3Y-TZP材料的液相烧结

通过在3Y-TZP(Tetragonal Zirconia Polycrystals stabilized with 3mol% Y2O3)中加入适当含量的硅酸盐玻璃添加剂,使其烧结温度明显降低,并且制备出具有细晶粒、高强度的四方相氧化锆增韧陶瓷材料.本文分析了添加剂对3Y-TZP材料烧结特性及显微结构的影响.发现液相烧结的3Y-TZP具有良好的抗弯强度,但韧性有待于提高.     

烧结助剂添加量对微波烧结3Y-TZP/Al2O3复相陶瓷性能的影响

本文分别以TiO2和MgO纳米粉体为烧结助剂,采用微波烧结技术制备了3Y-TZP/Al2O3复相陶瓷.研究了烧结助剂含量对材料相组成、致密化及力学性能的影响,通过XRD分析了复相陶瓷中t-ZrO2相的相对量变化,并采用SEM观察了弯曲断裂断口形貌.结果表明:随烧结助剂添加量的增加,微波烧结复相陶瓷的致密度、硬度和弯曲强度均有所增加,均优于传统烧结性能,陶瓷颗粒更细.烧结助剂添加量为0.2wt％ MgO、0.4wt％ TiO2,在1300℃微波烧结30 min时试样的致密度为98.1％,显微硬度和抗弯强度分别达18.9 GPa和626 MPa.     

烧结温度对3Y-TZP陶瓷结构与力学性能的影响

以Y2O3为稳定剂,通过无压烧结制备了3mol%钇稳定氧化锆(3Y-TZP)陶瓷,研究了Y2O3不同加入方式、烧结温度对材料相变、显微结构和力学性能的影响.实验结果表明,Y2O3以化学法加入得到的材料中可相变四方相含量高,随温度升高材料致密化程度不断增加,1500℃烧结所得的材料具有最佳的力学性能.     

Al2O3/Y-TZP复相陶瓷的力学性能及耐磨性

通过常压烧结制备了Al2O3/Y-TZP复相陶瓷,研究了Al2O3含量对材料力学性能及耐磨性的影响。体积分数为35%Al2O3的Al2O3/Y-TZP复相陶瓷具有相对高的韧性(12.5MPa·m1/2)和较低的磨损率(9.2×10-6mm3/(m·N))。     

低温烧结3Y-TZP陶瓷的微观结构与力学性能

在 3Y -TZP(tetragonalzirconiapolycrystalsstabilizedwith 3 %Y2 O3inmole)中 ,采用LAS (Li2 O -Al2 O3-SiO2 )玻璃粉料为添加剂 ,在13 0 0～ 15 0 0℃下烧结 ,材料抗弯强度可达 85 0MPa ,断裂韧性可达 8.7MPa·m1 /2 .讨论了添加剂对微观结构及材料力学性能的影响 ,得出了采用LAS作为添加剂 ,不但能显著地降低材料的烧结温度 ,又不会明显削弱材料的力学性能的结论 .     

烧结温度对氧化锆陶瓷相组成及力学性能的影响

本文以经900 ℃、1000 ℃和1100 ℃三种不同温度煅烧处理的3mol%的氧化钇稳定氧化锆粉体为原料,在1450 ℃、1500 ℃和1550 ℃三个温度下烧结致密块体陶瓷.并测定了烧结体的相组成、密度、硬度和断裂韧性等性能.结果表明:经高温煅烧的粉体的烧结致密度随烧结温度的上升而提高;材料的硬度随密度的增加而相应提高;烧结氧化锆的断裂韧性指标主要与材料中亚稳四方相含量有关.     

