纯镁超声微弧氧化生物涂层植入体内4周的降解行为

研究纯镁及其超声微弧氧化生物涂层种植体植入动物股骨干内的短期降解过程。利用电化学工作站测定试样在模拟体液中极化曲线。术后4周,取兔股骨干的组织进行扫描电镜观察(SEM)及锥形束检测(CBCT)观察种植体降解状况。结果表明,纯镁与超声微弧氧化生物涂层都发生了降解,在骨组织表面及镁基体的表面几乎同时发生反应,在金属-骨界面形成紧密相邻的降解层、新生骨层,并可见少量的不连续的纤维结缔组织,超声微弧氧化镁生物涂层的腐蚀降解速率及对周围骨组织的刺激明显小于纯镁基体。纯镁基体及超声微弧氧化涂层试样周围的骨组织变化符合正常骨组织的愈合过程,超声微弧氧化生物涂层显示出更好的生物相容性及降解性。     

HA/316L粉非对称生物FGM的微观组织与增韧机制

采用热压工艺制备了HA／316L粉非对称生物功能梯度材料（FGM）。HA／316L粉非对称生物FGM在宏观上呈现明显的梯度,微观上则表现出成分连续变化,且各成分分布均匀、弥散。在各梯度层内部及界面都没有裂纹及大孔洞出现,界面结合紧密。随着316L粉的含量增加,韧窝的数量逐渐增加,韧窝形貌由浅变深,边缘由尖锐逐渐变得圆滑,表明材料由脆性断裂向韧性断裂转化。纯HA梯度层为典型的脆性断裂,HA80／316L和HA60／316L梯度层表现为典型的晶间断裂,HA40／316L和HA20／316L梯度层断裂性质为晶间断裂中掺杂有韧性断裂,而316L梯度层则表现为典型的韧性断裂。316L粉的加入改变了HA／316L粉生物FGM各梯度层的断裂方式,从而提高了材料的力学性能。从整体上而言,HA／316L粉生物FGM主要增韧机制包括层间裂纹偏转增韧与裂纹偏转增韧。     

Ti/Cu/Ti火焰加热扩散钎焊界面组织分析

用保护膜防护，并施加一定压力可实现Ti／Cu／Ti氧-乙炔焰加热扩散钎焊。通过BSE(背散射电子衍射)、EDS(电镜线扫描)、拉伸试验等测试手段对Ti／Cu／Ti钎焊接头组织、成分及结合强度测定的结果表明，在试验温度下，接头中Cu、Ti之间发生了剧烈的扩散。加热温度为840-870℃时，钎缝界面中部组织由Cu4Ti与Cu(Tj)固溶体组成，结合强度较高。加热温度为870-900℃时，钎缝界面中部组织由CuTi与Cu4Ti Cu(Ti)固溶体组成，结合强度较低。钎焊结合强度与加热温度相关。     

稀土掺杂纳米相增强Ti-HA复合材料研究进展

钛(Ti)及其合金由于其良好的生物力学性能和生物化学性能,已经成为高负荷骨骼较好的替代材料。可是钛合金与骨组织弹性模量不匹配,容易造成应力屏蔽。而羟基磷灰石(HA)是自然骨无机质的主要成分,具有良好的生物活性和生物相容性,但是却因强度低、脆性大,不能用在承载部位而限制了应用。在Ti/HA复合材料的制备方法和基本性能研究现状基础上,从纳米相增强和稀土掺杂等方面综述了Ti/HA复合材料的发展现状。     

种植体用钛涂层不锈钢的研究

本研究采用低压等离子喷涂工艺，在317L不锈钢基体上喷涂了钛涂层，制备出钛涂层的种植体。通过动物的植入实验，研究了这种种植体的生物相容性；并综合利用扫描电镜、电子探针、X射线衍射仪等分析仪器对涂层的微观结构、涂层—基体界面成分分布等进行了研究；同时也对涂层种植体的电化学性能进行了研究。结果表明，喷涂过程对不锈钢基体本身的力学性能影响很小；钛涂层结合良好，其与骨组织的生物相容性能优于未涂钛涂层的。     

生物植体表面活化改性(英文)

