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移动磁场直线电机的研制及其应用效果 总被引:2,自引:0,他引:2
以工业用铝质散热片作为研究对象,针对薄壁铝件液态成型难题,自行设计与制作了的平板型直流电机;采用石膏铸型,利用电机所产生稳定可调的移动磁场研究了薄壁铝质散热片的液态成型工艺,结果表明:以不锈钢为底板,采用移动磁场液态成型法(电压为240V)可增强液态金属的充型压头,获得外观完整的铝质薄壁件. 相似文献
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基于脉冲微束等离子弧焊的快速成形系统中实时自适应送丝方式 总被引:1,自引:0,他引:1
对基于脉冲微束等离子弧焊的直接金属快速成形系统中,填充金属丝的熔滴过渡方式和送丝方向对成形轨迹质量的影响进行了研究。研究结果表明:“搭桥过渡”方式形成的轨迹形态连续、光滑;送丝方向固定的方式在成形与送丝方向间夹角过大的轨迹时,会发生熔滴未完全熔于熔池、金属丝与已凝固成形轨迹发生干涉等缺陷。根据研究结果研制了一个基于成形件断面轮廓实时调整送丝方向的自适应送丝子系统。论述了转角、合成速度、加速度等控制参数的确定算法。对自适应送丝方式和方向固定的送丝方式进行了对比试验。结果显示:自适应送丝方式避免了熔滴未完全熔于熔池、金属丝与已凝固成形轨迹发生干涉等缺陷,对保证成形轨迹的质量有显著作用。 相似文献
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针对大型中空异形变截面复合材料的大长径比、中空、异形、变截面、变壁厚等特殊结构的成型工艺进行研究。根据复合材料的结构和选材分析,确定成型工艺路线和成型工艺参数。通过试验件的试验验证,结合成型质量分析发现,延长树脂流动段和后固化阶段的保温时间,并减小复合材料内部的温度梯度,可以有效提升树脂的固化程度并降低成型过程中的内应力。对工艺参数进行优化后,复合材料内部的分层与孔隙缺陷情况明显改善,缺陷尺寸在长度和宽度方向分别减少至15.6%和24.9%,有效改善了大型中空异形变截面复合材料的成型质量。 相似文献
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张友宏 《中国制造业信息化》2007,36(21):64-66
ABS塑料在注塑成型薄壁件时,制品常因复杂的变形而产生翘曲现象.根据翘曲变形理论,通过Pro/E厄建立薄壁件模型,利用Moldflow软件模拟研究了浇口位置、保压和冷却过程对翘曲变形的影响,进行翘曲变形预测,以优化薄壁件注塑成型工艺过程设计,提高生产效率和成形质量. 相似文献
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张友宏 《中国制造业信息化》2007,36(11):64-66,70
ABS塑料在注塑成型薄壁件时,制品常因复杂的变形而产生翘曲现象。根据翘曲变形理论,通过Pro/E建立薄壁件模型,利用Moldflow软件模拟研究了浇口位置、保压和冷却过程对翘曲变形的影响,进行翘曲变形预测,以优化薄壁件注塑成型工艺过程设计,提高生产效率和成形质量。 相似文献
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基于ALE算法的空心薄壁铝型材模具结构优化 总被引:1,自引:0,他引:1
针对空心薄壁铝合金型材挤压成型后薄壁内凹缺陷进行了数值模拟分析,得到了其在稳态时不同方向上的金属流速分布及在焊合室内的金属压力分布状况。模拟结果表明:由于截面上不同部分之间产生了较大的流速差,且金属在不同方向上的流速不相同,从而导致了缺陷的存在。根据分析采用了增加阻流块的设计方案,以此达到阻碍金属流动,减小流速差的目的。经过仿真计算发现修改后的模具结构最终能获得合格的产品。 相似文献
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针对一般非金属类薄壁件注塑成型周期较长、成型精度不高、耗时耗材的问题,提出了一种结合三维激光扫描技术和3D打印技术的非金属薄壁件成型方法。以摩托车薄壁件拐板为对象,首先,选用逆向工程的点云采集技术和点云处理技术,获取了工件精确表征点云数据;然后,通过模型重构与分析技术,设计出了尺寸和表征数据均满足工件要求的模型;其次,运用3D打印前处理技术,进行了模型摆放、支撑添加与切片等操作;最后,使用SLA工业打印机打印出了摩托车薄壁拐板工件。研究结果表明:经过20 h左右工件打印成型,较传统注塑成型明显缩短了试制周期,且该成品尺寸偏差以及表面曲率特征均满足工件要求;该方法适用于工业制造中非金属薄壁件的打印成型,可用于产品前期试制研发,可有效缩短测试周期,降低成本。 相似文献
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采用冷金属过渡加脉冲(CMT+P)电弧增材制造4043铝合金薄壁件,对比了不同工艺参数下薄壁件的成形性能,研究了成形性能良好薄壁件的组织与拉伸性能,并与CMT工艺下的进行了对比。结果表明:CMT+P工艺下,当焊接速度为8 mm·s-1和送丝速度4 m·min-1时,薄壁件的成形性能最好,且其成形效果接近CMT工艺下的; CMT+P工艺下薄壁件的单层组织由焊道上层的细晶区和焊道下层的粗晶区组成,焊道间存在穿过界面生长的粗大柱状枝晶,CMT工艺下的显微组织为分布均匀的细小柱状晶; CMT+P工艺下薄壁件的拉伸性能优于CMT工艺下的; CMT+P工艺下横向和纵向拉伸试样断裂方式均为韧性断裂,横向与纵向抗拉强度各向异性百分比仅为4%,说明薄壁件的力学性能不存在各向异性。 相似文献
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Chunze Yan Yusheng Shi Jingsong Yang Jinhui Liu 《The International Journal of Advanced Manufacturing Technology》2010,51(9-12):973-982
The amorphous polymer of polystyrene (PS) has been widely used in the selective laser sintering (SLS) process. However, PS is not suitable to make parts with thin-wall or delicate structures because of the poor mechanical properties of its SLS parts. Therefore, styrene–acrylonitrile copolymer (SAN), another kind of amorphous polymers, was investigated as an SLS material. The effects of laser energy density on the relative density, mechanical properties, and dimensional accuracy of the SLS parts were studied, and the properties of PS and SAN SLS parts were compared. The postprocessing method of infiltrating with epoxy resin was used to reinforce the green SAN SLS parts. The results show that there is little difference in the relative density between the SAN and PS SLS parts, while the flexural strength of the SAN SLS specimens is obviously higher than that of the PS SLS specimens at the same energy density. After the postprocessing, the flexural strength, flexural modulus, and impact strength of the SAN SLS specimens increase by 133%, 4394%, and 254%, respectively, and the SLS parts maintain relatively high-dimensional accuracy although slight shrinkage occurs due to epoxy resin cure. SAN can be used to fabricate SLS parts with more complex and delicate structures. 相似文献
