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从羟基磷灰石的研究现状和多孔生物陶瓷材料的特性入手,分析出羟基磷灰石多孔陶瓷是目前最有应用前景的种植材料,但是在改善羟基磷灰石陶瓷的力学性能方面的研究中,存在增强材料与基体热膨胀系数不匹配、复合材料成孔机理和强度关系不明确以及生物活性受到影响等问题.提出了用天然针状硅灰石增韧多孔羟基磷灰石材料的制备方法. 相似文献
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以羟基磷灰石(Hydroxyapatite, HAp)为基体, 石墨烯(Graphene, rGO)作为增强相, 利用等离子活化烧结制备了石墨烯/羟基磷灰石(rGO/HAp)复相生物陶瓷。系统研究了rGO添加量对HAp陶瓷基体物相结构、生物活性及断裂韧性的影响。结果表明, rGO的加入有利于提高HAp陶瓷的生物活性。同时, 复相生物陶瓷的硬度与断裂韧性随rGO添加量的增加均表现出先升高, 后显著降低的变化趋势。当rGO添加量为2wt%时, 样品的硬度与断裂韧性分别达到6.97 GPa和0.84 MPa•m1/2, 较纯相HAp陶瓷提高了11.5%和37.3%。研究表明rGO的拔出效应是导致复相陶瓷力学性能提高的主要原因。 相似文献
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冲击波改性的羟基磷灰石陶瓷及其体外溶解性能 总被引:3,自引:0,他引:3
析了经冲击波处理的羟基磷灰石粉末的活性,比较了由经过冲击波处理的羟基磷灰石粉末及未经冲击波处理的羟基磷灰石粉末烧结得到的两种陶瓷在模拟体液中的溶解性能。研究结果表明:利用冲击波技术处理羟基磷灰石,能达到使羟基磷灰石粉末细化与均化的目的,并在粉末内产生晶格畸变,提高烧结活性及强度,由这种粉末制得的陶瓷在模拟体液中溶解较弱,性能更加稳定。 相似文献
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生物羟基磷灰石的合成 总被引:1,自引:0,他引:1
综述了生物羟基磷灰石合成研究的最新进展,重点介绍和评述了羟基磷灰石的合成与制备方法,讨论了各种方法的特点和应用前景。最新的研究动态表明,羟基磷灰石研究从基本的化学反应合成向生物矿化与新生骨引导机理及硬组织再造技术方向发展。同时,羟基磷灰石在金属、陶瓷等植入体表面的涂层、以及天然材料制备羟基磷灰石依然是其合成研究的主要方向。 相似文献
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Hsu YH Turner IG Miles AW 《Journal of materials science. Materials in medicine》2007,18(12):2319-2329
Porous hydroxyapatite/tricalcium phosphate (HA/TCP) bioceramics were fabricated by a novel technique of vacuum impregnation
of reticulated polymeric foams with ceramic slip. The samples had approximately 5–10% interconnected porosity and controlled
pore sizes appropriate to allow bone ingrowth, combined with good mechanical properties. A range of polyurethane foams with
20, 30 and 45 pores per inch (ppi) were used as templates to produce samples for testing. The foams were inpregnated with
solid loadings in the range of 60–140 wt%. The results indicated that the average apparent density of the HA/TCP samples was
2.48 g/cm3, the four-point bending strength averaged 16.98 MPa, the work of fracture averaged 15.46 J/m2 and the average compressive strength was 105.56 MPa. A range of mechanical properties resulted from the various combinations
of different grades of PU foam and the solid loading of slips. The results indicated that it is possible to manufacture open
pore HA/TCP bioceramics, with compressive strengths comparable to human bone, which could be of significant clinical interest. 相似文献
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G. Willmann 《Materialwissenschaft und Werkstofftechnik》2003,34(2):198-202
Sterilization can change properties of bioceramics Bioceramics made of bioinert alumina or zirconia and bioactive hydroxyapatite are well established implant materials. Implants have to be cleaned and sterilized. When sterilized some bioceramics change their color. This may effect their properties. No decrease of mechanical strength is observed when sterilizing alumina and the novel ceramic biocomposite AMC (Alumina Matrix Composite) with steam or Co60 Gamma irradiation. When sterilizing Y‐TZP zirconia with steam a decrease of strength is observed. 相似文献
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Hsu YH Turner IG Miles AW 《Journal of materials science. Materials in medicine》2007,18(12):2251-2256
The aim of this study was to fabricate porous implant materials with graded pore structures similar to the bimodal structure
of cortical and cancellous bone. Porous hydroxyapatite/tricalcium phosphate (HA/TCP) bioceramics with interconnected porosity
and controlled pore sizes required to simulate natural bone tissue morphology were fabricated by a novel technique of vacuum
impregnation of reticulated polymeric foams with ceramic slip. Functionally gradient materials (FGMs) with porosity gradients
were made by joining different pore per inch (ppi) foams together by either stitching or pressfitting to form templates. Post
production, no defects could be seen at the interface between the two different porosity sections. The macropore sizes of
the HA/TCP bioceramics were larger than 100 μm which is appropriate for bone ingrowth. A sample with a graded porous structure
which is close to the human bone morphology was also developed. The two component structures were conspicuously different
but joined together firmly. Four point bend testing of FGM samples showed them to have similar mechanical properties to homogeneous
ceramics based on foam templates with uniform pore sizes, with no evidence of interfacial weakness. Many potential biomedical
applications could be developed utilising graded porous structures. The ease of processing will make it possible to fabricate
a range of complex shapes for different applications. 相似文献
