命提高五倍以上. 相似文献
2.
问庆宝 《南京林业大学学报(自然科学版)》1988,(4)
用挤压法将浸泡合成树脂胶的竹丝模压成型为纺织梭子,其加工工艺简单、性能良好、强度较高,被用来代替木质织梭。 模具的设计和制造在模压制品的制造工艺中是非常重要的,它将决定模压制品的性能和成本。本文所介绍的模具,其压制零件的脱模操作既方便又快速。该模具的高度尺寸小,热传导效率高,降低了织梭的生产成本。 相似文献
3.
The microstructure, mechanical property, electrochemical behavior and biocompatibility of magnesium alloy(Bio De MSMTM) were studied in the present work. The experimental results demonstrated that grain refining induced by extrusion improves the alloy strength significantly from162 MPa for the as-cast alloy to 241 MPa for the as-extruded one. The anticorrosion properties of the as-extruded alloy also increased.Furthermore, the hemolysis ratio was decreased from 4.7% for the as-cast alloy to 2.9% for the as-extruded one, both below 5%. Bio De MSMTMalloy shows good biocompatibility after being implanted into the dorsal muscle and the femoral shaft of the New Zealand rabbit, respectively, and there are no abnormalities after short-term implantation. In vivo observation indicated that the corrosion rate of this alloy varies with different implantation positions, with higher degradation rate in the femur than in the muscle. 相似文献
4.
Hongju Deng Yan Yang Minmin Li Xiaoming Xiong Guobing Wei Weidong Xie Bin Jiang Xiaodong Peng Fusheng Pan 《自然科学进展(英文版)》2021,31(4):583-590
The as-cast Mg–6Li–4Zn-x Mn alloys were prepared and extruded at 280℃ with an extrusion ratio of 25:1. The effects of Mn content on the microstructure and mechanical properties of Mg–6Li–4Zn-x Mn alloys were investigated in this study. The XRD results show that Mg–6Li–4Zn–x Mn alloys consisted of α-Mg(hcp) + β-Li(bcc)duplex structured matrix, Mg Li2Zn and Mn phases. The grains of the extruded Mg–6Li–4Zn–x Mn alloys were refined by dynamic recrystallization during the extrusion process... 相似文献
5.
利用上限元法（ＵＢＥＴ）模拟了圆柱直齿轮径向挤压过程的变形力规律。经验证,所用的计算方法及计算机程序是正确、可行的。模拟结果对生产实践具有重要的指导意义。 相似文献
6.
本文报导了对供应状态时效硬化的超硬铝合金L_(c4)进行的超塑拉仲试验以及对一种带有轴向狭长筋板零件进行的网格法模拟成型试验和横向超塑挤压成型试验的结果。分析了在超塑状态下,金属在轴向狭长槽型腔中的流动规律。结果表明:在一定温度和变形速率条件下,该合金也具有一定的超塑性。同时成功地实现了狭长筋板零件的超塑成型。 相似文献
7.
通过对钻柄温挤成型工艺过程和成型模具的分析,找出了凸模拉断、凹模开裂的主要原因为：成型压力、模具结构与制造、成型设备等,采取了相应的措施,提高了模具的使用寿命。 相似文献
8.
Finite element method was employed to investigate the effect of process parameters of plastic deformation behavior in Forward-Backward-Radial Extrusion (FBRE) process. The result of an axisymmetric model shows that the friction between die components and the sample has a substantial effect on the material flow behavior. Although strain heterogeneity index (SHI) slightly decreases with an increase in friction, large portion of the sample experiences significant strain heterogeneity. Increasing the friction factor also localizes the strain heterogeneity effect in the backward section, and spread the effect in the forward section. Decreasing the friction in the FBRE process can reduce the amount of the strain heterogeneity in the product while decreases the required punch force substantially. Furthermore, an increase in gap thickness increases the deformation in the area close to the lower punch at the expense of the area in the vicinity of the upper punch. The numerical simulation has a good agreement with the experimental results which confirms the accuracy of the proposed finite element model. 相似文献
9.
本文对带爪盘形类非轴对称零件(如摩托车齿轮、拖拉机转向齿轮等)的复合挤压变形规律进行了实验和理论研究。用弹塑性有限元法开发了三维弹塑性有限元程序,并利用该程序对非轴对称零件的复合挤压变形进行了数值计算分析。用有限元法所得的理论计算值与实验研究结果吻合。 相似文献
10.
传统模具设计在选材时对于经验依赖性强 ,且具有盲目性 ,不利于实现设计过程的计算机化。本文以传统解析法作为凹模设计的理论基础 ,综合分析了影响凹模强度及总直径比的各个因素 ,进一步研究参数、σsi、pi、α之间的相互关系 ,确定出适合于单层凹模冷挤压的压力范围 ,从而使模具层数预估 ,材料选用 ,以及设计过程更合理 相似文献