研究目标是建立通用的纳米级表面涂层技术, 修改粗糙的钛表面化学牙种植体,同时保持微米级水平的表面形貌。以表面形貌调控表面化学,可能会引起生物活性、加速植入种植体表面的整合、缩短移植后的愈合时间。羟基磷灰石(HA)具有生物相容性和骨传导材料特点,HA 涂层具有促进骨骼生长的优点,但涂层易脱落,有混合晶相弊端。本文介绍了凯美特(Chemat)公司的一项新技术(BioFun),即设计一种新型室温自组装,在粗糙度为微米级水平的植体表面来制备纳米级促进骨生长表面。表面经过发射扫描电镜,X 射线光电子能谱,EDS 和 SMM 分析得到表征。生物相容性和生物植入物的表面活性研究在动物体外和体内进行。在动物体外,大鼠骨髓基质干细胞培养试验表明新型植体表面技术是生物相容的,也是无毒的。纳米羟基磷灰石植入已通过官能 10993 生物相容性面板测试。实验植入物或无 HA 纳米粒子的手术放置在植入大鼠股骨和推入式测试后 2 个星期愈合。这些数据表明,HA 纳米粒子沉积加速早期骨整合的过程,可能增加其剪切粘结强度。总之,BioFun 技术可创建一个纳米尺度的成骨表面,HA 纳米颗粒沉积并没有改变钛基板的预期微观形貌,而创造了新的纳米级...     

酸碱刻蚀电沉积钛基HA涂层及其与牛血清白蛋白的相互作用

利用酸碱刻蚀两步化学法对Ti进行活化处理,经水热电沉积制备Ti/羟基磷灰石涂层(HA),用SEM,XRD,FTIR和EDS对涂层进行分析和表征,用微控电子万能试验机对基体和涂层的界面结合强度进行测试,将涂层在牛血清白蛋白溶液(BSA)中浸泡2 h～3 d后,分析涂层与BSA溶液的FTIR和XSP光谱.结果表明:活化处理后的Ti表面形成了活性TiO2过渡层,活化过渡层使涂层与基体的结合强度显著提高;涂层形貌、元素比例与骨组织纤维相一致.涂层与BSA作用后的FTIR光谱表明,在涂层中引入了BSA酰胺带基团,在BSA溶液中又出现HA中PO43-基团,蛋白质酰胺Ⅰ带、酰胺Ⅱ带和HA中PO43-的红外光谱的位置和谱峰均发生变化,由此推测了Ti/HA涂层与BSA间的作用机制,指出:正是由于Ti/HA涂层与BSA间的相互作用使涂层得以在蛋白质结构中交互有序地排列生长,这是Ti/HA涂层具有生物相容性的基础.     

Al／Ti／Al复合层原位生成金属间化合物连接陶瓷

用Al／Ti／Al复合层作连接材料，通过连接温度下原位生成金属间化合物真空连接Si3N4陶瓷。研究了Al与Ti的厚度匹配和工艺参数对接头显微组织及其强度的影响和接头的形成过程。结果表明：当原位生成的连接层金属组织为Al3Ti／Ti／Al3Ti时，由于纯金属间化合物Al3Ti脆性大，且其与剩余Ti片的结合强度低，陶瓷接头强度低；当连接层金属组织为大量Al3Ti颗粒加少量Al基固溶体时，连接层金属能获得良好的强化效果，与用纯Al连接的接头相比，接头室温和高温强度显著提高。Al与Ti的厚度匹配和连接参数适当时，接头室温和600℃剪切强度可分别达到89．4MPa和29．7MPa。     

ZrSiN-HA涂层应用于纯钛种植体的实验研究

采用等离子喷涂技术在纯钛表面制备氮硅锆-羟基磷灰石(ZrSiN-HA)复合涂层并植入实验动物下颌骨.利用扫描电镜、电子万能材料试验机对比检测ZrSiN-HA、ZrSiN、HA与纯钛对照4组涂层的骨结合力,观测各组断裂区域的形貌,并分析复合涂层的表面形貌;用电化学腐蚀测试系统对比检测4组涂层的耐腐蚀性.试验结果表明,种植体表面喷涂ZrSiN-HA后较单纯喷涂HA的表面更加致密,结晶化明显;ZrSiN-HA涂层与其他涂层相比骨结合力最高,耐腐蚀性能最强.ZrSiN-HA涂层的应用有利于种植体的长期固位,可以应用于人体,对齿科修复体具有巨大的潜在应用价值.     

纯钛表面聚吡咯涂层的制备及其对成骨细胞生长的影响

采用水溶液恒电流电化学聚合法在纯钛表面制备了PPy涂层（Ti／PPy）。利用傅里叶红外光谱、X射线光电子能谱测定表面化学成分。用扫描电子显微镜观察涂层微观形貌，接触角测量仪检测接触角并计算表面能。搭接剪切法测定涂层与基底间的结合强度。通过对成骨细胞在Ti／PPy表面附着、铺展以及增殖能力的检测，评价Ti／PPy对成骨细胞生长的影响。结果表明，Ti／PPy的表面能（59．5mJ／m^2）高于纯钛（47．0mJ／m^2），并且具有良好的结合强度（9．16±1．62）MPa。Ti／PPy与Ti一样具有良好的生物相容性，成骨细胞能够在Ti／PPy涂层表面完成附着、铺展以及增殖的生物功能。     

Preparation of Biodegradable Mg/β-TCP Biofunctional Gradient Materials by Friction Stir Processing and Pulse Reverse Current Electrodeposition