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设计了一种回转阴极表面电铸液高速冲刷与高电流密度沉积交替进行的电铸铜加工方式,以提高回转件表面电铸铜沉积效率和沉积层质量.在溶液冲刷速度为3m/s左右的条件下,分别以4、8、12、16 A/dm2的电流密度进行电化学沉积,并对电铸铜层进行力学性能检测.检测结果显示:8 A/dm2电流密度下获得的电铸层综合力学性能最优良... 相似文献
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It can be known from a large number of research results that improving the dispersibility of CNTs can effectively opti-mize the mechanical properties of the corresponding metal matrix composites.However,the crucial issue of increas-ing the bonding of CNTs and the matrix is still unsolved.In this paper,a novel method was developed to increase interfacial bonding strength by coating titanium oxide(TiO2)on the surface of CNTs.The rare earth Pr and TiO2@CNTs-reinforced AZ91 matrix composites were successfully fabricated by powder metallurgy.Hot press sintering and hot extrusion of the milled powder was performed.After hot extrusion,the influence of TiO2@CNTs on the microstruc-ture and mechanical properties of the composites were investigated.The results showed that the coating process can improve the distribution of CNTs in Mg alloy.The CNTs refined the grains of the matrix,and the CNTs were presented throughout the extrusion direction.When the TiO2@CNTs content was 1.0 wt.%,the yield strength(YS),ultimate ten-sile strength(UTS),and elongation of the alloy attained maximum values.The values were improved by 23.5%,82.1%,and 40.0%,respectively,when compared with the AZ91 alloy.Good interfacial bonding was achieved,which resulted in an effective tensile loading transfer at the interface.CNTs carried the tensile stress and were observed on the tensile fracture. 相似文献
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Hossein Gheshlaghi Gadim Ali Doniavi 《Journal of Mechanical Science and Technology》2018,32(3):1135-1142
In this study, a syringe pump was designed and built to determine the effect of the physical properties of the spinning part of a machine and the physical properties of the wet spinning process. Through the wet spinning method and fuzzy separation process, solid fibers were produced under experiments designed by the response surface method and statistical model of composite center design to predict the exact tensile strength. Polymeric fibers produced by atomic absorption spectrometry were used as adsorbent. This study aimed to evaluate the effects of spinning velocity, length-to-diameter ratio of the spinner, spinner diameter, and weight percentage of the polymer on the mechanical properties and structure of the sample. Scanning electron microscopy tests were conducted on the samples to analyze their structural properties, and the output pictures showed that the samples had a desirable microstructure. Analysis of variance indicated that the physical parameters of spinning produced the most significant effect on improving fiber properties. Results of data analysis showed that the length-to-diameter ratio and spinner diameter were the most effective process conditions that could be used to examine the data on tensile strength and optimum ratio of fiber diameter to spinner diameter. Finally, optimization was performed using the utility function to maximize the amount of tensile strength, and the process experimental results were evaluated. The results showed that the response surface models could adequately predict the values of the response variable. The gage R&R method was used to determine the amount of error due to the measurement system. 相似文献
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研究了激光选区烧结(SLS)成型工艺中不同工艺参数以及后续热处理工艺对超高分子量聚乙烯(UHMWPE)材料成型性能的影响。通过调整扫描间距、激光功率、扫描速度等不同工艺参数,描述了SLS成型UHMWPE零件的致密度、拉伸强度以及断裂伸长率,并对热处理前后的SLS成型UHMWPE零件的力学性能进行了比较。结果显示,致密度、拉伸强度、断裂伸长率总体上与激光功率呈正相关关系,与扫描间距、扫描速度呈负相关关系。经热处理后,SLS成型UHMWPE零件的力学性能有明显提高,致密度达到95.12%,抗拉强度达到24.08 MPa,断裂伸长率达到334.82 MPa。实验结果表明:SLS成型UHMWPE零件与模塑成型UHMWPE零件性能尚有差距,仅优化成型工艺不足以得到理想性能,但经热处理后,零件性能基本满足使用要求。 相似文献