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2024/3003 gradient aluminum alloy was prepared by semi-continuous casting using double-stream-pou-ring technique. The microstructures of the as-cast, pressed and heat-treated alloys were analyzed by scanning elec-tron microscope and transmission electron microscope. And the mechanical properties of the alloy in pressed and heat-treated states were studied. The results show that the ingots with diameter of 65 mm and external thickness about 5.5 mm are obtained when the temperatures of the melt in the internal and external ladles are 1 023 and 1 003 K, respectively, and the nozzle diameter is 2.0 mm. The microstructures of the as-cast alloy consist of α(AI) θ(CuAl2)q S(Al2CuMg) in the internal region and α(Al) MnAl6 in the external region. The phases found in the internal and external layers coexist in the transition zone. The transition layer is maintained after plastic deformation and heat treatment of the alloy. The tensile strength, yield strength and elongation of the alloy are 300 MPa,132 MPa and 16.0%, respectively, after T6 treatment. The tensile and yield strength are increased by 150.0% and 94.1%, respectively, compared with that of 3003 aluminum alloy. The maximum hardness in the internal region of 2024/3003 gradient aluminum alloy can be increased from HRF 55 in the pressed state to HRF 70 in the heat-treated state. 相似文献
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Warm compaction behaviors of iron-based powder lubricated by different kinds of graphite 总被引:1,自引:3,他引:1
1 INTRODUCTIONConventionalpowdermetallurgy(PM ) process ingcanproduceiron basedPM partswithadensitylessthan 7.1g/cm3(arelativedensityofapproxi mately 90 % ) .Theirmechanicalpropertiesaresub stantiallylessthanthoseoftheirfulldensitycounter part.IncreasingdensityisthebestwaytoincreasetheperformanceofthePM parts .Therearemanyprocessesthatcanproduceiron basedPM partswithhighdensitysuchaspowderforging ,doublepress/doublesinter(DP/DS)andCuinfiltration ,butwarmcompactionisthemosteconomical… 相似文献
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1 INTRODUCTIONWarm compaction is a relatively simple and e conomical process that can produce sintered partswith density up to 94% of the theoretical pore freedensity[1 3], and its potential is tremendous. Withminor modification on the conventional powdermetallurgy equipment and approximately 20%higher cost than conventional cold compaction,green compact density of 7.5 g/cm3 can be obtainedby single press. The only difference between thewarm compaction and th… 相似文献
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Regular elemental powders were used in warm flow compaction instead of the expensive micron-sized powders to fabricate cross-shaped parts. Debinding behaviors, sintering properties and shape consistency of the sintered parts were studied. Binder removal was accomplished by heating green compacts at intermediate temperatures with optimal heating rates until the debinding temperature was reached. Results show that by controlling debinding process, complex parts with good shape consistence can be obtained by warm compaction of binder-treated powder. Fine and shiny surface was obtained and no surface defect can be observed for sintered parts debinded at 2 ℃/min, while defect can be observed in sintered parts debinded at 4 ℃/min. 相似文献
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粉末冶金高致密化成形技术的新进展 总被引:13,自引:3,他引:13
本文针对粉末冶金行业近十年来出现的提高制品致密化的新途径新方法, 简要介绍了其中的温压技术,流动温压技术、模壁润滑技术、高速压制技术、动力磁性压制技术、爆炸压制技术、放电等离子烧结技术的原理、特点、发展和应用情况。指出发展粉末冶金高效高致密化成形技术是粉末冶金的发展方向和研究重点, 产品致密化程度的提高将大大促进性能的改进。粉末冶金新技术、新工艺、新材料的不断出现, 必将促进高技术产业的快速发展, 也必将带给材料工程和制造技术以光明的前景。 相似文献
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镁合金的发展动态和前景展望 总被引:18,自引:28,他引:18
在介绍镁合金的特点和研究概况的基础上,重点论述了镁合金材料和镁合金成形技术的发展动态,最后提出了镁合金发展的几个重要方向。 相似文献
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罗汇果倪东惠郑军君潘国如李元元 《材料工程》2009,(S1):139-141
以钛粉、硅粉和石墨粉为原料,通过无压烧结法制备了Ti3SiC2-SiC块体复合材料。利用X射线衍射仪对制得的样品进行相分析,并运用扫描电镜分析材料的微观结构,用差热分析仪测定反应温度。结果表明,Ti∶Si∶C=0.42∶0.23∶0.35时,可制得纯度较高的Ti3SiC2-SiC复合材料块体,只含有极少量的TiSi2杂质。Ti3SiC2晶粒无特定的生长方向,平均长度在10μm以下,厚度小于5μm。略高的Si含量有利于获得纯度较高的Ti3SiC2-SiC复合材料。 相似文献