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碳化钨/铁基铸造复合材料的抗冲蚀磨损性能 总被引:19,自引:1,他引:18
采用真空负压工艺获取碳化钨颗粒增强铁基表面复合材料,分析复合层微观经组织结构,并模拟实际工况考察复合层的抗浆料冲蚀磨损性能。结果表明,碳化钨颗粒增强铁基表面复合材料具有良好的组织结构和优异的抗冲蚀磨损性能,与高铬铸铁相比其抗冲蚀性是高铬铸铁的3 ̄4倍。 相似文献
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采用灰铸铁(HT300)与厚度为0.25 mm的钛板,通过浇注法使得灰铸铁与钛板紧密结合,在真空管式炉中1 138℃保温时间8 h后,等温处理并炉冷.通过观察,在基体表面原位生成了TiC颗粒增强铁基表面梯度复合材料,对梯度复合区进行显微组织观察、显微硬度测量以及磨损性能测试.结果表明,TiC颗粒增强表面梯度复合材料大致分为三层,各层之间最大的区别是:生成的TiC颗粒的大小及形状不相同;从复合层(C区)到珠光体区显微硬度逐渐降低,显微硬度最大的区域出现在致密陶瓷层(C区).因此对TiC颗粒增强表面梯度复合材料致密陶瓷层进行了磨粒磨损试验,表明陶瓷层耐磨性比灰铸铁(HT300)有了很大程度上的提高. 相似文献
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《材料热处理学报》2015,(10)
采用铸渗—热处理法将纯铬板与TH300进行原位反应制备了(Fe,Cr)7C3/Fe表面复合材料。应用XRD、SEM和显微硬度计对不同保温时间所得的表面复合材料进行物相、显微组织和显微硬度进行了分析。结果表明:随着保温时间的增加,显微组织逐渐由网状的(Fe,Cr)3C型碳化物逐渐转变为颗粒状和板条状的(Fe,Cr)7C3型碳化物。当1185℃保温2 h后在铬板与基体结合处生成了整块状致密(Fe,Cr)7C3陶瓷层,其体积分数达90%以上,当1185℃保温4 h后整块状致密(Fe,Cr)7C3陶瓷层消失。(Fe,Cr)7C3/Fe表面复合材料的显微硬度值为1478 HV0.1,约是灰铸铁基体微硬度的5倍。 相似文献
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通过TIG电弧直接加热方式实现Ag-Cu-Ti钎料在C/C复合材料上的润湿,观察不同保温时间下润湿钎料宏观形貌,并利用SEM和EDS研究接头微观组织和元素分布. 结果表明,在一定保温时间下钎料发生软化,当保温时间为60 min时,钎料在C/C复合材料上润湿效果最好,TiC反应层分布最均匀致密,厚度约为1.3 μm,扩散层厚度最大为5.5 μm. 在向反应界面接近的过程中,钎料中Cu和Ag的含量和保持不变,并有AgTi/CuTi3/Cu4Ti3等脆性化合物的生成. 此外,Ti元素在近界面处发生聚集,在聚集区有Ti2Cu生成. 相似文献
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对Al-Ti-C体系进行热力学分析,在氩气保护下进行热爆反应试验.采用铸造反应合成技术在铸铁表面原位合成TiC/Al3Ti复合材料.研究热爆产物及表面复合材料的物相、组织和界面形貌,并对其形成机理进行探讨.结果表明:采用热爆工艺使Al-Ti-C体系发生反应,生成纯净的TiC/Al3Ti复合产物.在熔融铁液作用下,Al-Ti-C体系反应完全,制备出纯净的TiC颗粒增强金属间化合物基表面复合材料.表面复合材料组织致密,与铁基体界面为良好的冶金结合.当TiC含量较少时,颗粒呈条状;随着TiC含量的提高,颗粒尺寸逐渐减小,由长条状向粒状及细粒状转化. 相似文献
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氩气保护下碳化钨对镍基合金熔覆层组织及耐磨性的影响 总被引:3,自引:3,他引:0
目的改善Q235钢板的耐磨性,以取代65Mn在振动筛筛板中的应用。方法采用电阻丝加热非真空熔覆技术,在氩气保护条件下于Q235钢表面制备碳化钨/镍基合金复合熔覆层。通过SEM和XRD观察分析熔覆层与基体的结合方式、碳化钨分布、熔覆层组织及相组成,通过硬度测试及磨损试验,分析碳化钨对熔覆层耐磨性的影响。结果熔覆层与钢基体达到冶金结合。熔覆层主要由奥氏体、碳化钨、碳化物及硼碳复合化合物等相组成,碳化钨弥散分布其中。当碳化钨用量为熔覆粉末总质量的35%时,熔覆层硬度为47.3HRC,磨损率为0.08 mg/m,约是钢基体耐磨性的5倍,65Mn耐磨性的4倍。结论采用氩气保护制备的碳化钨熔覆层与基体结合良好,提高了钢基体的耐磨性。 相似文献
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A new method is presented for the fast preparation of functionally graded cemented carbide materials by microwave heating nitriding sintering. The influence of composition and sintering temperature on the mechanical properties, microstructure, and phase composition of the materials was studied. Results showed that functionally graded cemented carbides with the desired mechanical properties can be obtained rapidly by microwave heating nitriding sintering. A gradient layer with a Ti(C, N)-enriched surface layer, and underneath a Co-enriched layer formed on the top of the hard alloy substrate. The nitriding process had little effect on the microstructure of the matrix. A lower surface roughness, and the similar layer thickness as seen in conventional heating nitriding was obtained by microwave heating nitriding sintering in a short period of time. The thickness of the gradient layer increased with increasing temperature. The high Ti content in the raw material was beneficial to the formation of the gradient layer; however, the Co content had little effect on the gradient layer thickness when it increased from 6% to 10%. 相似文献
