共查询到19条相似文献,搜索用时 109 毫秒
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采用铸渗和热处理原位反应工艺相结合的方法,将准1 mm的钒丝与灰铸铁进行复合,制成钒丝-灰铸铁复合预制体,并对其进行热处理,使钒丝中的钒原子与铸铁中的碳原子原位反应生成V8C7颗粒,制备出V8C7颗粒增强铁基复合材料。用SEM、XRD对该复合材料的显微组织和物相组成进行分析。结果表明,生成的V8C7颗粒均匀分布于铁基体中,且生成物与基体有很好的冶金结合,反应区主要由α-Fe和V8C7颗粒组成;应用热力学原理对原位合成V8C7颗粒的反应机理进行分析,表明用此方法制备的V8C7增强相在热力学上是可行的。 相似文献
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《热加工工艺》2021,(18)
为了提高铁基合金表面的强度,采用了一种原位反应工艺制备了碳化钒(V2C和V8C7)陶瓷增强铁基体表面复合材料。通过X射线衍射(XRD),扫描电子显微镜(SEM),电子背散射衍射(EBSD)分别研究了该复合层的显微组织和相组成。结果表明,钒板中的钒原子和铁基体中的碳原子在高温下通过相互扩散在结合面处发生原位反应,形成了致密的碳化钒陶瓷层,该层物相主要由V2C和V8C7组成。除此之外,采用压痕测试评估了金属陶瓷层的显微硬度、弹性模量和断裂韧性。所得结果表明,其断裂韧性值在0.426~1.136 MPa·m1/2范围内,且碳化钒陶瓷层的显微硬度为9.67GPa,是基体硬度的2~3倍。 相似文献
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铸铁与钛丝原位反应的研究 总被引:3,自引:3,他引:0
采用1138℃下保温2h方法,让提前置于铸铁中的钛丝与周围碳原子原位反应生成TiC增强铸铁复合材料,对复合区进行显微组织观察分析、显微硬度测量、耐磨性能测试。结果表明,复合区硬度最高达3182HV0.05,平均硬度是基体的12~15倍。复合材料的耐磨性相对于铸铁标准试样提高了3.22倍。 相似文献
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《铸造技术》2019,(10):1035-1038
采用原位反应与两步法热处理结合方法,使铌丝提供的铌原子与灰口铸铁中石墨提供的碳原子发生原位自生反应,制备了NbC增强铁基复合材料。采用XRD、SEM、TEM等检测手段对复合材料的物相组成与组织结构进行分析,利用显微硬度计对复合材料进行硬度与显微压痕形貌及压痕裂纹分析。结果表明,通过原位反应成功制备了NbC增强铁基复合材料,该复合材料的主要物相组成为α-Fe、Nb、NbC、G。NbC/Fe陶瓷层的厚度约为242±3μm,NbC/Fe陶瓷层与Nb丝、铁基体之间呈现良好的冶金结合。NbC陶瓷颗粒形貌为标准的立方体,NbC/Fe陶瓷层的显微硬度是铁基体的3~4倍。 相似文献
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研究用钒丝作为增强相的原材料,利用钒丝与高碳钢中碳原子原位反应,制备碳化钒-高碳钢复合材料。结果表明,试验制备得到了V8C7硬质相,颗粒大小范围约为4~9μm,均匀分布的颗粒有利于提高复合材料的组织稳定性。在本试验条件下,复合材料的耐磨性是高碳钢标准试样的4.17倍。 相似文献
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试验研究钛丝与铸铁原位反应制备复合材料.采用氩气保护、1 138 ℃进行2 h的等温处理并炉冷,对复合区进行显微组织观察、显微硬度测量、耐磨性能测试.结果表明,埋入铸铁内的钛丝反应生成了TiC增强相,复合区硬度较基体有了显著的提高;相对于铸铁标准试样,复合材料的耐磨性能有了明显的改善. 相似文献
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本文研究了在三体磨损条件下,WC颗粒增强Cr系白口铸铁表层复合材料的三体磨损性能;并与相应的Cr系白口铸铁的三体磨损性能进行了比较.结果表明,铸态去应力处理时,Cr系白口铸铁随着金属Cr含量的增加,其耐磨性有所增强.Cr含量从2%增加到26%,相对耐磨性从1增加到1.39,而复合材料相对于基体材料的耐磨性提高到了6以上;硬化态去应力处理时,Cr系白口铸铁随着金属Cr含量的增加,其耐磨性略有增强.Cr含量从2%增加到26%,相对耐磨性从1增加到1.29,而复合材料相对于基体材料的耐磨性提高到5以上.可见,为了提高Cr系白口铸铁材料表层的耐磨性能,采用WC颗粒增强Cr系抗磨白口铸铁表层复合材料的途径十分有效. 相似文献
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系统研究了在三体磨损条件下,WC颗粒增强Cr系白口铸铁表层复合材料的抗磨损性能,并与相应的Cr系白口铸铁的抗磨损性能进行了比较.结果表明,铸态去应力处理时,Cr系白口铸铁随着金属Cr含量的增加,其耐磨性有所增强;Cr含量从2%增加到26%,相对耐磨性从1增加到1.39,而复合材料相对于基体材料的耐磨性提高到了6以上.硬化态去应力处理时,Cr系白口铸铁随着金属Cr含量的增加,其耐磨性略有增强;Cr含量从2%增加到26%,相对耐磨性从1增加到1.29,而复合材料相对于基体材料的耐磨性提高到5以上.可见,为了提高Cr系白口铸铁材料表层的耐磨性能,采用制备WC颗粒增强Cr系抗磨白口铸铁表层复合材料的途径十分有效. 相似文献
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Libin Niu Mirabbos HojamberdievYunhua Xu 《Journal of Materials Processing Technology》2010,210(14):1986-1990
