Y-TZP增韧陶瓷的制备及力学性能

研究了制备工艺和Ｙ２Ｏ３含量对四方多晶氧化锆（ＹＴＺＰ）力学性能的影响，并研究了３ＹＴＺＰ陶瓷的断裂统计、耐热冲击特性。２．５ＹＴＺＰ和３ＹＴＺＰ陶瓷的三点抗弯强度分别为１３６０±１６８ＭＰａ和１０８１±２４３ＭＰａ，Ｗｅｉｂｕｌ模数ｍ分别为８．２７和４．３４；断裂韧性分别为１１．７９ＭＰａ·ｍ１／２和１１．６０ＭＰａ·ｍ１／２。ＹＴＺＰ陶瓷中ＺｒＯ２以四方相与少量的立方相形式存在；压痕裂纹扩展为沿晶和穿晶混合模式。     

铝锆复合材料的增韧机理

在氧化铝陶瓷基质中,四方氧化锆（ｔＺｒＯ２）转变为单斜锆（ｍＺｒＯ２）,同时颗粒周围产生微裂纹,故复合材料的增韧机理主要为相变增韧和微裂纹增韧。为了测定这两种增韧作用的大小,进行了如下的实验：试样配比为８５Ａｌ２Ｏ３·１５ＺｒＯ２,分别加入不同量的纯ＺｒＯ２、Ｙ２Ｏ３部分稳定ＺｒＯ２及ＭｏＯ２部分稳定ＺｒＯ２,在３０ＭＰａ下热压成型,１４００～１５００℃,１ｈ,通Ｎ２条件下烧成,制成含ｍＺｒＯ２１０％、４５％和６７％的试样。实验结果表明：含纯ＺｒＯ２的合成料断裂韧性最高,Ｙ２Ｏ３部分稳定Ｚ…     

GPSZrO_2-Si_3N_4复合材料性能的研究

本文研究了ＧＰＳＺｒＯ２－Ｓｉ３Ｎ４复合材料的烧结性能、相组成、显微结构和力学性能。ＺｒＯ２－Ｓｉ３Ｎ４复合材料在１７７０～１８００℃,氮气压力分别为１ＭＰａ,２ＭＰａ,３ＭＰａ下烧成,获得相对密度＞９５％烧结体。实验结果表明：少量的工业ＺｒＯ２对氮化硅有助烧作用,增大氮气压力有利于改善氮化硅陶瓷材料的烧结性能和力学性能;ＺｒＯ２可提高氮化硅基体的断裂韧性,在３ＭＰａ下烧成条件下,添加１５％ＺｒＯ２的Ｓｉ３Ｎ４复合材料断裂韧性可达８．０８ＭＰａ．ｍ１／２,与基体相比提高２１．５％,第二相粒子增韧和微裂纹增韧为主要增韧机理。     

化学共沉淀法制备微晶PSZ陶瓷的显微结构与力学性能

采用化学共沉淀法制备ＺｒＯ２－ＭｇＯ－Ｙ２Ｏ３系和ＺｒＯ２－ＭｇＯ－Ｙ２Ｏ３系均匀超细活性粉末，经化学组成和显微结构设计，获得了固溶湿度小于等于１５５０℃且致密烧结的微晶ＰＳＺ复相陶瓷，其常温抗弯强度为７６６ＭＰａ，断裂韧性Ｋ１ｃ为１２．５ＭＰａ·ｍ＾１／２。研究了ＭｇＯ和Ａｌ２Ｏ３以及１１００℃热处理时间对材料显微结构、相组成和力学性能的影响。     

SiCw增韧Al2O3／TiB2陶瓷复合材料的研究

根据对晶须与基体材料的热胀失配的分析，计算得出了Ａｌ２Ｏ３／ＴｉＢ２／ＳｉＣｗ三元复合材料中ＳｉＣｗ的临界体积分数。采用ＴｉＢ２颗粒增韧和ＳｉＣｗ增韧两种途径来改善Ａｌ２Ｏ３的脆性，得到此复合材料的抗弯强度为７４０ＭＰａ，断裂韧性为７．７ＭＰａ·ｍ＾１／２。分析表明：当ＳｉＣｗ含量大于临界体积分数时，强度大幅降低的主要原因是由于致密度的降低和热残余拉应力的增大。     

KSZP陶瓷的烧结和力学性能

研究了ＫＺｒ２Ｐ３（ＫＺＰ）－ＳｒＺｒ４Ｐ６Ｏ２４（ＳＺＰ）系统陶瓷（ＫＳＺＰ）的显微结构和力学性能，添加ＭｇＯ作为烧结助剂，使材料力学性能得到显著的改善，抗弯强度达到１２３ＭＰａ，断裂韧性为２．１ＭＰａ．ｍ＾１／２弹性模量达１１０ＧＰａ，Ｖｉｃｋｅｒｓ硬度为４．５ＧＰａ。     