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采用无压浸渗工艺制备了铸造碳化钨颗粒增强PDC钻头胎体材料,胎体材料组织均匀,胎体中碳化钨颗粒完整,碳化钨颗粒与铜合金基体形成均匀扩散层。重点研究了PDC钻头胎体的三体磨料磨损行为和磨损机理。结果表明:铸造碳化钨颗粒形貌是影响PDC钻头胎体三体磨料磨损行为的主要因素。相对于破碎铸造碳化钨,球形碳化钨内部微裂纹少且无应力集中,具有耐磨增效作用,可显著提高PDC钻头胎体材料的三体磨损性能。球形碳化钨颗粒增强PDC钻头胎体的相对耐磨性是破碎碳化钨颗粒增强PDC钻头胎体的10倍。破碎碳化钨颗粒增强PDC钻头胎体的磨损表面呈现大量铜合金基体犁沟,多角状碳化钨颗粒被磨损变圆滑;而球形碳化钨颗粒增强PDC钻头胎体的磨损表面碳化钨颗粒突出林立,少量碳化钨颗粒被折断或发生破裂。 相似文献
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在自研制的碳化钨管状药芯焊条中添加不同含量的钒元素(0%~3%)并制备堆焊合金,通过SEM,XRD,EDS等研究分析手段,研究不同钒含量对碳化钨耐磨层组织性能的影响规律.结果表明,钒含量与堆焊层中碳化钨颗粒的溶解程度密切相关,钒优先将碳化钨颗粒分解出的碳原子以碳化钒形式固定,从而抑制了碳化钨颗粒的分解,钒元素含量决定了碳化钨溶解的强弱,含有2%钒元素的堆焊层中生成适量碳化钒有效抑制了碳化钨的溶解.钒元素的加入还能强化碳化钨堆焊层基体金属的硬度,降低堆焊层中碳化钨颗粒剥落的风险,有效提高了堆焊层的耐磨性. 相似文献
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目的提升低温钢的摩擦磨损性能,为极地特殊船板的焊补和延寿技术提供试验依据。方法利用等离子转移弧技术,在低温钢E32表面堆焊制备3组球形不同碳化钨含量的钴基涂层,比较该改性涂层和E32钢在低温条件下(–20℃)的摩擦磨损性能。通过X射线衍射仪、扫描电子显微镜、能谱分析仪、3D光学轮廓仪等研究手段,分析碳化钨含量对堆焊层耐磨损性能和显微组织的影响规律,并揭示其耐磨损机理。结果在载荷为50 N、滑动速度为20 mm/s条件下,经2 h干滑动摩擦磨损后,3组涂层较低温钢E32的摩擦系数和体积磨损率均下降,磨痕的宽度和深度均变小。富含WC、W2C增强相以及Cr23C6、Cr7C3、Co6W6C和Fe6W6C等碳化物硬质相的涂层,显著提升了E32钢的硬度和低温耐磨性。涂层的低温耐磨性能随着碳化钨含量的增大而提高,未添加碳化钨的涂层的主要磨损机理为磨粒磨损和粘着磨损,当碳化钨的质量分数为30%和60%时,主要磨损机理为三体磨粒磨损。结论通过在E32钢表面进行等离子转移弧堆焊,得到了结构致密、高硬度和抗低温耐磨性的球形碳化钨增强钴基表面改性涂层,在一定程度上提升了低温钢的服役寿命。 相似文献
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A. K. Jha Arati Gachake B. K. Prasad Rupa Dasgupta M. Singh A. H. Yegneswaran 《Journal of Materials Engineering and Performance》2002,11(1):37-45
Steel surfaces were thermally sprayed with nickel chromium boron (NCB) powder (with and without tungsten carbide) using an
oxy-acetylene torch. The sprayed (hard) surfaces and substrate were characterized for abrasive wear properties. Test parameters
such as load and sliding distance were varied. A significant improvement in the abrasive wear resistance (inverse of wear
rate) was noted for the thermally sprayed surfaces as compared to that of the substrate. Wear surfaces, subsurface regions,
and debris were examined in order to ascertain the operating wear mechanisms. Substrate (mild steel), because of its low hardness,
suffered severe wear through the cutting, ploughing, and wedging action of the hard abrasive (silicon carbide). Deep cuts
on the worn surface, a bulky transfer layer, subsurface cracks, and large-size debris were observed. However, wear was reduced
due to high hardness of the layer of NCB powder on the substrate, which resisted the penetration of abrasive into the surface.
Presence of tungsten carbide in the layer of NCB powder further reduced the wear of the corresponding specimen because of
very high hardness of the tungsten carbide. Shallow wear grooves and finer debris were observed for the NCB coating with and
without tungsten carbide. Cutting was the predominating wear mechanism in the case of coatings. 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