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烧结法制备金属多孔材料 总被引:2,自引:0,他引:2
烧结金属多孔材料兼具金属材料和多孔材料的特性,近年来受到广泛关注,在很多领域都得到应用.本文重点阐述烧结金属多孔材料的传统制备技术及特种制备技术.传统的制备技术主要分为固态烧结法、半固态烧结法、粉体熔化法.特种烧结技术包括激光选区烧结技术、放电等离子烧结技术等. 相似文献
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钛酸铋钠(BNT)基压电材料因具有较好的电学性能以及高居里温度等优点,成为了压电材料领域的研究热点之一。如何制备出性能优异的钛酸铋钠基压电材料,是满足各个领域应用要求的重要环节。重点综述了近年来钛酸铋钠基压电材料制备技术的研究进展,从固相烧结、放电等离子烧结以及微波烧结等角度对其烧结技术进行论述;从溶胶-凝胶、脉冲激光沉积和射频磁控溅射等角度对其薄膜制备技术进行综述;对热喷涂制备压电涂层的机理和工艺进行总结。结果表明,烧结温度是影响块体材料结构和性能的关键因素,其中放电等离子烧结与微波烧结相较于传统的固相烧结能够有效控制材料的烧结温度;在钛酸铋钠薄膜的制备中对沉积温度、氧气压力以及退火温度的控制可以有效提高薄膜电学性能;热喷涂制备的钛酸铋钠涂层通过热处理工艺能够改善涂层的电学性能,并且热喷涂能够在复杂零件表面实现压电涂层的可控制备,其中钛酸铋钠压电陶瓷薄膜和涂层的制备扩展了其应用范围。最后,展望了压电陶瓷材料技术的未来发展趋势,为压电材料制备技术的研究提供了一定的参考。 相似文献
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介绍了微波烧结技术的原理及特点,简要概括了目前制备特种陶瓷的研究现状,并对微波烧结陶瓷材料、硬质合金(WC-Co)、微波烧结金刚石烧结体等问题进行了分析讨论,初步探讨了微波烧结技术在超硬材料制品中广泛应用的可能性。 相似文献
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超细WC-Co硬质合金复合粉末的研究进展 总被引:1,自引:2,他引:1
超细硬质合金因其高强度、高硬度、高耐磨性等优良性能满足了现代工业的发展,而制备超细WC-Co硬质合金关键技术之一在于原料粉末的制备。近年来,研究人员开发了多种超细WC-Co复合粉末的制备技术,有利于制备出具有超细结构的WC-Co合金材料。本文介绍、归纳了目前国内外直接还原碳化法、化学沉淀法、机械合金化法、喷雾转化法的制备超细WC-Co复合粉末工艺及研究成果,其中喷雾干燥法和直接还原碳化法已在硬质合金行业中实现部分产业化,具有诱人的应用前景。 相似文献
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Zinc Reclaimed WC-Co powder exhibits faceted WC crystal shape while virgin WC-Co powder can have rounded WC particles. During sintering, the WC grains in Zinc Reclaimed WC-Co powder remain faceted while virgin WC-Co retains its rounded WC shape until the later stages of sintering. The effect of the shape of WC grains in Zinc Reclaimed WC-Co on its densification behavior is not fully understood. The effect of WC crystal shape on the densification of Zinc Reclaimed WC-Co during sintering is investigated. The shrinkage of Zinc Reclaimed WC-Co is measured by dilatometry and found to lag behind the shrinkage of virgin WC-Co after the first densification stage during solid state sintering. There is a greater lag in the shrinkage of coarse grained Zinc Reclaimed WC-Co than fine grained Zinc Reclaimed WC-Co relative to the corresponding virgin WC-Co. The role of packing density on the densification of Zinc Reclaimed WC-Co during solid state sintering is discussed. 相似文献
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通过分析放电等离子烧结致密化过程,确定了致密化温度;研究了SPS烧结过程中压力对WC-Co硬质合金致密化、显微组织及性能的影响。结果表明,放电等离子烧结粉末在1 130℃时,达到最大收缩率;烧结压力的增加,样品的致密度、硬度增加;断裂韧性的变化集中在11.5~12.1 MPa.m1/2之间,和硬度的变化呈现相反的趋势;烧结压力相对较小时,样品WC晶粒较粗大且不均匀;在40 MPa和55 MPa时,晶粒相对较小且分布均匀。要得到高性能、高致密度的样品,合理的烧结温度在1 200℃以上,烧结压力为40 MPa。 相似文献
