共查询到18条相似文献，搜索用时 171 毫秒
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研究了Y-TZP/α-Al2O3复相陶瓷的凝胶注模成型工艺,着重研究了低粘度高固相体积分数浓悬浮体的制备.利用自制分散剂PA对Y-TZP、a-Al2O3进行表面吸附修饰改性,通过PA对两种颗粒的电空间稳定机制,在pH=9.5及最佳分散剂用量条件下制得低粘度高固相量的Y-TZP/α-Al2O3复相陶瓷悬浮体. 相似文献
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本文采用掺杂Cr2C3的方法探究增韧补强反应烧结SiC陶瓷的途径。通过凝胶注模成型及反应烧结工艺制备Cr/Si/C复相陶瓷由SiC、Si和CrSi2组成,CrSi2由Cr2C3与熔融Si反应生成;材料中SiC颗粒分布均匀,CrSi2存在明显偏析;Gr/Si/C复相陶瓷抗弯强度接近反应烧结SiC/Si陶瓷,平面应变断裂韧性KIC达到3.81MPa.m1/2;CrSi2分布不均和弱化界面结合是抗弯强度以及弹性模量降低的原因。 相似文献
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研究了Y-TZP/α-Al2O3复相陶瓷,在低粘度高固相体积分数浓悬浮体时的凝胶注模成型制备工艺.利用自制分散剂PA对Y-TZP、α-Al2O3进行表面吸附修饰改性,通过PA对两种颗粒的电空间稳定机制,在pH=9.5及最佳分散剂用量条件下制得低粘度高固相量的Y—TZP/α—Al2O3复相陶瓷悬浮体. 相似文献
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探讨了粒径分布较宽的粗颗粒氧化锆粉末的分散性、浆料的流变性和稳定性及其凝胶注模成型。实验结果表明,选用适量的分散荆柠檬酸铵,调整pH在8.6-10.5之间,可制备出流动性较好的固相含量高达63Vol.％的ZrO2浆料,沉降实验表明一定体积百分数的浆料的稳定性较好,悬浮粒子不会发生沉降,凝胶注模成型出的形状复杂的氧化锆湿坯体性能良好,均匀致密。 相似文献
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粗颗粒氧化锆粉体凝胶注模成型工艺研究 总被引：4，自引：0，他引：4
探讨了粒径分布较宽的粗颗粒氧化锆粉末的分散性、浆料的流变性和稳定性及其凝胶注模成型。实验结果表明，选用适量的分散剂柠檬酸铵，调整pH在8．6—10．5之间，可制备出流动性较好的固相含量高达63Vol.％的ZrO2浆科，沉降实验表明一定体积百分数的浆料的稳定性较好，悬浮粒子不会发生沉降，凝胶注模成型出的形状复杂的氧化锆湿坯体性能良好，均匀致密。 相似文献
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采用高分散、高稳定混合水悬浮液方法制备Si3 N4/ [SiC +B4C]复合陶瓷 ,研究了亚微米B4C含量对Si3 N4/ [SiC+B4C]复合陶瓷性能的影响以及断裂相变量与性能的关系 ,讨论了B4C应力诱导相变增韧机制与微米粒子强韧化机制迭加的可能性 相似文献
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粉末注射成型(PIM)技术的出现,使得零件的生产成本大大降低,同时零件的形状也趋于复杂化。其生产工艺由制备粉末和喂料、注射成型、脱脂和烧结四步骤构成。PIM技术是利用金属或陶瓷粉末结合先进的注射成型工艺来生产净形金属或陶瓷微型零件的方法。本文分析了A l2O3粉末制备的微型零件,并展示了尺寸为喂料粒子尺寸10倍的零件。目前,利用PIM技术,已成功制备出了结构尺寸为5μm的零件。PIM技术不但能够生产多种具有热、磁、光、电等功能性金属和陶瓷制品,同时也为大批量生产微型零件开辟了通道 相似文献
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以α-SiC和BaAl2Si2O8（BAS）为原料,采用热压烧结工艺制备了SiC基复合材料．研究了添加剂对液相烧结SiC基复合材料的致密化、显微组织、抗弯强度及断裂行为的影响．测试结果表明,添加剂BAS有效促进了SiC基复合材料的致密化．40wt％BAS／SiC复合材料的抗弯强度和断裂韧性分别高达454MPa和5．1MPa·m^1/2．复合材料的主要增韧机制为SiC晶粒的拔出、裂纹偏转和裂纹桥连． 相似文献
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INTRODUCTION In powder compaction, the characteristics ofthe powder affect the compaction behavior and thequality of the pressed green body and its relativedensity, porosity, pore size distribution, sinteringand the consequent microstructure of the final sin-tered body. Superfine powder is prerequisite forpreparing high performance ceramic materials (Liu,1996; Lange et al., 1983; Lange, 1989). At present,most of the chemosynthesis methods are not suit-able for preparing industrial … 相似文献
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Silicon carbide ceramics were prepared with SiC powder treated by the fluidized bed opposed jet mill as rawmaterials, and the effects of the ultra-fine treatment mechanism on the compaction and sintering behavior of SiC ceramicswere investigated. The results showed that the compacts had higher density and microstructure homogeneity when thesintering temperature of the compact was decreased; and that the surface microstructure, densification and mechanicalproperties of the sintered body could be ameliorated obviously. 相似文献