Si_3N_4－ZrO_2陶瓷中ZrN的生成及其对性能的影响

研究了ＺｒＮ在Ｓｉ＿３Ｎ＿４－ＺｒＯ＿２复相陶瓷中的形成及其对材料性能的影响，结果表明：在１．５ＭＰａＮ２气压烧结条件下，ＺｒＮ的形成温度约为１６００℃，提高Ｎ＿２的压力有利于抑制ＺｒＮ的生成，以稳定的ｔ－ＺｒＯ＿２加Ｓｉ＿３Ｎ＿４基体中，对抑制ＺｒＮ的生成有明显作用。当复相陶瓷中生成一定量的ＺｒＮ时，力学性能明显下降，而ＺｒＯ＿２分布均匀且以ｔ－ＺｒＯ＿２，ｃ－ＺｒＯ＿２形式存在时，复相陶瓷具有较高的强度（７４０ＭＰａ）和断裂韧性（８．８ＭＰａ·ｍ￣（１／２））。     

巴基管/纳米SiC陶瓷材料的研究

本文研究了巴基管／纳米ＳｉＣ陶瓷材料。初步讨论了在热压条件下,巴基管、烧结温度和添加剂对其机械性能的影响。结果表明,添加了巴基管后,纳米ＳｉＣ的抗弯强度（室温）和断裂韧性有所提高。优化的工艺方案是在ＳｉＣ中添加１０ｗｔ％的巴基管、１ｗｔ％的Ｂ４Ｃ,烧结温度２０００℃（保温１ｈ,压力２５ＭＰａ）;其性能达到：相对密度９４．７％、抗弯强度（室温）３２１．２２ＭＰａ、断裂韧性３．８２ＭＰａ·ｍ＾１／２。     

添加剂Y_2O_3对Mg-PSZ显微结构及力学性能的影响

研究了添加Ｙ２Ｏ３对ＭｇＰＳＺ显微结构及力学性能的影响。结果表明,ＭｇＰＳＺ中引入Ｙ２Ｏ３有利于降低烧结温度,促进立方化完全,但烧结体的力学性能有所降低。在１４００℃下热处理,（Ｍｇ,Ｙ）ＰＳＺ材料与ＭｇＰＳＺ一样发生ｃＺｒＯ２→ｔＺｒＯ２的析出过程,析出纺锤状四方ＺｒＯ２晶体。１４００℃热处理１０ｈ获得最大抗弯强度达６４８ＭＰａ,断裂韧性Ｋ１ｃ为８．３ＭＰａ·ｍ１／２。Ｙ２Ｏ３的加入使获得优异力学性能的热处理范围变宽,因而工艺上容易控制。但Ｙ２Ｏ３加入过多使析出困难。最佳加入量为１．０％（摩尔百分数）。Ｙ２Ｏ３的加入还使材料的Ｗｅｉｂｕｌ模数增高至１８．４６,表明（Ｍｇ,Ｙ）ＰＳＺ经热处理后能消除内部缺陷,使材料可靠性提高。     

SiC_p－AlN复合材料力学性能及增韧机理研究

本研究表明ＳｉＣ颗粒尺寸及含量对ＳｉＣ_ｐ－ＡｌＮ复合材料力学性能有较大影响。通过工艺因素的控制，ＳｉＣ_ｐ－ＡｌＮ复合材料的抗弯强度可达５６９ＭＰａ，断裂韧性可达５．１４ＭＰａ·ｍ~（１／２）。另外，对复合材料的显微结构进行了观察，并分析了其增韧机理。     

Effects of Additives on Structure and Properties of Synthesized Cordierite

Cordierite was synthesized using fly ash,sintered magnesia and silica fume as starting materials,ZrO2 and CaF2as additives,drying at(110 ± 5) ℃ for 24 h,and then firing at 1 290 ℃ for 3 h. Effects of type and addition of additives on structure and properties of synthesized cordierite were researched. The compressive strength, water absorption and apparent porosity,shrinkage rate,and bulk density of the specimens were measured,the phase composition was analyzed by XRD,and the specimens were observed by SEM. The results show that:(1) cordierite can be successfully synthesized using fly ash,sintered magnesia and silica fume;(2)CaF2facilitates the sintering,enhancing bulk density and shrinkage rate, but reducing the compressive strength; ZrO2 can promote cordierite synthesis,compacting the structure and increasing the compressive strength;(3) when the ZrO2 addition is 2 mass%,the main crystal phases are hexagonal α-cordierite and orthorhombic β-cordierite,the crystals grow well,and the amount of synthesized cordierite is the highest.     