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The influence of Cr3C2 doping on the sintering process and mechanical properties of WC-Co cemented carbides was studied. Using differential thermal analysis of green powders and thermodynamic calculations, the disappearing temperature of solid-state binder phase in the ultra-fine WC-Co cemented carbides with different amounts of Cr3C2 dopant was first investigated and then verified to descend with the increase of Cr content. Based on these investigations, the sintering temperatures of three alloys with 0.3, 0.5 and 0.65 wt% Cr were selected to high by 50 °C than the phase disappearing temperature of solid-state binder. Compared with the commercial sample with the sintering temperature at 1410 °C for Cr3C2 doped WC-Co cemented carbides, the optimized sintering temperatures lead to finer microstructures and better mechanical properties, such as transverse rupture strength and hardness. In addition, the reliability for the performance of WC-Co cemented carbides prepared with the optimized sintering schedule is significantly improved in comparison with the commercial sample. The strategy from the present work can be used to design sintering process parameters during the manufacture of ultrafine WC-Co cemented carbides. 相似文献
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Hwan-Cheol Kim In-Jin Shon Jin-Kook Yoon Jung-Mann Doh 《Metals and Materials International》2006,12(2):141-146
The sintering behavior and mechanical properties of WC-Co and WC-Ni hard materials produced by high-frequency induction-heating
sintering (HFIHS) were compared using ultra fine WC, WC-Co, and WC-Ni powders. HFIHS allows very quick densification to near
theoretical density and prohibits grain growth in nano-structured materials. Highly dense WC, WC-Co, and WC-Ni with a relative
density of up to 99.2% could be obtained with simultaneous application of 60 MPa pressure and induced current within 2 min
without significant change in grain size. The hardness and fracture toughness of the dense WC, WC-Co, and WC-Ni composites
produced by HFIHS were also investigated. 相似文献
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超细WC-Co硬质合金的制备与性能研究 总被引:5,自引:4,他引:1
利用高能球磨法制备纳米级WC-Co混合粉末,采用脉冲电流烧结技术进行烧结。用能谱分析仪(EDX)对球磨后的粉末进行成分分析,用X射线衍射(XRD)对比分析球磨前后WC-Co混合粉末的衍射峰变化,用透射电子显微镜(TEM)和扫描电子显微镜(SEM)对所制备的粉末及烧结材料进行了组织形貌观察,并测定了烧结试样的硬度。结果表明:随着球磨时间的延长,WC-Co纳米粉末的粒度逐渐变小,当球磨时间超过30h后获得了粒度为100nm以下的WC-Co纳米粉末。脉冲电流烧结后获得超细WC-Co硬质合金,与传统的WC-Co硬质合金相比,超细WC-Co硬质合金具有更高的硬度(HRA92.5~94)和耐磨性。另外通过实验获得了最佳的烧结工艺参数。 相似文献
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金刚石增强稀土纳米硬质合金复合齿研究 总被引:1,自引:0,他引:1
以液相复合—连续还原碳化方法制备的纳米复合WC-Co粉末、共沉淀法制备的Ni-Ce粉末和真空蒸镀W膜金刚石为原料,采用热压活化烧结,在1050℃的烧结温度、70MPa烧结压力、保温(3~5)min烧结条件下,制取了具有良好抗冲击性能和耐磨性的金刚石增强稀土纳米硬质合金复合齿。复合齿基体的维氏硬度HV1≥1800,抗弯强度TRS≥2800MPa,合金晶粒度在(200~400)nm之间,复合齿超硬部分的磨耗比≥80。结果表明共沉淀法制备的Ni-Ce粉末显著降低了合金中微孔和杂质等组织缺陷,大大提高了金刚石增强纳米硬质合金复合齿的整体性能。 相似文献