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铸铁件表面铸渗碳化钨颗粒的耐磨机理 总被引:6,自引:0,他引:6
测试了不同粒度碳化钨和基体材料的铸渗层的耐滑动磨损性能、抗磨料磨损性能和抗冲蚀性能,分析了不同磨损条件下铸渗碳化钨复合层的耐磨机理和失效方式,研究结果表明,铸渗碳化钨复合层在各种磨损条件下耐磨机理秩效方式不同,要根据不同使用条件合理2和制定碳化钨复全层的铸渗工艺。 相似文献
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工艺条件对WC/高铬铸铁铸渗效果的影响 总被引:2,自引:0,他引:2
高铬铸铁铸渗碳化钨制备的复合材料有利于解决特殊工况条件下零部件磨损异常突出的问题,但前提条件是要达到良好的铸渗效果。作者就浇注系统、浇注温度、型腔气压、铸渗层厚度等工艺参数对铸渗效果的影响进行了试验研究。结果表明,在适宜的铸造工艺条件下,碳化钨颗粒和高铬铸铁基体之间可以形成良好的冶金结合,铸渗效果较好。 相似文献
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碳化钨增强钢铁基耐磨复合材料的研究和应用 总被引:4,自引:0,他引:4
评述了制备复合材料的铸渗法、粉末烧结法、堆焊法、电渣熔铸法等工艺方法,以及碳化钨和钢铁基体的选择、界面反应和强度、复合材料的性能和应用现状.重点介绍了粘结剂、其他添加剂、碳化钨颗粒形状、粒度及其分布、浇注温度等对铸渗工艺及其表面复合材料的影响.阐明铸渗法是一种有前途的制备工艺,自蔓延工艺和铸造工艺的组合有可能取得新的成效.指出复合层厚度在10 mm以上的铸渗工艺,工程化和产业化关键技术以及复合工艺的稳定化是今后的研发重点,表面耐磨复合材料较适用于零部件的局部磨损和低角度的冲蚀磨损,应据磨损工况来选择制备工艺及其复合材料. 相似文献
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采用消失模铸渗工艺在ZG310-570表面制备了钒铬表面复合层,并考察了其显微组织和干滑动磨损性能.结果表明,所制备的复合层组织致密、无铸造缺陷.在铸渗复合层中存在着几种典型的碳化物形态:条块状、菊花状、短杆状以及团球状.在300~750 N载荷下,铸渗层的磨损量随载荷的增加而增加,当铸渗剂中铬铁、钒铁的质量分数分别为35%、40%时铸渗层的耐磨性能最好,在450 N载荷下是ZG310-570的16.5倍.铸渗层的磨损机理为磨粒磨损及塑性变形和剥落. 相似文献
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采用碳化钨和高碳铬铁作为主要渗剂,利用传统的铸渗工艺研究了渗剂成分对钨铬表面复合层组织的影响。结果表明:在ZG230-450铸件表面形成了一定厚度,与基体呈冶金结合的表面复合层;随碳化钨含量的增加,表面复合层中铬碳化物和钨碳化物的相对数量发生变化;随碳化钨和高碳铬铁含量的增加,表面复合层中铬碳化物的形态由断续网状转变为葵花状和条杆状。 相似文献
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采用铸渗技术,研究了在灰铸铁表面获得良好WC颗粒-高铬铸铁铸渗层工艺以及铸渗层组织和耐磨性。结果表明,在适宜工艺条件下,铸渗层平整,均匀,与在体结合良好,具有优良的抗磨粒磨损性能。用WC颗粒-高铬铸铁铸渗法制造的灰铸铁基搅拌机叶片,其使用寿命是Q235钢制叶片的三倍以上。 相似文献
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为在15CrMo钢表面采用等离子堆焊含60%WC的镍基合金粉末,对堆焊层的显微组织、硬度和高温耐磨性能进行了试验分析.结果表明,堆焊层焊道成形良好,堆焊层组织致密.堆焊层横截面上WC颗粒分布均匀,WC颗粒的质量分数可达60%以上,堆焊后WC颗粒硬度值基本上仍保持了原有的高硬度,颗粒表面重熔量小.堆焊层具有较高的硬度;原始WC颗粒构成的硬质骨架,加上次生WC的弥散强化作用,使堆焊层具有良好的耐磨料磨损性能,其600℃高温耐磨料磨损性能为45正火钢的5倍以上. 相似文献
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颗粒增强金属基复合材料耐浆料冲蚀磨损性能的研究 总被引:2,自引:2,他引:0
通过在碳化钨颗粒中加高碳铬铁颗粒的方式及负压铸渗方法,获得了碳化钨陶瓷颗粒体积分数不同的复合材料,考察了体积分数对在浆料冲蚀磨损条件下复合材料耐磨性的影响,结果表明,通过加高碳铬铁的方式,可使复合材料中的碳化钨颗粒体积分数从23%到56%之间变化,以51%的复合材料耐磨性最好,为镍硬1号的3.13倍。 相似文献
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预制块重熔法制备的SiC/Al复合材料的磨损性能研究 总被引:1,自引:0,他引:1
本文采用含高体积分数SiC颗粒预制体在高能超声搅拌下加入铝熔体的方法制备SiCP/Al复合材料,研究了复合材料的微观组织特征、硬度和摩擦磨损性能。实验结果表明:高能超声重熔预制块的方法制备的复合材料基体组织形态均匀细小,SiCP颗粒在复合材料中弥散分布,与基体间结合良好;随着SiCP颗粒体积分数的增加,复合材料的硬度上升,耐磨性显著提高。通过对复合材料磨损表面的SEM观察分析表明,在干摩擦条件下,复合材料的磨损机理为微切削磨损和表层剥落及部分粘着磨损的综合作用。 相似文献
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Tungsten carbide (WC)-reinforced Fe-based surface composites were prepared by in situ solid-phase diffusion at 1423 K for 4, 6, and 8 h. The thermodynamics, phase composition, microstructure, microhardness, and wear-resistance of the Fe–W–C ternary system of the samples were examined by X-ray diffraction, scanning electron microscopy, Vickers hardness test, and wear test, respectively. Thermodynamic calculations showed that the thermodynamically favored products of the Fe–W–C system were W2C, WC, and Fe3C. W also exhibited a stronger carbide-forming tendency than Fe. The Gibbs free-energies of W2C and WC, which were stable carbides, significantly decreased with increased temperature. The main phases of the composite were WC, γ-Fe, Fe3C, graphite, and η-carbide (M6C) with fishbone-like morphology. The longitudinal section of the composite could be easily divided into three reaction zones, namely, WC layer, “no graphite area,” and M6C-reinforced area. WC particles in the WC layer were irregularly shaped with 0.3–12 μm particle size, with volume fraction of up to > 80%. The average microhardness value of the dense ceramic layer was 2152 HV0.1. The maximum relative wear-resistance, which was 230.4 times higher than that of gray cast iron, was obtained at 20 N. The high wear-resistance of the composite was due to the in situ formation of dense and hard WC particulates that acted as a reinforcement phase. 相似文献