液相烧结Al2O3/3Y-TZP复相材料的致密化与力学性能

以CaO-MgO-SiO2玻璃为烧结助剂,用液相烧结法制备了氧化铝和3%氧化钇稳定四方氧化锆复相材料.研究了烧结助剂对材料致密化、显微结构及力学性能的影响.结果表明:由于CaO-MgO-SiO2玻璃具有较小的液相粘度,因而对材料的致密化有较大促进作用,可使材料在1 500℃获得致密.烧成温度和材料组成均对Al2O3和ZrO2的平均晶粒尺寸产生影响.显微结构中少量的Al2O3和ZrO2晶粒为晶内分布.引入烧结助剂降低了材料的烧结温度,使材料具有细晶结构,因而具有良好的力学性能,在最佳条件下,样品的抗弯强度可达到778 MPa.     

添加剂对3Y-TZP材料烧结行为及力学性能的影响

在3Y－TZP（tetragonal zirconia polycrystals stabilized,3% Y2O3，摩尔分数）中，采用CAS（CaO-Al2O3-SiO2)玻璃粉料为添加剂，使材料在较低的温度下烧结致密，并具有较好的力学性能，发现液相烧结是使试样的烧结温度显著降低的主要原因。探讨了添加剂对试样的烧结特性及力学性能的影响。与加入LAS添加剂的试样相比，CAS试样的抗弯强度好高，而断裂韧性要差，分析了造成这种力学性能的原因。     

液相烧结8YSZ陶瓷的性能研究

以Bi2O3为烧结助剂,利用液相烧结法制备8YSZ陶瓷材料,研究了烧结助剂对材料致密化、相组成、显微结构、力学性能及电学性能的影响.结果表明:烧结助剂的引入显著促进了材料的致密化、降低了烧结温度;引入烧结助剂Bi2O3后,使得ZrO2中的Y2O3含量减少,以致出现了含有单斜相氧化锆的第二相;而材料的致密化和单斜相氧化锆的出现,又使其具有良好的力学性能,同时对电学性能也有一定的影响.     

纳米3Y-TZP粉体的制备及烧结曲线研究

采用共沉淀法制备纳米3Y-TZP粉体,并利用DSC-TG,XRD和TEM等测试方法对3Y-TZP的物理化学性能进行表征。通过研究纳米3Y-TZP粉体的烧结曲线,分析3Y-TZP素坯在烧结过程的致密化和显微结构。结果表明:在600℃下煅烧2h后,可获得晶粒尺寸为13nm,晶形发育良好、团聚较少的纳米3Y-TZP粉体。在烧结过程中,不同烧结阶段中的扩散机制不同,在烧结后期晶粒尺寸发生显著长大。     

Al2O3添加量对Y—TZP陶瓷烧结及力学性能的影响

研究了Ａｌ２Ｏ３添加量对Ｙ－ＴＺＰ陶瓷烧结及力学性能的影响，结果表明，微量Ａｌ２Ｏ３可固溶于ＺｒＯ２中而提高材料致密度，使Ｙ－ＴＺＰ的强度、耐磨性等力学性能也同时得到提高，过量Ａｌ２Ｏ３处ＺｒＯ２晶界上阻碍致密化，２０ｗｔ％Ａｌ２Ｏ３，１５５０℃，４ｈ未能烧结，使各项力学性能明显下降。     

不同烧结法对3Y-TZP陶瓷力学性能的影响

本文研究了低温烧结含3mol%氧化钇的四方多晶氧化锆(3Y-TZP)的烧结性能和力学性能,以及进行热等静压(HIP)后其力学性能的变化。成形后的3Y-TZP在常压、1300～1450℃温度下进行烧结。由于该粉料有很高的烧结活性,在1300℃低温烧成下就可获得相对密度大于94%的烧结体;在1350℃烧成温度下3Y-TZP获得了最佳的力学性能。其断裂韧性(KIC)和维氏硬度(HV)分别达到18.7MPa.m1/2和13.7GPa,其中应力诱导相变是其主要的增韧机理。对低温烧成的3Y-TZP陶瓷进行热等静压烧结后发现,HIP增大3Y-TZP陶瓷HV的作用显著,可使其增至14.3GPa。     

