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热压烧结制备了Al2O3/Cr3C2/(W,Ti)C复合陶瓷材料(以下简称ACW复合材料),对其Vickers硬度及组织形貌进行了研究,分析了Cr3C2及(W,Ti)C对Vickers硬度的影响.结果表明,(W,Ti)C和Cr3C2的添加利于阻止晶界迁移,抑制晶粒长大,Cr、W、Ti离子在Al2O3基体晶粒中的固溶起强化作用.每一相的添加量在10%~20%(体积分数,下同)为宜,添加总量在30%左右ACW复合材料硬度最佳. 相似文献
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以Ti,Al,Tic,TiO2粉末为原料,采用原位热压合成法制备了Ti3AlC2/Al2O3复合材料.主要考察不同Al2O3含量对复合材料性能的影响.在1 400℃,30 MPa压力,保温2 h条件下烧结制得致密的Ti3Alc2/Al2O3块体材料.采用XRD分析了不同Al2O3,含量的复合材料的相组成.用SEM观察组织结构特征.测量了维氏硬度和电导率同Al2O3含量的关系曲线.研究结果表明,A12O3,的加入可大幅度提高复合材的硬度.Ti3AlC2/25%A12O3的维氏硬度可达8.7 GPa.虽然添加Al2O3后复合材料的电导率有所下降,但Al2O3对复合材料强度和硬度的增加有显著的贡献.Ti3Al2C2/Al2O3乃不失为一种性能良好的高温结材材料. 相似文献
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Ti/Al2O3复合材料性能研究 总被引:5,自引:0,他引:5
本文利用放电等离子烧结技术制备了致密的Ti/Al2O3复合材料.实验结果表明,60vol%Al2O3和80vol%Al2O3的Ti/Al2O3复合材料,界面处生成少量的TiAl,使得Ti与Al2O3间的界面能大于其单个晶粒的界面能,复合材料性能随Ti含量的增加而增大;40vol%Al2O3和20vol%Al2O3的Ti/Al2O3复合材料,界面处生成脆性的Ti3Al相,使得Ti与Al2O3间的界面能小于各自晶粒的界面能,材料的性能随Ti含量的增加而降低,同时断裂的模式也发生改变,由穿晶断裂为主转变为沿晶断裂,脆性的Ti3Al相是Ti/Al2O3复合材料力学性能降低的主要原因. 相似文献
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以铝热法为基础制备了A12O3/W复合材料,探讨了A12O3含量对复合材料合成的影响。研究表明:主要物相为α-A12O3、金属W。刚玉含量小于0.3时,温度影响不显著,大于0.3时,温度影响显著,有大量碳化物生成,且WC/W2C相对含量随A12O3含量增加及煅烧温度的提高而增加。当刚玉含量为0.5mol时,有正交晶钨酸铝生成。随刚玉含量变化,金属钨分布从连续分布向弥散分布变化。连续分布的金属钨因被氧化铝包裹因此难以碳化,而弥散分布的金属钨则易于被碳化。 相似文献
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研究了Ni和Ti的添加对真空热压烧结方法制备的Al2O3-Ti(C,N)陶瓷基复合材料的显微组织和力学性能的影响.发现添加Ni和Ti的复合材料主要由Al2O3、Ti(C,N)和Ni组成,没有发现存在金属Ti.Ti由于非常活泼,在热压烧结过程中可能与石墨模具产生的含C气氛反应生成TiC,或与高温下Ti(C,N)的少量分解产生的N2气氛反应生成TiN,这有利于减少复合材料中的气孔.适量添加Ni可通过液相烧结促进复合材料的致密化,提高复合材料的相对密度,并能通过产生裂纹偏转和裂纹桥联提高复合材料的断裂韧性.热压温度为1550℃、等摩尔比的Ni和Ti混合粉末添加量为5vol%时,Al2O3-Ti(C,N)-Ni-Ti复合材料的相对密度为99.6%,硬度为21GPa,抗弯强度为818MPa,断裂韧性为8.1 MPa.m1/2. 相似文献
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Al2O3/Ti3SiC2层状复合材料的制备与性能 总被引:4,自引:0,他引:4
采用两种方法制备Al2O3/Ti3SiC2层状复合材料,一是原位-热压法,即Ti3SiC2是在层状材料的制备过程中同时被合成的;一是分步法,即制备过程分两步进行,首先制备出Ti3SiC2高纯粉,再采用热压法进行烧结制备层状材料。两种方法制备的Al2O3/Ti3SiC2层状复合材料强度保持在450MPa以上,断裂功达到1200-1560J/m^2,相对Al2O3块体材料提高十余倍。另外,不同的制备方法得到不同的组成和显微结构,决定了这两种Al2O3/Ti3SiC2层状复合材料性能的差异:前者强度较高韧性较低,后者强度较低而韧性较高。 相似文献
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(Ti,V)2AlC/Al2O3 solid solution composites were prepared by solid state combustion simultaneously incorporating reduction reactions of V2O5 and TiO2/V2O5 with aluminum. Two reaction systems composed of Ti–V2O5–Al–Al4C3 and TiO2–V2O5–Al–Al4C3 powder mixtures were studied. Combustion exothermicity was enhanced by increasing V2O5 and Al, which not only caused an increase in the combustion temperature and reaction front velocity, but also facilitated evolution of the (Ti,V)2AlC phase. Between two reaction systems, the Ti-containing samples were more energetic and produced (Ti1–xVx)2AlC/Al2O3 composites with x = 0.2–0.8. The degree of element substitution was reduced for the samples adopting TiO2, which yielded Al2O3-added (Ti1–yVy)2AlC with y = 0.4–0.8. 相似文献
