钛合金表面等离子喷涂涂层材料的研究进展

介绍了钛及钛合金表面等离子喷涂涂层材料的研究进展,主要从钛合金表面等离子喷涂陶瓷材料耐磨涂层、固体润滑减摩涂层、生物活性涂层、功能涂层等几方面进行了简要的介绍。并对钛及钛合金表面等离子喷涂涂层材料的发展趋势进行了展望。     

医用材料聚醚醚酮等离子喷涂表面改性研究进展

聚醚醚酮材料(PEEK)具有良好的生物相容性、化学稳定性、X射线可穿透性及优异的力学性能,广泛用于创伤、脊柱和关节等生物医疗领域。然而,PEEK属于生物惰性材料,其骨整合性不足,这在一定程度上限制了该材料在骨修复与替换等领域的发展和应用。等离子喷涂技术由于工艺简单、经济,喷涂涂层的黏结强度高等特点,是解决聚醚醚酮材料骨整合能力不足的重要表面涂层改性技术。首先,简述了等离子喷涂工艺的涂层沉积机理,并分别对等离子喷涂钛以及羟基磷灰石两种常用涂层进行了介绍;其次,从不同喷涂工艺以及喷涂参数对涂层的影响出发,详细介绍了近几年对PEEK基等离子喷涂涂层的结合强度等机械性能的最新研究进展,并对等离子喷涂过程对PEEK基体的机械强度、疲劳强度、热性能和化学降解等初始性能影响进行了总结与评价,详细介绍了PEEK基等离子喷涂涂层体内外生物性能的最新研究进展;最后,展望了等离子喷涂改性PEEK基材料的临床应用前景,以期为未来设计新型PEEK基生物材料提供理论指导。     

等离子喷涂技术在骨科植入物表面改性的应用

从生物陶瓷涂层材料、常用等离子喷涂工艺、工艺参数对生物陶瓷涂层物化性能的影响等几个方面探讨了等离子喷涂技术在骨科植入物表面改性的应用,并对等离子喷涂技术在未来植入物表面改性的研究进行了展望。     

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.     

等离子喷涂技术在骨植入体表面改性中的研究进展

金属植入体材料已广泛用于各种硬组织相关疾病的治疗,但金属植入体表面的骨整合和抗菌能力不足,往往导致临床植入手术失败。表面改性能够在保持金属材料优异力学性能的同时,针对性地改善其表面特性,目前广泛用于解决金属植入体存在的骨整合能力差和缺乏抗菌性能等问题。在众多表面改性技术中,等离子喷涂因性价比高、工艺成熟、原料可选择范围广及可大规模生产等优点,目前已在人工关节和牙种植体表面改性方面获得商业化应用。从提高植入体成骨活性、抗感染能力及骨免疫调节能力等方面介绍等离子喷涂技术的优势及其在金属植入体表面改性方面的研究进展,阐述等离子喷涂技术在优化骨科植入体表面化学性质方面的优势,并重点讨论等离子喷涂技术在制备和调控植入体表面纳米结构方面的潜在应用价值,为植入体表面设计提供借鉴。还结合课题组前期在等离子喷涂技术领域的相关工作,提出关于等离子喷涂技术在骨植入体表面改性方面的新思路。     

生体用钛材/羟基磷灰石涂层接合面的研究

钛材与其他金属系生体材料相比 ,钛材与生体骨骼的力学相容性显著较好 ,但因其表面无新生骨生成以致与原有生体骨的接合强度并不理想。因此 ,为了能在钛材上产生新生骨可对其表面采取近生体成分的涂层处理 ,这种涂层要求具有接近于骨质的成分 ,最典型的便是羟基磷灰石 (Ｃａ10 (ＰＯ4 ) 6 (ＯＨ) 2 ,缩写为ＨＡｐ)。为此 ,研究了ＨＡｐ涂层与钛材基体的接合性能及其结晶学关系。实验研究时采用了等离子喷涂技术 ,在钛材人造牙根 (15ｍｍ× 5ｍｍ)表面喷涂ＨＡｐ涂层后 ,采用Ｘ射线衍射、透射电镜、扫描电镜、光学显微镜等研究手段 ,对ＨＡ…     

