工艺因素对C_((f))/HA-PMMA生物复合材料弯曲性能的影响

采用原位合成与溶液共混相结合的方法,制备了短切碳纤维(C_((f)))增强纳米羟基磷灰石(HA)-聚甲基丙烯酸甲酯(PMMA)生物复合材料.分别研究了丙烯腈基短切碳纤维含量、引发剂(过氧化苯甲酰,BPO)用量和HA的质量分数对复合材料弯曲强度和弯曲模量的影响.采用万能材料试验机和扫描电子显微镜对复合材料的弯曲性能及断面的微观形貌进行了测试和表征.结果表明,在一定质量分数范围内,分别增加碳纤维含量、BPO用量或HA的含量,复合材料的弯曲强度和模量均呈现先增大后减小的趋势.当C_((f))含量为4%、BPO用量为1.6%和HA质量分数为8%时,复合材料的抗弯曲强度和模量达到最大值,分别为130 MPa和4.47 GPa.     

G(f)/HA-CS复合材料的制备及性能研究

以羟基磷灰石-壳聚糖(HA-CS)为基体,玻璃纤维G(f)为增强相,采用原位杂化法制备短玻璃纤维增强HA-CS基生物复合材料.研究交联剂、羟基磷灰石含量和玻璃纤维含量对复合材料性能的影响.采用红外吸收光谱、扫描电子显微镜和万能材料试验机对材料的结构和性能进行表征.结果表明:原位杂化法能制备性能较好的复合材料;用戊二醛交联改性复合材料可以明显增加其韧性和弯曲强度,使复合材料抗弯曲强度提高16%;当CS/HA=10/1(质量比)和玻璃纤维含量为1.5%时复合材料抗折强度达到极大值84.47 MPa;随玻璃纤维含量的增加,复合材料的断裂面由平整向多层断裂变化,材料的韧性有所提高.     

微束等离子喷涂氧化锆增韧羟基磷灰石复合涂层

采用微束等离子喷涂方法,在Ti-6Al-4V基体上制备了羟基磷灰石 氧化锆(70HA-30ZrO2,质量分数,%)复合涂层.将复合涂层置于模拟体液中分别浸泡了3,7,14,28 d并观察表面磷灰石的生长情况以评价涂层生物活性.采用扫描电镜(SEM)和X射线衍射(XRD)分析技术对涂层浸泡前后的表面形貌和相组成进行了研究.结果表明,涂层中ZrO2主要以立方相存在;喷涂过程中羟基磷灰石(HA)出现了一定的分解,产生大量的α-Ca3(PO4)2杂质相.HA涂层熔化效果很好,但涂层中有未熔化的ZrO2颗粒.涂层在模拟体液中浸泡28 d后表面可以形成磷灰石,说明涂层具有很好的生物活性.     

医用镁合金ZrO2陶瓷膜制备及其骨生物活性研究

为了提高医用镁合金的耐蚀性及骨生物活性,分别在锆盐体系和硅酸盐体系溶液中,采用微弧氧化技术在镁合金表面制备具有生物活性的陶瓷膜。利用X射线衍射仪分析了陶瓷膜的相成分,并通过Hank’s体液模拟试验研究了陶瓷膜表面形貌演变和Ca、P等元素的含量变化。研究结果表明:锆盐体系溶液中制备的陶瓷膜主要由ZrO2和MgF2组成;硅酸盐体系溶液中制备的陶瓷膜主要由MgSiO3和MgO组成。在模拟体液浸泡过程中,陶瓷膜未发生腐蚀,表明对镁合金基体具有良好的防护作用。在体液浸泡7 d至14 d,陶瓷膜表面有团状物形成;浸泡21 d后,表面出现蠕虫状的羟基磷灰石形貌;同时,陶瓷膜表面的Ca、P元素含量随浸泡时间延长逐渐增加;其中,锆盐体系溶液中制备陶瓷膜表面的Ca/P比达到1.445,接近羟基磷灰石中的Ca/P比(1.67)。     

