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1.
Al2O3/TiC陶瓷—WC/Co硬质合金复合刀片的研制 总被引:1,自引:0,他引:1
采用热压烧结工艺制备了陶瓷-硬质合金复合刀片,其上层为具有一定厚度的Al2O3/TiC陶瓷材料下,下层为WC/Co硬质合金。分析表明:复合片中残余应力值的大小与其上下两层厚度之比h/H值有关。X射线衍射、电子探针和扫描电子显微镜分析表明:烧结过程硬质合金和陶瓷材料中的元素在界面存在相互扩散,增加了界面结合强度,其界面类型为扩散型。 相似文献
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Al2O3/TiB2陶瓷材料的高温摩擦磨损特性研究 总被引:4,自引:0,他引:4
研究了Al2O3/TiB2陶瓷材料与硬质合金往复滑动摩擦时,在不同氢气和温度条件下的摩擦磨损特性,结果表明:随温度和气氛不同,材料的摩擦系数有着不同的变化规律。在高温空气气氛中摩擦时,TiB2氧化生成的表面氧化膜可起到固体润滑剂的作用,并且能阻止Co的扩用,减轻粘着,因而能降低摩擦系数并有利于提高材料的耐磨性能;而在高温氮气气氛中摩擦时,由于硬质合金中的Cop扩散到陶瓷材料中,使材料产生粘着磨损和 相似文献
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采用不同常压烧结(CP)温度制备了Al2O3+WC复合陶瓷材料。利用扫描电镜(SEM)、X-射线衍射,能谱分析(EDAX)等手段和三点弯曲,单边切口梁等力学方法研究了该材料的组织结构、力学性能及增韧机制。结果表明,1600℃烧结Al2O3+WC陶瓷各相结合致密、分布均匀且晶普微细,其断裂形式为沿晶断裂,室温断裂强度为520MPa;断裂韧性为6.2MPa·m^1/2,第二相WC弥散分布细化了基本晶粒 相似文献
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以酚醛树脂为原料制备了炭支撑膜和炭-炭复合膜,研究了其气体分离性能。结果表明:炭支撑膜分离气体和机理包括努森扩散和粘性流;采用浸涂-干燥-炭化的工艺制备的炭-炭复合膜对H2/CO2具有较好的分离性能,H2/CO2分离系数达5.6,大于理想努森扩散的分离系数3.7。但在高压差时复合膜上CO2的表面扩散增强,使H2/CO2分离系数下降。 相似文献
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双受主掺杂BaTiO_3基PTC陶瓷性能的研究 总被引:1,自引:0,他引:1
本文系统地研究了Fe~(2+)、Mn~(4+)复合受主掺杂和烧结工艺对BaTiO_3基PTC陶瓷性能的影响, 通过不同复合受主掺杂量和不同烧结工艺,测试并整理了较大量的PTC陶瓷材料的室温电阻及 其升阻比数据,旨在研究多受主掺杂和烧结工艺对瓷料性能的影响规律及寻找一种相应的最佳配 方和最佳烧结工艺,提高PTC陶瓷的特性。 相似文献
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采用超声-放电复合加工技术对Al2O3/(W,Ti)C,Al2O3/TiB2,Al2O3/TiB2/SiCw三种Al2O3基陶瓷刀具材料表面定位方孔进行加工,研究了共加工机理和加工参数对不同陶瓷材料加工效率,加工表面粗糙度的影响,由于该复合加工技术有产地结合了超扬波加工和放电加工的特点,因而能高效,高质量地加工陶瓷材料。试验结果表明,在同样的加工条件下,材料去除率的大小顺序为Al2O3/(W,Ti 相似文献
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W18Cr4V钢表面激光熔覆Al2O3陶瓷涂层的组织结构 总被引:7,自引:0,他引:7
研究了W18Cr4V钢表面Al2O3/NiCrAl复合陶瓷涂层的组织结构、成分分布及界面组织特征。结果表明:Al2O3/NiCrAl复合陶瓷等离子喷涂层的组织呈层片状,面层由α-Al2O3和少量的γ-Al2O3组成,层间为机械结合界面,界面处成分变化梯度较大。经激光重熔后的面层组织为单一的α-Al2O3柱状晶,Al2O3与中间合金NiCrAl间存在明显的界面反应,且界面相增多,在NiCrAl与基体 相似文献
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《Diamond and Related Materials》2006,15(10):1643-1649
WC–Co nanocomposite powder produced by spray pyrolysis–continuous reduction and carbonization technology, diamond coated with tungsten (W) by vacuum vapor deposition and uncoated diamond were used in this study. This work adopted the spark plasma sintering (SPS) process to prepare diamond-enhanced ultrafine WC–Co cemented carbide composite material. The effects of W buffer on the stability of diamond with WC–Co nanocomposite powder during SPS were investigated. Results showed that the uncoated diamond was mechanically embedded in WC–Co cemented carbide matrix, while the diamond coated with tungsten was combined chemically with WC–Co cemented carbide matrix. Moreover, there was a transitional layer between the diamond and the matrix which could improve the thermal stability of the diamond, prevent carbon atom of the diamond from dissolving in Co phase and increase the bonding strength of the interface between the diamond and the matrix. 相似文献
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《Diamond and Related Materials》2000,9(2):191-194
Well-separated diamond particles were nucleated and grown by hot filament chemical vapor deposition (HFCVD) onto WC–Co cemented carbide pretreated by Murakami’s reagent and H2O2+H2SO4 solution. The adhesive strength of diamond particles to WC–Co cemented carbide was quantitatively determined in terms of interface toughness by directly applying an external load to the CVD diamond particles. From the measurement of the maximum load required to scratch off the particles, we determined that the adhesive toughness was 14 J/m2. This value is more than twice as high as that of CVD diamond on smooth silicon substrate and comparable to the cleavage fracture energy of diamond. The newly developed procedure will allow to check the effectiveness of substrate surface pretreatments for further improving the adhesion level of diamond films on WC–Co. 相似文献
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《Ceramics International》2021,47(18):26050-26062
