FHA bioceramic composite materials enhanced by ZrO2

Experiments for investigating the problem to improve the mechanical properties of FHA [Ca₁₀(PO₄)₆F(OH)] biomaterial have been presented in this paper. ZrO₂ micro-particle, as strengthening phase, is added into FHA matrix material to make a composite biomaterial. Various mechanical properties were tested. Distribution behaviour of ZrO₂ particle in sintered material and phase structure changes of material at elevated temperature were investigated by means of X-ray and SEM. Some biologic experiments were also carried out on animals to estimate the biological function of the composite material. Project supported by the National Natural Science Foundation of China Synopsis of the first author Ruan Jianmin, associate professor, born in 1957, specializing in powder metallurgy as well as bioceramic materials     

相变对ZrO2／SiO2多层膜激光损伤阈值的影响

摘要：用电子束蒸发法制备出ZrO2／SiO2和YSZ／SiO2多层膜,分别测定了薄膜结构特性和激光损伤阈值. 实验结果表明：Y2O3稳定的ZrO2镀膜材料在电子束蒸发过程中不会发生相变,而未稳定的ZrO2则必然发生相变产生喷溅,使缺陷增加,从而使损伤阈值降低. 通过分析认为相变引起的缺陷是YSZ／SiO2和ZrO2／SiO2高反膜损伤阈值差别的主要原因.     

Mechanical Properties of ZrO_2 Ceramic Stabilized by Y_2O_3 and CeO_2

ZrO2 ceramic was made from evenly dispersed ( Y, Ce)-ZrO2 powder with different compositions , which was prepared by the chemical coprecipitation, and stabilized by compound additions through appropriate techniques. And its mechanical property that is related to the phase content and its microstructwe was studied by X-ray diffraction(XRD) , scan electron microscope( SEM). The results show that Y2O3 has stronger inhibition to the growth of ZrO2 crystal than CeO2 has. Therefore, within an appropriate composition range of Y2 O3 and CeO2, the higher the content of Y2O3, the lower the content of CeO2 , the smaller ZrO2 crystal. Combining this feature and the stabilization technique with complex additions instead of simple addition, ZrO2 ceramic with high density and excellent mechanical properties can be made under normal conditions. It is concluded that the improvement of mechanical properties originates from the toughening of microcrack, phase transformation and the effect of grain e-vulsions.     

ZrO2/316L不锈钢复合材料的SEM分析

采用热压（ＨＰ）烧结法制备了ＺｒＯ２／３１６Ｌ不锈钢复合材料．利用三点弯曲、单边切口梁(ＳＥＮＢ）等方法测定了材料的力学性能．通过扫描电镜(ＳＥＭ）现察复合材料的显微组织结构，研究 分析了材料在静载荷下的断裂机理．     

ZrO2含量对WC基复合材料的力学性能和微观结构的影响

摘要：以提高WC基复合陶瓷的断裂韧性和硬度为目标,利用ZrO2作为材料粘结剂和增强相,同时引入Al2O3添加相,采用热压烧结工艺成功制备了WC-ZrO2-Al2O3(WZA)复合刀具材料.在此基础上,添加一定量的VC作为晶粒生长抑制剂和助烧剂,以实现材料最大程度的致密化.并对热压后复合材料的硬度、抗弯强度和断裂韧性进行了测试和分析.探讨了ZrO2含量对材料微观结构和力学性能的影响,研究了复合材料断面断裂方式和材料相的组成.     

杂凝聚法制备纳米复相陶瓷材料的微观组织及增韧机理研究

采用杂凝聚法制备了Al2O3-ZrO2(n)纳米复相陶瓷粉体,对经SPS烧结成型的纳米复相陶瓷材料块体进行了微观组织韧化机理的试验研究.研究表明,Al2O3-ZrO2(n)陶瓷中由于ZrO2的添加,改变了Al2O3的晶粒形状,提高了材料的致密度,并细化了晶粒;其微观组织为典型的晶内/晶界混合型纳米复相陶瓷,其中不规则的ZrO2团聚体主要存在于Al2O3的多晶粒相交的晶界处,一些细小、分散的球状ZrO2纳米颗粒(70~200 nm)分布在Al2O3晶粒内部.由于基体晶粒的细化以及因其形成的"内晶型"纳米结构,提高了基体的力学性能.研究认为,Al2O3-ZrO2(n)纳米复相陶瓷力学性能的改变是由于纳米粒子的增韧机制、ZrO2相变增韧机制和"内晶型"结构共同作用的结果.     