先驱体裂解HA/CaSiO3多孔材料及性能

采用先驱体裂解法以聚碳硅烷(PCS)和碳酸钙(CaCO3)作为硅灰石(CaSiO3)的前驱体于1200℃常压烧结制备了羟基磷灰石/硅灰石多孔支架材料.采用 XRD 对材料进行物相分析;SEM进行材料内部组织结构的观察;万能试验机测其压缩强度;阿基米得法测其气孔率;模拟体液试验评估其生物活性.结果表明:制备的材料主晶相为羟基磷灰石和硅灰石,气孔率介于70%～80%之间,当硅灰石质量分数为30%时,支架的压缩强度达到3,48 MPa,气孔率为78.2%,且材料具有良好的生物活性.研究表明了先驱体裂解法制备HA/CaSiO3细胞支架的可行性.     

预钙化处理提高钽的表面生物活性

为提高钽的生物活性,对钽进行了NaOH溶液碱处理,利用模拟体液(SBF)浸泡实验探索碱处理的最佳浓度。碱处理后的钽又分别在CaCl2溶液和K2HPO4溶液中进行预钙化处理。钽经过0.7mol/L的碱处理后,在SBF中浸泡2周,表面即可被羟基磷灰石覆盖。经预钙化处理后,钽在SBF中浸泡4天,表面即可覆盖一层羟基磷灰石,说明预钙化大幅提高了钽的生物活性。其机理是预钙化处理可使样品表面迅速完成钙磷化合物的形核,浸入SBF以后羟基磷灰石可以迅速长大。     

超音速氧焰喷涂HA/BG涂层的制备及表征

利用超音速氧焰喷涂(HVOF)在Ti6A14V基体上制备了羟基磷灰石(HA)/生物玻璃(BG)涂层,考察了涂层的相组成、表面形貌及生物活性.XRD显示:涂层的结晶相为HA,未检测到HA分解产物,添加生物玻璃不影响涂层的相组成;SEM结果表明:HA颗粒熔化较少,计算熔化比例为13%,BG颗粒以球形方式镶嵌在涂层表面,含量小于粉末中的比例:涂层浸泡在模拟体液中7天后发现:添加20%BG的涂层表面有类骨类磷灰石涂层生成,说明添加BG可以提高涂层的生物活性.     

放电等离子烧结技术制备(Ti-35Nb-7Zr-5Ta)-15HA复合材料微观组织的演变及生物活性

为了提高生物材料的生物活性并降低弹性模量,利用放电等离子烧结技术制备(Ti-35Nb-7Zr-5Ta)-15HA生物复合材料,研究不同烧结温度(950~1150℃)对复合材料相对密度、微观组织演变、力学性能及生物活性的影响。结果表明:随着温度的升高,复合材料相对密度从87.6%提高到97.5%;复合材料主要由β-Ti相、α-Ti相及陶瓷相,如Ti2O、CaZrO3、CaO、Ti5P3和Ca3(PO4)2等组成;复合材料的弹性模量为30~95 GPa、抗压强度为593~1978 MPa,而且随着烧结温度升高呈增大趋势;同时,在模拟体液中浸泡14 d后,复合材料表面能够获得类骨磷灰石,显示出良好的生物活性,但随着温度的升高,类骨磷灰石含量不断减少。因此,950℃下烧结的(Ti-35Nb-7Zr-5Ta)-15HA生物复合材料是潜在的良好的生物植入材料。     

