TZP／TiC／Al2O3陶瓷复合材料在模具中的应用

采用ＴＺＰ相变和ＴｉＣ颗粒共同增韧Ａｌ２Ｏ３，使ＴＺＰ／ＴｉＣ／Ａｌ２Ｏ３复合材料的抗弯强度σｆ和断裂韧度ＫＩＣ分别达到１１０６ＭＰａ和１１．８６ＭＰａ·ｍ＾１／２。探讨了复合材料在用作螺旋丝拉拔模具时的磨损和破损行为，研究了ＴＺＰ和ＴｉＣ对模具磨损和破损性能的影响。     

复合软质过渡层对钛纤维增强Ti—Al基复合材料性能的影响

研究了复合软质过渡层对钛纤维增强Ｔｉ－Ａｌ基复合材料界面和性能的影响。结果表明，在增强体与基体间增加复合软质过渡层Ｙ２Ｏ３－Ｃｒ等的钛纤维增强Ｔｉ－Ａｌ基复合材料，其界面有Ｔｉ３Ａｌ、Ｔｉ２Ａｌ、Ｔｉ２Ｃｕ及β相产生，界面结合完整。复合界面的弯曲强度达７０９ＭＰａ，较涂覆单一Ｙ２Ｏ３的钛纤维增强Ｔｉ－Ａｌ基复合材料提高２６％，弯曲挠度提高较小。增加复合软质过渡层有利于钛纤维增强Ｔｉ－Ａｌ基复合材料     

复合软质过渡层对钛纤维增强Ti－Al基复合材料性能的影响

研究了复合软质过渡层对钛纤维增强Ｔｉ－Ａｌ基复合材料界面和性能的影响。结果表明，在增强体与基体间增加复合软质过渡层Ｙ２Ｏ３－Ｃｒ等的钛纤维增强Ｔｉ－Ａｌ基复合材料，其界面有Ｔｉ３Ａｌ、Ｔｉ２Ａｌ、Ｔｉ２Ｃｕ及β相产生，界面结合完整。复合界面的弯曲强度达７０９ＭＰａ，较涂覆单一Ｙ２Ｏ３的钛纤维增强Ｔｉ－Ａｌ基复合材料提高２６％，弯曲挠度提高较小。增加复合软质过渡层有利于钛纤维增强Ｔｉ－Ａｌ基复合材料的强韧化     

自蔓延高温合成Al2O3＋ZrO2＋Cr复合材料

自蔓延高温合成是制备材料的一种新工艺。通过热力学和显微结构分析研究了Ａｌ－Ｃｒ２Ｏ３－ＺｒＯ２系统，结果表明：在Ａｌ：Ｃｒ２Ｏ３：ＺｒＯ２＝１：２．８：１．４３（ｗｔ）时，可以自蔓延高温合成Ａｌ２Ｏ３－ＺｒＯ２－Ｃｒ复合材料，ＺｒＯ２不与Ａｌ发生反应，产物孔隙度达３５％－４５％。     

SiCw／ZTA（Y）陶瓷基复合材料力学性能的研究

研究了不同ＳｉＣ晶须含量对ＺＴＡ（Ｙ）陶瓷基复合材料力学性能的影响，实验结果表明，ＳｉＣ晶须能明显提高复合材料的抗弯强度和断裂韧性，晶须含量为２０ｖｏｌ％时，复合材料性能可达σｂｂ＝３８０ＭＰａ，ＫＩＣ＝９．８ＭＰａ·ｍ＾１／２，但晶须含量过高时，复合材料的强度有下降趋势。     

热压工艺参数对纳米SiC—Al2O3／TiC新型陶瓷刀具材料力学性？…

研究了压力、热压温度和保温时间等工艺因素对纳米ＳｉＣ－Ａｌ２Ｏ３／ＴｉＣ系新型陶瓷刀具材料的抗弯强度、韧性和硬度的影响。结果表明,对于纳米ＳｉＣ－Ａｌ２Ｏ３／ＴｉＣ系陶瓷复合材料,在压力为３０ＭＰａ热压温度为１７００℃,保温时间为６０ｍｉｎ时,材料的性能最好。     

添加Cu元素对Al／Al2O3复合材料力学性能的影响

探讨了热压烧结制备Ａｌ／Ａｌ２Ｏ３复合材料的可能性。用ＳＥＭ和ＸＲＤ分析了添加５％Ｃｕ后复合材料界面的组织结构和相组成，研究了铜对材料硬度和耐磨性的影响，研究表明，Ｃｕ元素的加入可以明显提高复合材料的力学性能，同时可以使Ａｌ２Ｏ３的加入量显著提高。     

Al／TiC复合材料中TiC合成的研究

研究了利用反应合成法制备Ａｌ／ＴｉＣ复合材料的反应过程，温度特性，以及钛粉粒度对它的影响。讨论了反应合成的反应机理。通过ＳＥＭ观察了Ａｌ／ＴｉＣ复合材料中ＴｉＣ的微观组织结构。结果表明，可以利用纯组元的反应合成制备Ａｌ／ＴｉＣ复合材料，制得的复合材料的增强相具有尺寸细小（０．１￣１μｍ）、分布均匀的特点。钛粉粒度对反应过程的温度特性有较大的影响，但对生成相组成及ＴｉＣ形貌没有影响。     