等离子喷涂灰铸铁涂层的研究进展

在汽车上使用轻质铝合金发动机可以有效减少燃油消耗和环境污染,但铝合金的耐磨损性能较差,从而造成发动机工作过程中气缸壁面容易磨损。利用表面改性技术对铝合金表面进行强化处理,可以满足其作为滑动部件在高载荷条件下的使用要求。灰铸铁较低的成本和其中石墨的自润滑作用,使其成为铝合金发动机气缸表面保护涂层材料的首选。等离子喷涂技术以其高效率和灵活性在表面强化领域受到广泛应用。因此,利用等离子喷涂制备灰铸铁涂层成为改善铝合金发动机气缸表面耐磨性的有效方法之一。但是,由于等离子喷涂过程中熔滴冷却速度极快,等离子喷涂很难得到含大量石墨组织的灰铸铁涂层。以调控灰铸铁涂层中的石墨含量为目的,总结了等离子喷涂灰铸铁涂层的研究现状,以及基体温度、颗粒尺寸、添加合金元素等对熔滴冷却速度的影响,并以此为基础,结合凝固理论分析了在涂层中保留灰铸铁粉末中的石墨组织的可行性,同时分析了在铸铁涂层中保留石墨所面临的主要问题,并提出了解决这些问题的主要措施。最后就在等离子喷涂灰铸铁涂层中保留石墨的研究方向进行了展望。     

金属喷涂、堆焊与修复——金属喷涂工艺与设备

热喷涂纳米结构热障涂层的最新研究;渗铝及扩散处理对电弧喷涂层结合强度的影响;高速电弧喷涂3Cr13钢涂层的组织及在含细沙油润滑条件下的磨损性能;锌合金快速模具表面改性技术;过渡材料对等离子喷涂Al2O3梯度陶瓷涂层性能影响     

等离子喷涂制备吸波涂层及等离子渗碳技术研究现状

随着雷达探测技术的发展，对装备的隐身性能也提出越来越严苛的要求，隐身技术可显著提高军事装备及军人的生存能力，提升战斗效率，取得更大的战场控制权。传统吸波涂层的制备方法工艺复杂且效率低下，作为一种热喷涂技术，由于等离子喷涂具有工艺简单、适用范围广、可操控性和可调控性高等优点，在制备吸波涂层中得到广泛应用。材料表面状态对其性能有着重要的影响，等离子渗碳同样作为一种表面处理工艺，对提高材料表面强度、耐磨性等具有重要作用。介绍了等离子喷涂的基本原理以及送粉速率、输出功率、喷涂距离、喷涂速度等涂层制备基本工艺参数对涂层的影响。研究表明，送粉速率相同时，喷涂功率过大或过小均会导致涂层质量下降；喷涂距离过小会导致涂层与基体的结合力降低，而距离过大又会降低喷涂效率和涂层密度，合理调控等离子喷涂的工艺参数对涂层质量的好坏有着直接且重要的影响。总结了近年来等离子喷涂制备吸波涂层方面的研究成果，介绍了传统渗碳热处理技术与新型渗碳热处理技术的发展，概述了等离子渗碳的发展和现状，可知加工时间及加热温度对渗碳层的性能产生了较大影响。对以上两种表面改性技术未来的研究发展进行了展望， 为航空航天、军事装备等涉及关键零部件表面改性方面提供一定的参考价值。     

等离子喷涂生物涂层对病理性骨缺损愈合的应用研究

患者代谢性疾病(如骨质疏松症、糖尿病、痛风等)不利于体内骨植入体与周围骨的结合。基于不同疾病患者骨折部位骨微环境的特点,采用等离子喷涂技术制备的抗氧化应激生物涂层(针对骨质疏松)、抗感染-促成骨功能的生物涂层(针对糖尿病)和骨免疫调控涂层(针对痛风)能提高骨科植入器械与骨组织接触界面处的成骨能力,是增强植入体与骨结合的有效方法。研究了骨植入生物涂层对不同病理状态下效应细胞的影响,总结了材料表面性质调控效应细胞行为以及骨形成的规律,可为新型骨植入生物涂层的设计提供依据。等离子喷涂技术制备的含氧化铈的生物抗氧化涂层,可催化分解生物体内的过量活性氧簇,保护骨细胞成骨分化能力免于氧化应激的负面影响,有利于提高骨质疏松症下骨植入体的愈合能力。具抗感染与促成骨功能的硅酸钙基生物涂层能够抑制细菌在其表面的粘附与生长,降低植入体相关感染的几率,另外,该类涂层还能促进骨细胞成骨分化与矿化,提高骨植入体的成骨能力,有望应用于骨折合并糖尿病患者。等离子喷涂钛涂层表面微纳多级结构的构建以及生物涂层中锶/硼/铈等元素的掺入,有利于提高骨免疫性能,并促进骨细胞成骨分化,可用作炎症疾病下的骨缺损修复材料。     