CaO-P2O5-Na2O-B2O3溶胶-凝胶玻璃陶瓷体外磷灰石的形成和生物活性

采用溶胶-凝胶法制备CaO-P2O5-Na2O-B2O3玻璃陶瓷前驱体粉末,经过烧结热处理获得以β-Ca2P2O7为主晶相,CaPO3(OH)为次晶相的玻璃陶瓷。将试样在模拟体液中浸泡不同时间,采用XRD,SEM和EDX分析B2O3对试样表面磷灰石形成的影响。将MC3T3-E1细胞与玻璃陶瓷复合培养,通过SEM观察细胞的粘附和增殖行为。结果表明:B2O3的加入可以有效抑制析晶,稳定玻璃结构;试样在模拟体液中浸泡7d后,玻璃陶瓷表面有大量羟基磷灰石形成;细胞在支架材料上培养3~7d,呈现出良好的粘附和生长;表明B2O3的加入可以促进磷灰石矿化层的形成,提高材料的生物活性。     

生物可降解羟基磷灰石颗粒增强镁基复合材料的制备及表征(英文)

采用粉末冶金方法制备了生物可降解的纯镁基体和不同百分含量的羟基磷灰石颗粒增强镁基复合材料。通过压缩试验和电化学测试对复合材料的机械性能和耐腐蚀性能进行了研究。结果表明,复合材料的压缩屈服强度明显高于纯镁基体,并且随着羟基磷灰石含量的增加而提高;电化学测试结果表明,复合材料在生物模拟体液中的腐蚀电位与纯镁基体相比明显提高,其中Mg-20%HA复合材料的腐蚀电位为-1.582 V,腐蚀电流密度为10.84μA/cm2。     

FeCrAl纤维对FeCrAl(f)/HA复合材料显微结构及力学性能的影响(英文)

采用热压工艺制备FeCrAl纤维增强的FeCrAl(f)/HA生物复合材料,通过金相显微镜、X射线衍射、扫描电子显微镜(SEM)以及能谱(EDS)等测试手段对试样的微观结构及成分进行观察和表征。采用三点抗弯法测定FeCrAl(f)/HA复合材料试样的力学性能。研究结果表明:复合材料的性能随FeCrAl纤维加入得到提高,并随着纤维含量(0～11%,体积分数)的增加逐渐明显下降。HA基体和FeCrAl纤维界面结合紧密,互相咬合较深,并在两相上出现了一定程度的互扩散。FeCrAl(f)/HA生物复合材料的最优化参数如下:纤维直径22μm,长度1-2mm、体积分数7%左右。     

炭/炭复合材料声电沉积钙磷生物活性涂层的生长机理

通过声电沉积在炭/炭复合材料表面制备钙磷生物活性涂层,采用SEM（带EDAX）,XDR,FTIR研究电沉积时间对钙磷生物活性涂层的形貌、结构和组成的影响.实验结果表明：沉积初始先在炭/炭表面形成无定形层,片状磷酸氢钙（DCPD）在其表面生长,随着电沉积时间的延长,逐渐向针状的羟基磷灰石Ca10（PO4）6（OH）2（HA）转变,涂层厚度和n（Ca）/n（P）不断增加,涂层的结晶度和电解液的pH值下降.涂层为缺钙磷灰石.同时探讨了在炭/炭复合材料表面钙磷生物活性涂层的生长机理.     

The effect of plasma spraying power on the structure and mechanical properties of hydroxyapatite deposited onto carbon/carbon composites

This paper deals with the effect of plasma spraying power on hydroxyapatite (HA) coatings on carbon/carbon composites (C/C composites). The microstructure and phase composition of the as-sprayed coatings have been examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The shear strength of the HA coatings–C/C substrates was detected on a RGD-5 tensile testing machine. Results indicate that the melting extent and the shear strength of the coatings were evidently improved with the increasing of spraying power. Moreover, the amount of decomposed phases is increased and the content of crystalline HA of coatings was slightly changed. Observation of fracture surfaces shows that carbon fiber bundles can bond well with HA coatings using 40 kW spraying power.     