Mg alloys, as a new generation of biodegradable bone implant materials, are facing two tremendous challenges of enhancing strength and reducing degradation rate in physiological environment to meet clinical needs. In this study, tricalcium phosphate(β-TCP) particles were dispersed in Mg–2 Zn–0.46 Y–0.5 Nd alloy by friction stir processing(FSP) to produce Mg-based functional gradient materials(Mg/β-TCP FGM). On the surface of Mg/β-TCP FGM, the hydroxyapatite(HA) coating was prepared by electrodeposition. The effects of FSP and electrochemical parameter on the microstructure, microhardness, bonding strength and corrosion performance of the Mg/β-TCP FGM were investigated. After four passes of FSP, a uniform and fine-grained structure was formed in Mg/β-TCP and the microhardness increased from 47.9 to 76.3 HV. Compared to the samples without β-TCP, the bonding strength of the Mg/β-TCP FGM increased from 23.1 ± 0.462 to 26.3 ± 0.526 MPa and the addition of degradable β-TCP contributed to the in situ growth of HA coating. The thickness of HA coating could be dominated by controlling the parameters of electrodeposition. According to the results of immersion tests and electrochemical tests in simulated body fluid, it indicated that the degradation rate of the Mg/β-TCP FGM could be adjusted.     

PLASMA SPRAYED Ti AND HA COATINGS： A COMPARATIVE STUDY BETWEEN APS AND VPS

Titanium (Ti) and hydroxyapatite (HA) coatings have been prepared via air (APS) and vacuum plasma spraying (VPS), and then their composition, structure, bonding strength and bioactivity were examined. The results obtained reveal that in APS process many of Ti were oxidized, but in VPS the oxidization was avoided. VPS Ti coating possesses better bonding condition than APS Ti coating. As for HA coating, higher crystallinity has been obtained while the coating was deposited by VPS as compared with APS. The simulated body fluid (SBF) tests show that both of APS and VPS HA coatings possess good bioactivity. As compared with APS, VPS is recommended as a better method to deposit Ti and HA coatings that can be applied as hard tissue replacement implants.     

Studies on the thermal spraying of apatite bioceramics

Hydroxylapatite (HA) coatings on metal substrates have been investigated for many years. These coatings have proved to be compatible with bone. The degree of crystallinity of HA changed, and sometimes dissociation was observed with respect to the plasma spray process. However, the plasma spray process hardly altered the crystallographic structure, with only line broadening visible. Thein vitro solubility is dependent on the degree of crystallinity of the coating. Tensile strength measurements on the strength of the coating-substrate interface using various adhesives revealed a significant difference between epoxy resin and methacrylate. The failure mode of this tensile test was dependent on the coating thickness and surface texture (polished versus nonpolished). In animal studies, the fixation of hydroxylapatite plasma- spray coated cylinders as well as noncoated Ti- 6A1- 4V cylinders (Ti) in cortical bone was evaluated using pushout tests. It appeared that HA- coated implants showed higher push- out strengths in the first months than the titanium implants, because of the earlier bone formation against the HA coating.     

钛/铝/镁爆炸焊复合板波形界面及力学性能

文中提出以薄的铝合金板作为过渡层,采用爆炸焊接技术成功制备钛/铝/镁层状复合材料. 对钛/铝接合界面、铝/镁接合界面及钛/铝/镁爆炸复合板的整体力学性能进行了分析研究. OM和SEM试验结果表明,钛/铝接合界面和铝/镁接合界面均为波状接合界面,在铝/镁界面出现了局部熔化区;钛/铝接合界面为小尺寸波(λ=160 μm,h=26 μm),铝/镁接合界面为大尺寸波(λ=1 740 μm,h=406 μm);拉-剪试验表明,复合板沿着铝/镁接合界面断裂;弯曲性能测试表明,钛板一侧受拉时复合板弯曲强度和塑性均优于镁合金板一侧受拉,断裂始于铝/镁接合界面,最终从镁合金板一侧剪切断裂失效.     

Microstructure of titanium component in hydroxyapatite-Ti asymmetrical functionally graded biomaterial

The microstructure of the titanium component in hydroxyapatite (HA)-Ti asymmetrical functionally graded biomaterial (FGM) fabricated by powder metallurgical process was investigated. It is found that the main substructure of the Ti component in the FGM consists of screw dislocations whose Burgers vectors are 1/3(1150) and there are not deformation twins. Screw dislocations are straight and regularly distributed, and cross slip can be observed. The density of the dislocations in the Ti component increases with the rise of the content of the HA component in the FGM. The subgrain boundaries of the Ti component consist of dislocation network walls. Some microbands with bamboo-leaf-shape distribute regularly in Ti grains, which exhibit a specific orientation relationship witha α-Ti parent phase.     