非调质塑料模具钢中易切削相的分析

运用光学显微镜、扫描电镜、电子探针以及图像分析仪，分析了Ｓ、Ｓ－ＲＥ、Ｓ－Ｃａ－ＲＥ非调质塑料模具钢中易切削相的形貌、分布、组成及其对力学性能的影响。结果表明，经Ｃａ、ＲＥ处理的钢中，出现以ｍＣａＯ·ｎＡｌ２Ｏ３为核心的ＭｎＳ和ＣａＯ·Ａｌ２Ｏ３·ＴｉＮ·（Ｍｎ，Ｃａ）Ｓ·ＲＥ２Ｓ３组成的复合硫化物，多呈纺锤形，提高了钢的横向冲击韧性，另外采用适量的铝和微量的钛也有利于改善易切削相形态     

用于微波器件的大面积YBCO超导薄膜

高质量大面积ＹＢＣＯ薄膜是用原位中空柱状阴极直流磁控溅射装置制备的，化学计量比的超导靶的内为１００ｍｍ，加热器有效面积５０×４０ｍｍ＾２。在３０×３０ｍｍ＾２的Ｚｒ（Ｙ）Ｏ２ＬａＡｌＯ３基片上沉积的ＹＢＣＯ薄膜的厚度均匀度为±６％，临界温度Ｔｃ＞８９Ｋ，Ｔｃ不均匀性在１％以上，△Ｔｃ在０．８～０．９之间，临界电流密度Ｊｃ为２．０～３．５×１０＾６Ａ／ｃｍ＾２，△Ｊｃ为１．０～１．５Ａ／ｃｍ＾２，微     

Mechanical Behaviors of ZrO2-Al2O3 Ceramic Composites with Y2O3 as Stabilizer

Forlongthebrittlenessofceramicmaterialshasstoodinthewayofindustrialapplicationanddevelop ment.However ,inrecentyears ,suchprogressasthephasetransformationtougheningofzirconia ,thedis persionofparticletougheningandthefiberorwhiskertougheninghavewellimprove…     

Al2O3含量对ZrO2/Al2O3陶瓷材料微观结构和力学性能的影响

以陶瓷纺织剪刀为应用目标。开发成功ZrO2／Al2O3复相陶瓷材料，并对其微观结构和力学性能进行了研究。结果表明。随着Al2O3含量的增加，材料晶粒逐渐减小，材料中t相ZrO2的含量呈上升趋势。这有利于材料断裂韧度和横向断裂强度的提高；当Al2O3含量（质量分数）为20％左右时，ZrCh／Al2O3复相陶瓷材料的综合力学性能最佳。     

Transformation Behavior and Mechanical Properties of Al2O3/ZrO2(2Y) Ceramic Composites

The content of zirconia has a remarkable influerce on transformation behavior and mechanical properties of Al2O3/ZrO2 (2Y) composites. When 15% and 20% ZrO2(2Y) was added to Al2O3, the bending strength and fracture of the content of ZrO2 (2Y) on transformation and mechanical properties was investigated. The changes of m-ZrO2 and t-ZrO2 phases content before and after fracture were measured by X-ray diffraction quantitative phase analysis, It is shown that improvement in bending strength and fracture toughness of the Al2O3/ ZrO2 (2Y) composites is due to the phase transformation toughening mechanism of ZrO2 (2Y) and thermal expansion mismatch.     

Physicochemical Processes of Fabricating Ceramic Materials Based on Nanopowders of Zirconium,Yttrium, Cerium,and Aluminum Oxides

When studying nanoceramics, it is necessary to constantly keep in mind the closest interrelation of their fabrication method, structure, and properties. Nanoceramic materials are used in various branches of technology as structural and functional materials. Nanoceramics are also widely used in medicine. They are harmless, stable, and have great affinity to living organisms. ZrO2-based nanoceramics have a lower elastic modulus than other oxide materials. The specificity of their application lies in their high rupture strength, thermal shock resistance, and chemical stability at high temperatures. However, it is necessary to solve the problem of increasing the fracture toughness of ZrO2-based ceramic materials. The complex alloying of ZrO2 with yttrium and cerium oxides and the use of the Al2O3 additive leads to an increase in the fracture toughness and lowering of the negative effect of materials in the biological medium. In this work, the physicochemical properties of ceramic powders and materials of the ZrO2–2Y2O3–4CeO2–Al2O3 system synthesized by the chemical deposition of inorganic precursors when applying the sol-gel technology are considered based on scientific data and experimental studies. Alloying pure zirconium oxide by stabilizing Y2O3 and CeO2 oxides and thermal hardening of Al2O3 ensure the conservation of the tetragonal structure at room temperature, which makes it possible to retard and control the crack resistance of the material under the load. Investigations into the influence of the sintering temperature and aluminum oxide content on the microstructure and grain size, as well as physicomechanical properties of ceramic materials of compositions ZrO2–2Y2O3–4CeO2 + 1 wt % Al2O3 and ZrO2–2Y2O3–4CeO2 + 3 wt % Al2O3, are carried out.     