Spherulitic Growth from a Phase-Separated Vitreous Matrix in a Cordierite–Y-Stabilized Zirconia Glass-Ceramic

Crystallization behavior, especially spherulitic growth of a cordierite–3 mol% Y₂O₃–ZrO₂ glass composition annealed at 950° to 1370°C was studied by optical and electron microscopy. Microstructural analysis revealed that glass-inglass phase separation occurred prior to the crystallization of β-quartz solid solution ( ss ). ZrO₂ was involved in promoting the nucleation of β-quartz ss ; the crystallization evolved from a cellular to a spherulitic morphology, and β-quartz transformed to α-cordierite as the temperature was raised. ZrO₂ was eventually expelled intergranularly and intragranularly to form slightly misoriented domains upon annealing, and the dendritic or clustered tetragonal t -ZrO₂ crystals transformed to monoclinic ( m ) in symmetry. A possible dragging force exerted between α-cordierite and a glassy droplet phase is proposed to explain the corrugated cordierite/glass interface.     

国内外堇青石—莫来石窑具材料对比分析

本文对国内外堇青石-莫来石窑具材料进行了显微结构对比，找出存在的差异，分析了对性能的影响。     

Fabrication of Stainless-Steel-Fiber-Reinforced Cordierite-Matrix Composites of Tubular Shape Using Electrophoretic Deposition

Stainless-steel (316L) fiber mats shaped into tubular geometry were used to reinforce cordierite. The cordierite-matrix composites were manufactured using electrophoretic deposition and pressureless sintering. The sintered composites, which had an internal and external deposit thickness of ∼1 mm, were free of surface cracks when a deposition time of 2.5 min was used. Metal-fiber-reinforced cordierite composites such as those developed here may constitute a promising alternative for manufacturing damage-tolerant tubular components for applications at temperatures up to ∼900°C.     

用累托石和滑石粉合成堇青石的研究

堇青石是一种用途广泛的低膨胀材料。利用具有特殊结构的累托石矿物，添加滑石粉成功合成优质堇青石。通过测定样品的吸水率、气孔率、体积密度及热膨胀系数等，并配以XRD，SEM等测试手段，系统研究了其合成工艺。结果表明：利用累托石可以在较低的温度下和较宽的温度范围内合成堇青石。     

堇青石基低膨胀陶瓷材料研究

堇青石是一种优异的抗热震性原料,天然矿物原料很少,一般采用人工合成方法制取。纯堇青石烧成范围非常窄,难以获得致密烧结体。将堇青石原料与磷酸盐,锂铝酸盐复合烧结。可以降低材料的烧结温度,提高其密度,同时仍具有低的膨胀系数。     

Fabrication and Characterization of Cordierite/Zircon Composites by Reaction Sintering: Formation Mechanism of Zircon

The formation mechanism of ZrSiO₄ in the cordierite-ZrO₂ system was studied in the temperature range of 1250° to 1400°C by X-ray diffraction analysis and discussed by analyzing experimental data using some reported reaction models. Nuclei growth models were found to describe the reaction well, and a satisfactory fit was obtained by applying the Avrami equation to estimate the reaction rate constant κ. Different values of the time exponent m were obtained at different temperatures: 0.32 at 1250°C, 0.34 at 1300°C, 0.39 at 1350°C, and 0.49 at 1400°C. The results indicate that there is a progressive change in reaction mechanism.     

堇青石质多孔陶瓷高温过滤材料的研究

主要介绍了堇青石多孔陶瓷高温过滤材料的制备工艺及其性能检测，同时对影响材料性能的各种因素进行了分析和探讨。     

添加剂对合成堇青石的影响

本文研究了锆英砂、碳酸钡、硅线石、氟化钙四种添加剂及其含量对合成堇青石晶相组成的影响。结果表明:四种添加剂的加入均提高了堇青石的含量,且加入量都有一最佳值,分别为锆英砂2wt%、碳酸钡3wt%、硅线石2wt%、氟化钙2wt%。     

累托石和滑石合成堇青石工艺的研究

用X射线衍射、红外光谱和热膨胀仪等先进的测试方法系统地研究了合成温度制度对堇青石样品的结构状态及性能的影响。研究表明：在1200～1350℃的温度范围内,适当提高合成温度,制备的堇青石样品的结晶程度好,Si／Al的有序化程度高,样品的热膨胀系数低,致密化程度高、强度大。