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《Materials Letters》2007,61(11-12):2270-2273
We fabricated highly porous hydroxyapatite (HA) bioceramics using the camphene-based freeze casting method. In this method, HA/camphene slurries with various HA contents (10, 15, and 20 vol.%) were prepared by ball-milling at 60 °C and then cast into a mold at room-temperature. This method allowed the fabricated sample to have completely interconnected pore channels by removing the frozen camphene network via sublimation and dense HA walls by sintering the highly packed HA powder networks at 1250 °C for 3 h. As the initial HA content was increased from 10 to 20 vol.%, the porosity decreased from 75 to 56%, while the compressive strength remarkably increased from 0.94 to 17 MPa. 相似文献
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生物陶瓷表面纳米结构能够影响成骨细胞增殖和分化, 其表面微观结构的控制, 特别是烧结前晶粒取向调控, 是设计开发生物活性陶瓷的关键之一。针对羟基磷灰石晶粒取向调控问题, 重点研究了铁掺杂羟基磷灰石晶体在强磁场中的取向。分别采用共沉淀法和共沉淀-水热法合成了羟基磷灰石(HA)和铁-羟基磷灰石(Fe-HA), 通过XRD、SEM、TEM、PPMS和ICP等对HA和Fe-HA的物相、微观形貌、磁学性能、元素组成进行了表征和分析。研究发现:Fe-HA物相与HA相同, 没有明显的杂质相; HA为抗磁性, Fe-HA转化为顺磁性; 共沉淀法粉体为针状, 共沉淀-水热法粉体为短棒状, 针状粉体在强磁场中不能定向, 短棒状粉体能够定向; 在单一方向强磁场中, HA不能单轴定向, Fe-HA能够在一定程度上沿c轴取向。 相似文献
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Two-step sintering of dense, nanostructural forsterite 总被引:1,自引:0,他引:1
This paper investigates a method for preparing the nanocrystalline forsterite dense ceramic via sintering the forsterite nanopowder. The two-step sintering (TSS) method has been applied to suppress the accelerated grain growth of forsterite nanopowder compacts. The effects of sintering parameters on the mechanical properties and the microstructure characteristics of the forsterite ceramic were studied. Results verified the applicability of this method to suppress the final stage of grain growth in the system. The grain size of the high density compacts (~ 98.5% TD) of the forsterite was 60-75 nm. The optimal hardness (940 Hv) and fracture toughness (3.61 MPa.m1/2) of the prepared nanocrystalline forsterite were found to be higher than those of the currently available hydroxyapatite bioceramics. It was concluded that the two-step sintering method can be used to fabricate improved forsterite dense ceramics with desired bioactivity and mechanical properties that might be suitable for hard tissue repair and biomedical applications. 相似文献
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针对常规马弗炉烧结钙磷生物陶瓷温度高、烧结时间长,制品晶粒粗、强度和生物学活性难于同时提高的问题,采用微波等离子体新技术烧结了多孔HA/β-TCP双相生物陶瓷。实验结果显示,和常规马弗炉烧结法相比,微波等离子体烧结可在极短的加热时间内,制得线收缩率较大,晶粒尺寸小,抗压强度更大的多孔HA/β-TCP双相生物陶瓷。通过模拟体液的浸泡实验发现,其类骨磷灰石形成量也明显多于常规马弗炉烧结。这预示微波等离子体烧结是一种既能提高钙磷材料的力学强度,同时又可能增加其生物学活性的新烧结方法。 相似文献
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Yan Zhang Kechao Zhou Yinxiang Bao Dou Zhang 《Materials science & engineering. C, Materials for biological applications》2013,33(1):340-346
Freeze casting of aqueous suspension was investigated as a method for fabricating hydroxyapatite (HA) porous ceramics with lamellar structures. The rheological properties of HA suspensions employed in the ice-templated process were investigated systematically. Well aligned lamellar pores and dense ceramic walls were obtained successfully in HA porous ceramics with the porosity of 68–81% and compressive strength of 0.9–2.4 MPa. The results exhibited a strong correlation between the rheological properties of the employed suspensions and the morphology and mechanical properties of ice-templated porous HA ceramics, in terms of lamellar pore characteristics, porosities and compressive strengths. The ability to produce aligned pores and achieve the manipulation of porous HA microstructures by controlling the rheological parameters were demonstrated, revealing the potential of the ice-templated method for the fabrication of HA scaffolds in biomedical applications. 相似文献
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This paper reports the effects of processing densification on the mechanical properties of hydroxyapatite bioceramics. Densification of synthetic hydroxyapatite is conducted in the range 1000-1300 °C. X-ray diffraction and SEM microscopy are used to check the microstructure transformations. Vickers hardness, toughness and Young's modulus are analyzed versus the density and grain size. The sintering temperature and the particle size influence strongly the densification and the resulting mechanical properties. In addition, the critical sintering temperature appears around 1200 °C and the declined strength at the temperature up to 1200 °C is found sensitive to the dehydroxylation process of hydroxyapatite. 相似文献