SiC/TiAl扩散连接接头的界面结构及连接强度

对常压烧结的ＳｉＣ陶瓷与ＴｉＡｌ金属间化合物进行了真空扩散连接。采用扫描电镜、电子和Ｘ射线衍射分析等确定了反应产物的种类和接头的界面结构,并用拉剪试验评价了接头的连接强度。研究结果表明：ＳｉＣ与ＴｉＡｌ扩散连接中生成了ＴｉＡｌ２、ＴｉＣ和Ｔ５Ｓｉ３Ｃｘ三种上,接头的界面结构为ＳｉＣ／ＴｉＣ／（ＴｉＣ＋Ｔｉ５Ｓｉ３Ｃｘ）／ＴｉＡｌ。在１５７３Ｋ和１．８ｋｓ的连接条件下,接头室温剪强度达到２４０ＭＰａ     

钛合金与不锈钢超塑性扩散连接工艺及机理研究

基于微细晶超塑性扩散连接方法,对TC4钛合金与1Cr18Ni9Ti不锈钢成功实现了直接扩散连接,系统分析了接头性能、界面微观结构及超塑性扩散连接机理。结果发现：TC4钛合金与1Cr18Ni9Ti奥氏体不锈钢直接超塑性扩散连接时,较佳连接工艺规范为：温度T=760~820 ℃,压力p=6~9 MPa,时间t=20~40 min;接头剪切强度τ＝125.3~148.7 MPa。与一般直接扩散连接相比,连接温度降低了约100 ℃,接头的剪切强度提高了1倍以上,且连接试样无明显变形。细化热处理TC4钛合金与1Cr18Ni9Ti不锈钢超塑性扩散连接时,其接头的形成过程大致可分为3个阶段：形成紧密接触阶段、接触表面激活阶段及靠近活化中心的界面冶金结合区形成阶段。     

铝合金等离子体基离子注入氮／钛层的结构

用X射线光电子能谱（XPS）和小掠射角X射线衍射（GXRD）研究了铝合LY12等离子体基离子注入氮／钛改性层的结构。结果表明。氮在注入层呈高斯分布,而钛沿注入方向逐渐减少。钛的注入对已注入的氮的分布有重要影响。钛的等离子体密度直接影响钛在改性层中的成分、相结构。改性层主要由TiO2,Al2O3,Aln,TiAl3,TiN或Ti组成。     

Microstructures and mechanical properties of titanium/biodegradable-polymer FGM for bone tissue fabricated by spark plasma sintering method

Ti and Ti alloys are widely used as metallic implants, because of their good mechanical properties and nontoxic behavior. However, they have problems as the implant-materials, namely, high Young's modulus comparing that of bone and low bonding ability with bone. There is a need to develop the Ti and Ti alloys with lower Young's modulus and good bonding ability. In previous study, Ti composite containing biodegradable poly-l-lactic-acid (PLLA) fiber has been fabricated to improve these problems. However, this composite has low strength because of the imperfect sintering of Ti matrix. To improve its strength, sintering of Ti matrix should be completed. In this study, Ti–NaCl composite material was fabricated by spark plasma sintering (SPS) method using powder mixture of Ti and NaCl to complete the sintering of Ti matrix. To obtain porous Ti samples, Ti–NaCl composite were put into hot water of 317 K. The porous Ti was dipped into PLLA melt in order to introduce PLLA into the pores of porous Ti. Finally, Ti/PLLA composite was obtained, and PLLA plays a role as reinforcement of Ti matrix. It was found that the Ti/PLLA composite has gradient structure and mechanical properties.     

Selective laser melting of a stainless steel and hydroxyapatite composite for load-bearing implant development

Selective laser melting (SLM) is emerged as a new manufacturing technique to directly fabricate customised implants using metallic materials. This technique is also capable of processing powder mixtures to generate advanced composites offering desirable properties. In this research, the SLM technique was used to directly fabricate hydroxyapatite (HA) and 316L stainless steel (SS) powders mixture with an objective to develop load-bearing and bioactive implants. SLM processing parameters were identified to fabricate pure SS and SS/HA composite specimens. The visual inspections, density measurements, tensile and hardness tests, and microstructural examinations was conducted to illustrate the effect of SLM parameters and HA particles on the properties of SS/HA composites. It was found that the incorporation of HA particles influenced SLM processing parameters including laser power, scanning speed and scanning procedure. A duplication of scanning procedure was necessary to avoid the balling effects and to form well joined SS/HA composite layer. The highest tensile strength of SS/HA parts produced at optimum processing parameters was close to human bone tensile strength and adequate for load-bearing bone implants. Moreover, the SS/HA part had a finer grain size than that of the SS attributed to the HA particles as nuclei to assist heterogeneous nucleation. These finer grains enhanced the hardness of the SS/HA part.