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In the present work we made and examined cemented carbides characterized by very different WC grain sizes varying from near-nano with a WC mean grain size of about 200 nm to coarse-grain with a WC mean grain size of about 4.5 μm and Co contents varying from 3 to 24 wt.%. The major objective of the present work was to examine the wear damage, wear behavior and wear mechanisms of cemented carbides having nearly the same hardness but greatly varying with respect to their WC grain size and Co content in the high-load ASTM B611 test and low-load G65 test.Both the hardness and resistance to fracture and micro-fatigue of cemented carbides play an important role in the wear damage by use of the high-stress ASTM B611 test when the carbide surface is subjected to alumina particles at high loads. In this case, the wear-resistance increases with increasing the WC mean grain size and decreasing the Co content at nearly the same hardness of the different cemented carbides. The submicron and near-nano cemented carbides are characterized by lower wear-resistance in comparison with the coarse-grain grade due to their reduced fracture toughness, fracture resistance and resistance to micro-fatigue.The Co mean free path in the carbide microstructure plays an important role with respect to wear-resistance in the low-stress ASTM G65 test when the carbide surface is subjected to gentle scratching by abrasive silica particles. The predominant wear of the thick Co interlayers leaving unsupported WC grains plays the decisive role in the wear behavior of the coarse-grain grade resulting in its low wear-resistance. In contrast to the ASTM B611 test the wear rate decreases with decreasing the WC mean grain size and increasing the Co content due to the corresponding reduction of Co mean free path in the carbide microstructure. As a result, the wear-resistance of the near-nano grade in the ASTM G65 test is the best of all in spite of its reduced fracture toughness.Phenomena of micro-fatigue, micro-fracturing and micro-chipping are found to play a decisive role in the wear damage of cemented carbides if they are subjected to abrasion wear, high loads and severe fatigue. 相似文献
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WC(27%) reinforced steel matrix composites were produced by using an electroslag melting casting technique. The microstructure of the material was characterized using scanning electron microscopy(SEM), optical microscopy and X-ray diffraction (XRD). Energy dispersive spectroscopy(EDS) and transmission electron microscopy were performed to investigate the interracial composition between WC particle and steel matrix. The results reveal that the WC particles are partially melted into the steel substrate. At the same time, a reaction layer was detected along with the periphery of WC particle, which significantly enhances the bonding strength of the interface. A slipping wear (high stress abrasion) test was utilized to understand the wear behavior of this material. Abrasive experiment displays a better wear resistance than unreinforced steel matrix when coarse WC particles are dispersed into it. The coarse particles provide greater wear-resistance than the fine particles and operatively takes on the most applied loads. Additionally, the large particles have not been peeled during the wear process for a long time, which indicates the effect of interfacial reaction on wear behavior at the ambient temperature. A double carbide (Fe, W)3C is detected in the interface zone between particles and matrices using transmission electron microscopy. 相似文献
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纳米结构WC/Co涂层是一种重要的纳米涂层材料,工程上对其的应用常常基于其高耐磨性和强抗腐蚀性。关干WC/Co涂层的精密磨削以及耐磨性能,已有学者对其进行丁一定的研究。对于其耐磨性能的研究主要是基于喷涂参数对它的影响;对于其磨削后耐磨性能以及磨削参数对耐磨性能的影响规律研究极少。本文综述了纳米结构WC/Co涂层制备方法、WC/Co涂层机械性能和摩擦磨损性能以及其精密加工等方面的研究现状,同时对陶瓷磨损预报做了简单的介绍。目的就是在后续的工作中对比研究磨削后纳米结构WC/Co涂层的耐磨性能以及并分析磨削参数对其耐磨性能的影响并建立预报模型。 相似文献