电熔MgO-ZrO2原料显微结构的研究

以轻烧氧化镁和锆英石为原料,采用电熔法制备了MgO-ZrO2合成料,利用扫描电子显微镜和能谱仪对材料的显微结构进行了分析,计算了材料中各物相的化学组成,探讨了其显微结构的形成过程.研究结果表明,在电熔过程中锆英石分解产生的S iO2在晶界的低钙区域中以2MgO.S iO2的形式存在,而在高钙区域将生成MgO.S iO2.CaO玻璃相.基体中的MgO和杂质中的CaO将进入ZrO2晶格中形成（MgO＋CaO）ZrO2固溶体,该固溶体在降温过程中会析出MgO,并在其晶粒周围形成富镁的2MgO.S iO2相.     

Effect of nucleating agents on microstructure and mechanical properties of SiO2-Al2O3-ZrO2 glass-ceramics

SiO2-Al2O3-ZrO2 glasses with different nucleating agents were crystallized under special processing schedule. The microstructure and mechanical properties of the glass-ceramics in SiO2-Al2O3-ZrO2 system were investigated by differential scanning calorimetry, scanning electron microscopy, X-ray diffraction and three-point bending method. The results show that ZrO2 is not an effective nucleating agent in SiO2-Al2O3-ZrO2 system, while TiO2 is effective for the separation of spinel, and P2O5 facilitates solubility of ZrO2 in glass and crystallization. The main crystalline phases of the glass-ceramics are spinel, anorthite and tetragonal zirconia. With the increase of ZrO2 content in the glass, glass-ceramics show higher bending strength （120 MPa） than others.     

沉淀法制备ZrO2中制备方法对氧化锆晶相的影响

以氧氯化锆为前驱物,用沉淀法制得了纳米氧化锆（ZrO2）粒子,并探讨了沉淀过程中沉淀剂加入速度、洗涤和干燥方式对ZrO2晶粒尺寸和晶型转变的影响。结果表明,合成过程中干燥方式对ZrO2样品的尺寸影响最大。沉淀剂的加入速度越快,越有利于四方晶相ZrO2的稳定,在制备过程中采用醇洗、真空干燥的方式比水洗、空气干燥更有利于抑制ZrO2从四方相到单斜相的相变。     

纳米材料ZrO2微波增强光催化降解染料

采用溶胶—凝胶再结合程序升温溶剂热法低温制备了晶型结构良好、孔径分布较均匀且比表面积为130．4m^2／g的纳米光催化材料ZrO2。在微波无极灯照射下,以光催化降解染料为反应体系．研究了该纳米材料微波增强光催化性能。实验结果表明．在微波作用下．ZrO2的光催化活性显著增强。     

MgO和ZrO2包覆对正极材料结构和电性能的影响

通过共沉淀法制备了前驱体Ni1/3Co1/3-xMn1/3（OH）2,然后与LiOH·H2O、不同金属氧化物（MgO、ZrO2）分别混合制备锂离子电池正极材料LiNi1/3Co1/3-xMn1/3MxO2（M=Mg,Zr）.通过X射线衍射（XRD）、扫描电镜（SEM）、高精度电池测试系统、交流阻抗对材料结构和电化学性能进行了表征。实验结果表明,包覆MgO后,材料的结构发生变化,而包覆ZrO2没有改变正极材料的结构。与无包覆的正极材料相比较,包覆ZrO2材料的首次放电量为119.07 mAhg-1,20次循环后容量保持率为92.64%,放电量仍达到110.31 mAhg-1。     

热处理对热障涂层材料Y_2O_3部分稳定ZrO_2性能的影响

热障涂层用于燃气轮机的热端部件,可以显著提高其使用温度,延长热端部件的使用寿命,并增大燃气轮机发动机的效率.利用Y2O3和ZrO2为原料,通过固相合成法合成了Y2O3(w(Y2O3)=6%~8%)部分稳定的ZrO2(Y-PSZ)热障涂层陶瓷顶层,并对此陶瓷顶层的微观形貌、相组成进行了研究.同时研究了热处理对热障涂层材料Y-PSZ性能的影响.     

（Y—ZrO_2）－Al_2O_3陶瓷（AZ）的摩擦磨损

通过ＳＥＭ、ＴＥＭ和ＸＲＤ等手段对以Ｙ２Ｏ３为稳定剂ＺｒＯ２增韧的Ａｌ２Ｏ３陶瓷复合材料的显微结构、力学性能及与钢对摩时的摩擦磨损行为进行了系统分析，并对其微观机理做了初步探讨．结果表明，转移层的出现对对摩材料起到了保护作用；ＺｒＯ２的加入提高了材料的耐磨性能，但摩擦高温会导致ＺｒＯ２ｔ→ｍ相交增韧作用失效．     

水热法合成条件对氧化锆晶相影响的光谱研究

以硝酸锆为前驱物,用水热法分别合成了纯单斜相、四方相以及四方和单斜混合相的氧化锆纳米粒子.应用XRD、拉曼光谱和TEM探讨了水热过程中前驱体浓度、晶化温度和晶化时间对ZrO2晶粒尺寸和相变的影响.结果表明,水热制备过程中上述合成条件均影响ZrO2晶粒尺寸,其中晶化温度对其影响最大,但是晶化温度对ZrO2的形貌影响不大.延长晶化时间有利于单斜晶相的形成,而且随着晶化时间延长,ZrO2的晶化程度增加.在水热合成过程中采用较低的前驱体浓度、较高晶化温度及延长晶化时间有利于控制合成单斜相ZrO2.     