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Silicon carbide (SiC) composites were prepared by hot-press sintering from α-SiC starting powders with BaAl2Si2O8 (BAS). The effects of additives on densification, microstructure, flexural strength, and fracture behavior of the liquid phase sintered (LPS) SiC composites were investigated. The results show that the served BAS effectively promotes the densification of SiC composites. The flexural strength and fracture toughness of the SiC composites can reach a maximum value of 454 MPa and 5.1 MPa·m1/2, respectively, for 40% (w/w) BAS/SiC composites. SiC grain pullout, crack deflection, and crack bridging were main toughening mechanisms for the sintered composites. 相似文献
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Siliconcarbide (SiC)ceramicmaterialsareusefulad vancedmaterialsinmanyfields,suchasmedicalbiomateri als ,hightemperaturesemiconductors ,synchrotronopticalel ementsandhighstrength /lightweightstructuralmaterials[1] .However,theactualapplicationisstilllimitedduetoitslowreliability ,highmachiningcosts[2 ] .Gelcastingprovidesane conomicalandfeasiblenet shape forminghomogeneousandflawlessgreenbodieswithcomplexgreenshapes. Gelcastingconsistsofin situpolymerizationthroughwhichamacromolecularnetwor… 相似文献
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Amorphous SiBCNAl powders were prepared via a mechanical alloying (MA) technique using crystalline silicon (Si), hexagonal boron nitride (h-BN), graphite (C), and aluminum (Al) as starting materials. SiBCNAl powders were consolidated by a hot pressing (HP) technique at 1800 °C under a pressure of 30 MPa in argon and nitrogen. The sintering atmosphere had a great influence on the microstructures and mechanical properties of the ceramics. The two ceramics had different phase compositions and fracture surface morphologies. For the ceramics sintered in argon, flexural strength, fracture toughness, elastic modulus and Vickers hardness were 421.90 MPa, 3.40 MPa·m1/2, 174.10 GPa, and 12.74 GPa, respectively. For the ceramics sintered in nitrogen, the mechanical properties increased, except for the Vickers hardness, and the values of the above properties were 526.80 MPa, 5.25 MPa·m1/2, 222.10 GPa, and 11.63 GPa, respectively. 相似文献
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采用自蔓延高温合成方法,以Ti、Si、C粉为原料合成了层状Ti3SiC2陶瓷材料,用X射线衍射分析了燃烧合成产物的相组成,并结合反应物体系的差热分析和X射线衍射分析探讨了自蔓延高温合成Ti3SiC2的相形成过程,进而建立Ti-C-Si体系在自蔓延燃烧合成反应过程的物理模型. 相似文献
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Silicon carbide (SIC) ceramic with YAG (Y3Al5O12) additive added by sol-gel method was liquid-phase sintered at different sintering temperatures, and the sintering mechanism and microstructural characteristics of resulting silicon carbide ceramics were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and elemental distribution of surface (EDS). YAG (yttrium aluminum garnet) phase formed before the sintering and its uniform distribution in the SiC/YAG composite powder decreased the sintering temperature and improved the densification of SiC ceramic. The suitable sintering temperature was 1860 ℃ with the specimen sintered at this temperature having superior sintering and mechanical properties, smaller crystal size and fewer microstructure defects. Three characteristics of improved toughness of SiC ceramic with YAG added by sol-gel method were microstructural densification, main-crack deflection and crystal ‘bridging‘. 相似文献