An iron-based composite reinforced by in situ-formed tungsten carbide particles was fabricated on gray cast iron substrate by a centrifugal casting process. The as-prepared composite was characterized by X-ray diffraction, scanning electron microscopy, and microhardness and wear testers. An appropriate pouring temperature (1300 °C) of the gray cast iron melt was chosen considering the dissolution temperature of the tungsten wires determined by differential scanning calorimetry. The experimental results showed that the tungsten wires were dissolved partially by the cast iron melt. As a result, primary and secondary tungsten carbide particles and pearlite with a negligible amount of graphite flakes were formed as the reinforcing phase and the matrix, respectively. The composite with a thickness of about 3 mm was dense and metallurgically bonded to the gray cast iron substrate. Wear resistance was determined by a pin-on-disc wear test technique, indicating that the composite containing high volume fraction of hard tungsten carbides presented higher wear resistance compared with the unreinforced gray cast iron. 相似文献
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《稀有金属(英文版)》2017,(12)
By adding mixture of ZrO_2 and carbon, a Zrenhanced composite coating was produced onto an AISI1045 substrate by laser cladding. The microstructure and phase formation, microhardness and wear resistance of the composite coating were studied. The experimental results indicate that the composite coating with metallurgical bonding to substrate consists of y-Ni, massive ceramic particles of ZrC,NiZr_2, Ni_7 Zr_2,(Fe,Ni)_(23)C_6 and Fe_3 C. The in situ-synthesized ZrC particles are uniformly dispersed in composite coating, which refines the microstructure of composite coating. With different Zr02 and carbon additions, the properties are improved differently. Finally, the fine in situ ZrC particles improve the microhardness of composite coating to HV_(0.2) 650, which is nearly 2.7 times that of Ni25 coating. Also, the composite coating has an advantage in wear resistance; it offers better wear resistance when more mixture of ZrO_2 and carbon was added in nickel alloys. 相似文献
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采用等离子熔覆技术,以铸造碳化钨、钨铁粉、镍包石墨和铁基合金粉为原材料,在Q235钢基体上制备了外加和内生联合WC颗粒增强铁基复合涂层,通过扫描电镜和能谱分析、X射线衍射、硬度测试和磨料磨损试验对其微观组织、物相组成、硬度和耐磨性能进行了表征。结果表明,在优化的工艺参数下,可以获得与基体冶金结合良好的涂层,硬质相除外加的WC颗粒,还有内生的WC、W2C、W3C、Fe3W3C和Fe2W2C等;随着混合粉末中除外加WC之外的W含量增加,熔池中合金液密度增大,可以减弱外加WC颗粒下沉;当W含量达到15%时,外加WC颗粒均匀分布在涂层中,没有团聚现象发生,且在外加WC颗粒周围有细小的原位WC颗粒生成,涂层的显微硬度和耐磨损性能显著提高,涂层的平均硬度约为1300 HV0.2,耐磨性为Q235钢基体的10倍。 相似文献
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Fangxia Ye Mirabbos Hojamberdiev Yunhua Xu Lisheng Zhong Honghua Yan Zhe Chen 《Journal of Materials Engineering and Performance》2014,23(4):1402-1407
The V8C7 particulates-reinforced iron-based metal matrix composite with 8-33 vol.% V8C7 was produced by infiltration casting process with subsequent heat treatment at 1164 °C for 3 h. With increasing the volume fraction of V8C7 in the composite, microhardness of the composite increases, while its impact toughness decreases. Relative wear resistance of the composite with different volume fractions of V8C7 was also investigated in this study. The composite with 24 vol.% V8C7 shows the highest relative wear resistance, which is much higher than that of gray cast iron. Microcracking, microploughing, and the fragmentation of particulates are found to be the dominant wear mechanisms. 相似文献