In this study, the microstructure, mechanical properties, and cutting performance of WC-8Co cemented carbide with different Ru additions were studied in detail. The results show that Ru can inhibit the abnormal growth of WC grains and the mean grain size of WC grains decreases. Ru can result in the lattice distortion of Co phases and promote the phase transition of Co from face-centered cubic (FCC) to hexagonal closepacked (HCP) as Ru can reduce the stacking fault energy of Co phases. The proportion of HCP Co phases increased from 14.4 to 39.6% with increasing Ru content. Meanwhile, among the five groups of cemented carbides with different Ru additions, cemented carbides with 1.5 wt% Ru exhibit the highest hardness of 1382 HV and transverse rupture strength (TRS) of 3790 MPa. The enhanced hardness and TRS were due to solid solution strengthening and phase transition of Co, respectively. The fracture toughness of cemented carbide was enhanced from 16 MPa m−1/2 with 0 wt% Ru to 19 MPa m−1/2 with 0.5 wt% Ru. Additionally, during the dry cutting of Ti–6Al–4V, the diffusion of Ti and Al elements is hindered. Therefore, the wear resistance of the tools is improved. The cutting lifetime of the cemented carbide tools with 0.5 wt% Ru increased three-fold compared to those without Ru addition. 相似文献
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基于离心热爆反应、难熔液相分离与快速凝固原理,选取(WO3+Al+C)体系辅助(B4C+Ti)反应体系,采用自蔓延离心熔铸工艺可以成功制备出TiB2微纳米晶补强TiC-(Ti,W)C陶瓷基复合材料.将(B4C+Ti)、(WO3+Al+C)两种反应体系依次装填入坩埚中进行SHS离心熔铸实验,发现因W-Ti-C液相动力学粘度的降低、Al2O3液滴迁移路程减小,极大促进Al2O3液滴的Stokes上浮过程,故而显著减小残存于陶瓷基体上的氧化物夹杂含量与尺寸,进而TiB2微纳米片晶诱发的强烈自增韧机制与Al2O3微纳米晶产生的残余应力增韧效应,使得TiB2-(Ti,W)C-TiC陶瓷的弯曲强度、断裂韧性与维氏硬度分别达到(952±25)MPa、(12.6±2.5)MPa·m1/2与(28.6±1.2)GPa. 相似文献
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ANJIRAJU PERECHERLA WENDELL S. WILLIAMS 《Journal of the American Ceramic Society》1988,71(12):1130-1133
Measurements are reported of the room-temperature thermal conductivity of cemented multicarbides (WC-TiC x -NbC x -TaC x /Co) and straight tungsten carbide (WC/Co), which are widely used tool materials. The thermal conductivity of cemented titanium carbide was found to be lower than that of cemented tungsten carbide. The difference is attributed to strong phonon and electron scattering from carbon atom vacancies in the nonstoichiometric cubic carbide TiC x ; these defects are absent in stoichiometric hexagonal WC. Higher binder contents in tungsten carbide samples lowered the overall thermal conductivity. Scattering of electrons and phonons by C and W atoms in solid solution in the binder phase presumably reduces its thermal conductivity. No dependence on grain size was detected. 相似文献
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In this paper, CVD diamond coatings are deposited on cemented carbides with 10 wt.% Co using amorphous SiO2 and amorphous SiC interlayers. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Raman spectrum and X-ray diffraction (XRD) are carried out to characterize the microstructure and composition of as-deposited films. Moreover, the adhesion and cutting performance of as-fabricated diamond coatings are studied. Indentation tests show that the amorphous ceramic interlayers can enhance the adhesion between diamond films and WC–Co substrates. The cutting tests against zirconia indicate that the tools with amorphous ceramic interlayered diamond coatings exhibit improved cutting performance. The amorphous ceramic interlayers can improve the adhesive strength and wear endurance of diamond coatings on WC–10 wt.% Co substrates, which provide a viable way for adherent diamond coatings on cemented carbide tools with high cobalt content. 相似文献
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Shunlin Zhang Wuli Su Lan Sun Jun Wang 《International Journal of Applied Ceramic Technology》2023,20(3):1908-1918
In order to increase the toughness of WC–6Co cemented carbide, different contents of carbon nanotubes (CNTs) were added to the WC–6Co alloy powder to prepare cemented carbide by low-pressure sintering. The results showed that some of the CNTs were embedded between the grains of WC–6Co cemented carbide, which would hinder the growth of WC grain boundary, thus leading to grain refinement. In addition, CNTs inhibited the formation of decarbonized phase and guided the deflection and bridge of crack to hinder the crack extension. With the increase of CNTs content, the density increased at first and then decreased, and the transverse fracture strength increased at first and then decreased. When the content was 0.2 wt.%, the alloy had the best performance. The density of the alloy was 99.67%; the transverse fracture strength was up to 2937.5 MPa, which is about 100% higher than that of cemented carbide without CNTs. The fracture toughness was 9.84 MPa m1/2, and the hardness was 1924.8HV30. 相似文献