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SiC晶须和Ti(C,N)颗粒协同增韧Al2O3陶瓷刀具的研究 总被引:3,自引:0,他引:3
采用热压工艺烧结制备了SiCW-Ti(C,N)-Al2O3(Y2O3)陶瓷刀具复合材料.研究了不同烧结温度(1600~1750℃)下,材料的致密度和力学性能(断裂韧性KIC,维氏硬度HV和抗弯强度σf)随晶须含量(10%~40%)的变化关系;探讨了SiC晶须和Ti(C,N)颗粒对Al2O3基体的协同增韧机理.同时与SiCW-Al2O3陶瓷及Ti(C,N)-Al2O3陶瓷作对比研究.结果表明:SiCW-Ti(C,N)-Al2O3(Y2O3)陶瓷材料在1750℃,晶须含量为20%时获得最佳的综合力学性能:KIC=7.11 MPa.m1/2,HV=21.16GPa,σf=820MPa;明显高于SiCW含量为20%的SiCW-Al2O3陶瓷和不加晶须的Ti(C,N)-Al2O3陶瓷.第三相Ti(C,N)颗粒的加入与晶须一起产生明显的迭加增韧效果,而且对SiCW的各种增韧机制起到了促进作用. 相似文献
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M. Zarezadeh Mehrizi R. Beygi Gh. Eisaabadi B M. Velashjerdi F. Nematzadeh 《Advanced Powder Technology》2019,30(2):311-316
Ti3AlC2/Al2O3 nanocomposite powder was synthesized by mechanical-activation-assisted combustion synthesis of TiO2, Al and C powder mixtures. The effect of mechanical activation time of 3TiO2-5Al-2C powder mixtures, via high energy planetary milling (up to 20?h), on the phase transformation after combustion synthesis was experimentally investigated. X-ray diffraction (XRD) was used to characterize as-milled and thermally treated powder mixtures. The morphology and microstructure of as-fabricated products were also studied by scanning electron microscopy (SEM) and field-emission gun electron microscopy (FESEM). The experimental results showed that mechanical activation via ball-milling increased the initial extra energy of TiO2-Al-C powder mixtures, which is needed to enhance the reactivity of powder mixture and make it possible to ignite and sustain the combustion reaction to form Ti3AlC2/Al2O3 nanocomposite. TiC, AlTi and Al2O3 intermediate phases were formed when the initial 10?h milled powder mixtures were thermally treated. The desired Ti3AlC2/Al2O3 nanocomposite was synthesized after thermal treatment of 20?h milled powder and consequent combustion synthesis and FESEM result confirmed that produced powder had nanocrystalline structure. 相似文献
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Wetting behavior and interface interaction between Y2O3 and Cu–alloys were investigated at 1,423 K. Pure copper does not wet yttria substrate but the wettability is significantly
improved by additions of Al and Ti. Different interface structures were observed in the Y2O3/(Cu–Al) and Y2O3/(Cu–Ti) systems. Relatively deep crater was detected at the interface in the first system, while Cu alloying by Ti led to
formation of a flat interface with a thin reaction layer. The results of the wetting experiments and the interface features
were well accounted of by thermodynamic analysis of the Y2O3/(Cu–Me) systems. 相似文献