2.5D SiO_(2f)/SiO_2复合材料制备工艺及性能研究

采用溶胶-凝胶工艺制备2.5D SiO_(2f)/ SiO_2复合材料,并对工艺参数进行了优化.研究表明:以固含量为30.73 %的硅溶胶为浸渍浆料,采用微波干燥方式,烧结温度为900 ℃时制备的复合材料具有较好的性能.经过7个制备周期后,复合材料的密度为1.65 g/cm~3,此时弯曲强度最大,可达80.7 MPa;800 ℃下烧成的材料具有最大的剪切强度和断裂韧性,分别为56.6 MPa和3.5 MPa·m~(1/2).测得试样介电常数为3.4,较好的满足了天线罩材料的介电性能要求.     

Influence of hydrothermal temperature on hydroxyapatite coating transformed from monetite on HT-C/C composites by induction heating method

Hydrothermal post-treatment was used to convert monetite coating fabricated by induction heating method on H₂O₂ treated C/C (HT-C/C) composites to an adherent HA coating. The monetite coatings were hydrothermally treated for 4 h at 373 K, 403 K, 423 K, and 453 K in a 50 mL autoclave. After hydrothermal post-treatment, the structure, morphology and the chemical composition of these HA coatings were characterized with XRD, FTIR SEM and EDS. A scratch test was conducted to measure the strength of the adhesion of the coatings to the HT-C/C substrate. The results showed that the degree of crystallinity and the Ca/P ratio of the HA coatings increased with increasing hydrothermal temperature. The submicron-level morphology and adhesion of the HA coatings were highly affected by the hydrothermal temperature. From the results, it can be suggested that 423 K was the best hydrothermal treatment temperature for the HA coatings which were transformed from the monetite coatings produced by the induction heating method on HT-C/C composites.     

时效状态对挤压铸造(Al2O3f+Cf)/ZL109混杂复合材料耐磨性能的影响

利用挤压铸造法制备了(Al2O3f Cf)/ZL109混杂复合材料,研究了时效状态对该混杂复合材料耐磨性能的影响.结果表明:(Al2O3f Cf)/ZL109混杂复合材料在峰时效阶段及过时效初期具有较佳的耐磨性能,而在该阶段以后,磨损表面大量脆性剥落坑的产生导致复合材料耐磨性降低.     

Electrochemical corrosion and bioactivity of titanium–hydroxyapatite composites prepared by spark plasma sintering

The corrosion resistance and bioactivity of titanium–hydroxyapatite (Ti–HA) composites prepared by mechanical alloying (MA) followed by spark plasma sintering were investigated. Potentiodynamic polarization tests showed that Ti composites containing 0–10% HA exhibited higher corrosion resistance than commercially pure Ti. An increase in HA concentration (20–30%) decreased corrosion resistance owing to the craterlike defects induced by ceramic particle detachment. Increasing MA time significantly reduced defect density and improved corrosion resistance. Bioactivity test on Ti HA composites in simulated body fluid revealed the growth of a nano-HA layer, which indicates the high potential of Ti–HA composites for application in biomedical implants.     

Nanostructural Characteristics of Vacuum Cold-Sprayed Hydroxyapatite/Graphene-Nanosheet Coatings for Biomedical Applications

Development of novel biocompatible nanomaterials has provided insights into their potential biomedical applications. Bulk fabrication of the nanomaterials in the form of coatings remains challenging. Here, we report hydroxyapatite (HA)/graphene-nanosheet (GN) composite coatings deposited by vacuum cold spray (VCS). Significant shape changes of HA nanograins during the coating deposition were revealed. The nanostructural features of HA together with curvature alternation of GN gave rise to dense structures. Based on the microstructural characterization, a structure model was proposed to elucidate the nanostructural characteristics of the HA-GN nanocomposites. Results also showed that addition of GN significantly enhanced fracture toughness and elastic modulus of the HA-based coatings, which is presumably accounted for by crack bridging offered by GN in the composites. The VCS HA-GN coatings show potential for biomedical applications for the repair or replacement of hard tissues.