高能球磨制备WC/Al2O3-Cr-Mo-Ni金属陶瓷及其组织和力学性能

以亚微米级WC粉、Al2O3粉、Cr粉、Mo粉与Ni粉为原料,采用高能球磨+热压工艺制备WC/Al2O3-Cr-Mo-Ni金属陶瓷材料,利用X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)分析材料的物相组成和显微组织结构以及断裂方式,研究粘结相Ni和陶瓷相Al2O3的含量(均为质量分数)对该材料力学性能和微观结构的影响。研究表明:金属陶瓷的抗弯强度及断裂韧性随Ni含量增加而提高,随Al2O3含量增加而降低,硬度的变化趋势则相反。当Ni含量为7%、Al2O3含量为10%时,该金属陶瓷具有良好的综合性能,抗弯强度为567 MPa,断裂韧性为7.46(MPa.m1/2),维氏硬度为15.24 GPa,基本达到现用模具材料的水平。随着Ni含量增加,金属陶瓷的断裂方式由沿晶断裂向沿晶断裂与穿晶断裂相混合的方式转变。     

铝锆碳滑板材料在钙处理钢液中的侵蚀行为

 采用旋转抗渣法研究了试样转速、钙处理钢液温度对铝锆碳材料在钙处理钢液中平均溶解速率的影响,结果发现铝锆碳材料的平均溶解速率随转速的增大而增大,它在钙处理钢液中的溶解过程不与扩散控制过程类似;铝锆碳材料的平均溶解速率随钙处理钢液温度的提高而迅速增加。铝锆碳材料的侵蚀机理为钙处理钢液中CaO侵入铝锆碳试样内部,使得试样中Al2O3、SiO2与之发生反应,形成低熔物,低熔物进入钢液中导致溶损。     

添加ZrO2对Si3N4复合陶瓷材料力学性能的影响

通过无压烧结制备了ZrO2-Si3N4复合陶瓷材料,并以排水法、SEM和DDL100型万能拉伸机进行表征。研究了ZrO2含量对Si3N4陶瓷的致密度、显微结构和力学性能的影响。结果表明,随着ZrO2含量的增加,Si3N4陶瓷致密度增加;抗弯强度和断裂韧性先增大后减小,当ZrO2含量达到10%时,Si3N4的抗弯强度和断裂韧性同时达到最大值,分别为362MPa和7.0MPa.m1/2。ZrO2增韧Si3N4陶瓷的机制为应力诱导相变。     

坩埚材质及顶渣成分对帘线钢夹杂物成分的影响

 使用碳管炉熔炼帘线钢72A,研究不同材质坩埚及不同成分顶渣对钢中夹杂物的影响。结果表明,MgO坩埚冶炼的帘线钢中夹杂物变形率高于ZrO2、SiO2、Al2O3坩埚。采用SiO2坩埚冶炼时,钢中夹杂物几乎不变形,其SiO2含量大于90%(质量分数,下同)。采用Al2O3坩埚,个别夹杂物Al2O3的含量达到40%左右,不适合冶炼帘线钢。钢中夹杂物成分进入较低熔点区(即不大于1500℃的区域)的条件为：采用MgO坩埚,顶渣碱度为10时,wAl2O3≤3%,或顶渣碱度为09时,wAl2O3为9%;采用ZrO2坩埚时,顶渣碱度为11~12时,wAl2O3为3%。     

Effect of Y2O3 and Sm2O3 on Sintering and Mechanical Behaviors of Alumina Ceramics

The effects of Y2O3 and Sm2O3 doping on the sintering temperature, microstructure and mechanical behaviors of Al2O3 ceramics were investigated. The experimental results show that the sintering temperature can be decreased and the mechanical behavior can be improved by adding rare earth in alumina ceramics. The relative density of rare-earthdoped alumina ceramics reaches 98.8% after sintering at 1600 ℃ for 2 h, and its bending strength and fracture toughness reach 439 MPa and 5.28 MPa·m1/2,respectively.Introduction of Y2O3 and Sm2O3 in Al2O3 can restrain the growth of grains, refine the size of grains, and thus form a fine-grained structure. The fracture characteristic is the mixed modes of intergranular and transgranular fracture.     

氧化铝基氧化物/氧化物复合材料的合成与评价

Al2O3 matrix oxide/oxide composites containing rod-like Ba-β-Al2O3 and equiaxed ZrO2 particles have been successfully synthesized by an in-situ process from a mixture of Al2O3 and BaZrO3 powders.The long-axis direction of rod-like Ba-β-Al2O3 phase is parallel to ,while the longitudinal interface between Ba-β-Al2O3 phase and Al2O3 matrix is parallel to(0001) of the Ba-β-Al2O3 phase.The mechanical properties of the composites,such as Vickers hardness and fracture toughness,are enhanced with increasing the sintering temperature.Furthermore,the presence of rod-like Ba-β-Al2O3 particles results in enhancement of fracture toughness of the in-situ synthesized composites due to crack deflection and crack bridging.