ZrO_2／SO_4~(2－)固体超强酸催化剂研究（Ⅱ）——表面化学和酸中心形成过程

用ＸＲＤ、ＬＲＳ研究了ＺｒＯ２／ＳＯ２－４和ＺｒＯ２晶相。用Ｎ２吸附法、化学分析法和滴定法测定了ＺｒＯ２／ＳＯ２－４的比表面、Ｓ含量和酸强度，ＸＰＳ测定ＺｒＯ２／ＳＯ２－４的能量。实验结果表明，ＳＯ２－４的存在延迟了ＺｒＯ２的晶变，提高了晶变温度，在ＺｒＯ２／ＳＯ２－４体系中不存在水和游离Ｈ２ＳＯ４，体系酸强度最高时ＺｒＯ２主要呈四方晶系。     

ON ZrO_2-NiCr COMPOSITE POWDER FOR SPRAYING

Composite powder prepared of calcium ox-ide stabilzed ZrO_2 (CSZ)and NiCr by vacuum sintering isstudied, and the effect of additive TiO_2,on its properties isdiscussed. The morphology and phases of the powder weremeasured and determined by SEM.EPMA. XRD methodsand the testing of flowability, bulk density and microhard-ness. The results show that the metallic camponents in thepowder are in homogeneous distribution,the flowability.bulkdensity and microhardness are superior to the ZrO_2-NiCrpowder prepared by mechanically mixing. All components inthe coating made of the composite powder are well-distribut-ed because of avoiding segregation in the middle of mixing.It proves that the comopsite powder is an excellent materialfor plasma spraying.     

ZrO_2:Eu~(3+)纳米晶发光和能量传递性质研究

利用共沉淀方法制备了ZrO2:Eu3+荧光粉体,研究了不同煅烧温度和掺杂浓度对样品结构和发光性质的影响. 在不同煅烧温度和掺杂浓度下,样品结构含有单斜相和四方相2种不同结构,其比例不同. 在不同温度下,监测615 nm的激发光谱发现:基质ZrO2和Eu3+之间存在能量传递,当样品结构为单斜相时,能量传递最强;研究激发波长为243 nm的发射光谱可知:晶面结构不同可以引起Eu3+特征发射光谱的变化. 研究荧光强度与激活离子Eu3+浓度关系发现:荧光强度先随浓度提高而提高,在浓度为4 mol%时达到最大,然后又随之降低.     

Degration of Partially Stabilized Zirconia Ceramics under an Applied Stress

Partially stabilized zirconia ceramics were sintered using fine powder of ZrO2-3mol % Y2O3 prepared by the chemical co-precipitation method. The tetragonal-to-monoclinic phase transformation in ZrO2 ceramics during the aging in boding water and the effect of an applied stress of 100MPa were mainly investigated.The degradation of ZrO2 ceramics is considered to be caused by the reaction between Y2 O3 and H2O, which leads to a decreasing in the stability of tetragonal phase of ZrO2. It is found that the tensile stress improves the driving force of the phase transformation and acoelerates the degradation while the compressive stress has no obvious effect on the deeradation.     

BaZrO3颗粒分散混合导体YBa2Cu3O7-δ的微结构与性能研究

通过在YBa2Cu3O7-δ的起始原料中直接掺入过量的BaO和等摩尔ZrO2,原位生成均匀弥散分布的BaZrO3第二相颗粒的方法制备YBa2Cu3O7-δ-BaZrO3复合混合导体材料.研究了引入第二相BaZrO3颗粒对基相YBa2Cu3O7-δ的微观结构、热膨胀行为和力学性能的影响.发现弥散的BaZrO3颗粒能有效地抑制YBa2Cu3O7-δ沿C轴方向的生长,使晶粒由条形变为方形.与YBa2Cu3O7-δ单相样品相比,含10 mol%BaZrO3颗粒的样品具有更高的相对密度和较低的热膨胀系数以及显著改善的力学强度.     

粒径对氧化锆纳米粒子结构的影响

对粒径在58～10nm范围内不同粒度的纯ZrO2粒子进行了喇曼散射光谱研究。结果表明,粒子的点阵结构受表面效应的影响,表面效应将进一步引起ZrO2粒子点阵结构变化。在室温下,ZrO2粒子由单斜相向四方相转变的临界直径为15nm。