共查询到19条相似文献,搜索用时 171 毫秒
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李喜红 《特种铸造及有色合金》2009,29(5)
通过对离心铸坯、热挤压成形技术特点的分析及不锈钢机械密封弹簧座离心铸坯-热挤压联合成形新工艺实践和经济效益的研究,表明离心铸坯-热挤压联合成形新工艺,发挥离心铸造,挤压两种工艺的优势,具有缩短工艺流程、提高材料利用率、节约能源、改善制件内在品质等优点.生产100 t成品可节约材料费300余万元. 相似文献
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H型钢通常采用焊接和热轧的成形方法获得,而采用热挤压成形技术生产H型钢目前并没有成熟工艺,在国内也没有相关案例.成形技术的难点在挤压设备能力、变形工艺、实心坯料加热、工模具设计及玻璃润滑等.介绍了TP304A不锈H型钢的热挤压成形工艺,通过塑性变形、加热、工模具设计和玻璃润滑等技术上的突破,采用60MN挤压机成功将外径为φ388mm的实心坯料热挤压成形为外接圆φ311mm的H型钢.经检验,表面质量、尺寸精度均达到了设计要求. 相似文献
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通过对螺旋矩形内齿成形特点的分析,确定采用热挤压工艺成形该零件。介绍了毛坯制定、加热工艺及设备、挤压设备选择、模具设计、润滑与冷却等整个工艺过程,并对采用普通压力机进行热挤压成形进行了计算与分析。 相似文献
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触头成型工艺分析与挤压模设计 总被引:1,自引:0,他引:1
在铜铬触头成型工艺分析的基础上,用不同的热挤压成型工艺方案对材料的利用率进行了分析对比,运用活动凹模对异型静触头进行了热挤压,材料利用率和生产效率得到大幅度提高。 相似文献
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Effects of Reinforced Particles on Dynamic Recrystallization of Mg Base Alloys during Hot Extrusion 总被引:1,自引:0,他引:1
主要研究了SiC颗粒增强镁基复合材料在不同挤压比、不同挤压温度下进行挤压后,SiC颗粒对镁合金基体中的动态再结晶现象影响。结果表明:挤压过程中颗粒周围产生了颗粒变形区(PDZ),并且颗粒变形区在低温挤压时以细小动态再结晶晶粒为主。颗粒促进动态再结晶晶粒形成的主要原因是颗粒周围较高的位错密度以及大的晶粒取向梯度。SiC颗粒对镁合金基体动态再结晶的影响主要有两方面:一方面,颗粒促进动态再结晶的形核以及生长,另一方面,当再结晶晶粒晶界碰到颗粒时,颗粒阻止了晶粒的继续长大。 相似文献
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Carbon nanofiber(CNF)-reinforced aluminum-matrix composites were fabricated via ball milling and spark plasma sintering(SPS), SPS followed by hot extrusion and powder extrusion. Two mixing conditions of CNF and aluminum powder were adopted: milling at 90 rpm and milling at 200 rpm. After milling at 90 rpm, the mixed powder was sintered using SPS at 560 °C. The composite was then extruded at 500 °C at an extrusion ratio of 9. Composites were also fabricated via powder extrusion of powder milled at 200 rpm and 550 °C with an extrusion ratio of 9(R9) or 16(R16). The thermal conductivity and tensile properties of the resultant composites were evaluated. Anisotropic thermal conductivity was observed even in the sintered products. The anisotropy could be controlled via hot extrusion. The thermal conductivity of composites fabricated via powder extrusion was higher than those fabricated using other methods. However, in the case of specimens with a CNF volume fraction of 4.0%, the thermal conductivity of the composite fabricated via SPS and hot extrusion was the highest. The highest thermal conductivity of 4.0% CNF-reinforced composite is attributable to networking and percolation of CNFs. The effect of the fabrication route on the tensile strength and ductility was also investigated. Tensile strengths of the R9 composites were the highest. By contrast, the R16 composites prepared under long heating duration exhibited high ductility at CNF volume fractions of 2.0% and 5.0%. The microstructures of composites and fracture surfaces were observed in detail, and fracture process was elucidated. The results revealed that controlling the heating and plastic deformation during extrusion will yield strong and ductile composites. 相似文献
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在电弧强干扰下,管道焊接机器人抗干扰设计成为管道焊接过程稳定性关键,其中管道焊接机器人抗干扰电路设计是主要影响因素之一。通过对管道焊接机器人复位电路、时钟电路、电源电路、机械开关触点电路和弧压采样线路的分析,提出相应处理措施:采用MAX692A硬件看门狗和屏蔽双绞线技术;设计抗干扰时钟脉冲电路;设计低通滤波器滤滤除供电线路高频电磁干扰;主控制板供电电源采用分离式专用微机开关电源供电;采用光电隔离和软件延时消除机械开关触点干扰;在电弧电压采样电路中采取隔离吸收等措施。 相似文献
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Microstructure and properties of AZ80 magnesium alloy prepared by hot extrusion from recycled machined chips 总被引:5,自引:0,他引:5
1 INTRODUCTIONMagnesiumalloyshavemanyadvantagessuchaslowdensity ,highspecificstrength ,goodelectromag neticshieldingcharacteristics ,excellentcastabilityandmachinabilityetc .Magnesiumisanabundantele mentsinceabout 1.93% (massfraction)ofearthcrustconsistofmagne… 相似文献