AlN-Pr2O3液相烧结SiC陶瓷

以AlN、Pr2O3做为SiC陶瓷液相烧结的复合助剂,选定不同的助剂含量(5wt％～ 20wt％)和不同的助剂摩尔比例(Pr2O3/AlN=1/3、1/1、3/1),在1800～2000℃温度下,采用热压和无压烧结的方法制备SiC陶瓷样品,并对这些陶瓷样品的性能进行了研究.实验结果表明,助剂比1/3组的样品显示出更有效地促进SiC陶瓷致密化,该组样品无压烧结最大相对密度为87％,热压烧结具有最高的相对密度96.1％、维氏硬度23.4 GPa、抗弯强度549.7MPa、断裂韧性5.36 MPa·m1/2,显微结构中可观察到晶粒拔出现象,断裂模式为沿晶断裂.     

无压烧结硼化锆基ZrB2-SiC复相陶瓷的结构与性能

以钇铝石榴石-YAG为烧结助剂,通过无压烧结制备了ZrB2-SiC复相陶瓷。研究了烧结助剂含量对烧结材料力学性能和显微结构的影响,材料的显微结构由扫描电镜SEM及其能谱分析EDS测定。研究结果表明,烧结助剂(YAG)和原料中的杂质形成玻璃相填充在晶界上,显著促进了硼化锆基ZrB2-SiC复相陶瓷的致密化。     

Fabrication and characterization of Nb2O5-doped 3Y-TZP materials sintered by microwave technology

The purpose of this research is focused on the manufacture and characterization of a partially stabilized zirconia ceramic with 3 mol% of Yttria and doped with .5 and 1.5 mol% of Nb₂O₅ to analyze the influence of doping, with the purpose of improving the properties before hydrothermal degradation. In the first instance, the microwave sintering process was used for the consolidation of this material, then the physical and mechanical properties were characterized. Together, the results obtained by the conventional sintering process were compared. A low hydrothermal degradation study (LTD) is presented at low temperatures in which possible changes in the mechanical properties of the ceramic materials are analyzed and its influence on the phase transformation that zirconia may present is observed. The mechanical properties were evaluated through hardness, fracture toughness, and Young's modulus tests. Likewise, their density was analyzed, and microstructure was characterized by FESEM. It was found that the microwave-sintered samples at 1200°C exhibited superior properties of toughness than even samples sintered by conventional methods at higher temperatures (1400°C). The sample of 3Y-TZP with 1.5 mol% Nb₂O₅ sintered by microwave with <.2% of porosity achieved a maximum fracture toughness value around 40% higher than the dense monolithic 3Y-TZP material.     

Effect of Sintering Temperature on Phase Transition and Mechanical Properties of Lead Zirconate Ceramics

Phase transition and mechanical properties of PbZrO₃ (PZ) at different sintering temperatures were studied. The Curie temperature depends on the sintering temperature. Hardness and fracture toughness of the PZ were measured using Vickers and Knoop microhardness testers. The lower density at the higher sintering temperature resulting from the loss of lead oxide (PbO) causes the lower value of the Curie temperature, hardness and fracture toughness. The results were well corresponding to the microstructure of the PZ ceramics.     

Liquid Phase Sintered Ceramic Bone Scaffolds by Combined Laser and Furnace

Fabrication of mechanically competent bioactive scaffolds is a great challenge in bone tissue engineering. In this paper, β-tricalcium phosphate (β-TCP) scaffolds were successfully fabricated by selective laser sintering combined with furnace sintering. Bioglass 45S5 was introduced in the process as liquid phase in order to improve the mechanical and biological properties. The results showed that sintering of β-TCP with the bioglass revealed some features of liquid phase sintering. The optimum amount of 45S5 was 5 wt %. At this point, the scaffolds were densified without defects. The fracture toughness, compressive strength and stiffness were 1.67 MPam^1/2, 21.32 MPa and 264.32 MPa, respectively. Bone like apatite layer was formed and the stimulation for apatite formation was increased with increase in 45S5 content after soaking in simulated body fluid, which indicated that 45S5 could improve the bioactivity. Furthermore, MG-63 cells adhered and spread well, and proliferated with increase in the culture time.