Characterization of thermal sprayed hydroxyapatite powders and coatings

Calcium phosphate materials such as hydroxyapatite (HA) have biocompatible properties that can promote osteogenesis or new bone formation. Thermal spraying is an economical and effective process for coating the hydroxyapatite onto metal. It has been reported that plasma spraying changes the degree of crystallinity as well as the phase composition of the HA. This article reports the preparation and characterization of HA powders and coatings by two thermal spray processes (plasma and combustion flame) and suggests that the state of the starting powder adversely affects the coating characteristics. The raw HA powders are synthesized through a chemical reaction involving calcium hydroxide and orthophosphoric acid. Phase analysis using an X- ray diffractometer revealed that the synthesized powder consists of predominantly the HA phase. Calcined and crushed HA powders of various size ranges were fed into the plasma jet to produce HA coatings on metallic substrates. In addition, some HA powders were sprayed into distilled water by plasma spraying and combustion flame spraying to study powder melting characteristics. Other samples were plasma sprayed onto a solid rotating target to study atomization and impact behavior. The morphology of the rapidly solidified powders and thermal sprayed coatings were examined by scanning electron microscopy (SEM). An X- ray sedimentation particle size analyzer, laser diffraction particle size analyzer, and image analyzer performed the particle size analysis. Preliminary results indicate that particle cohesion, size range, and thermal treatment in the plasma affect the phase and structure of the as- sprayed coating, and some post- spray treatment may be necessary to produce a dense and adherent coating with the desired biocompatible properties.     

Hydroxyapatite coatings for biomedical applications deposited by different thermal spray techniques

Thermally sprayed hydroxyapatite (HAp) coatings are widely used for various biomedical applications due to the fact that HAp is a bioactive, osteoconductive material capable of forming a direct and firm biological fixation with surrounding bone tissue.Bioceramic coatings based on nanoscale HAp suspension and microscale HAp powder were thermally sprayed on Ti plates by high-velocity suspension flame spraying (HVSFS) technique and atmospheric plasma spraying (APS) as well as high velocity oxy fuel spraying (HVOF) technique. HVSFS is a novel thermal spray process developed at IMTCCC, for direct processing of submicron and nano-sized particles dispersed in a liquid feedstock.The deposited coatings were mechanically characterized including surface roughness, micro hardness and coating porosity. The bond strength of the layer composites were analyzed by the pull-off method and compared for the different spray techniques. Phase content and crystallinity of the coatings were evaluated using X-ray diffraction (XRD). The coating composite specimen and initial feedstock were further analysed by scanning electron microscope (SEM) and rheology analysis.     

An investigation on plasma spraying with artificial bone powder and bonding characteristics of coating

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钛合金表面激光熔覆制备羟基磷灰石生物陶瓷涂层的研究现状

利用激光熔覆技术在医用钛金属表面制备生物活性陶瓷羟基磷灰石(HAP)涂层,是近年来世界各国生物医用植入材料及相关领域的研究热点之一。首先简要概括了HAP生物陶瓷涂层材料的特点与意义,介绍了医用钛金属材料与生物陶瓷材料的历史发展与特点,指出了已有技术制备的生物陶瓷涂层在制备与应用中存在的优缺点,介绍了激光熔覆制备生物陶瓷涂层的特点与优点。综述了国内外钛及钛合金表面激光熔覆制备HAP生物陶瓷涂层、激光快速成形生物陶瓷涂层及相关材料的研究特点、现状与进展。重点介绍了激光熔覆不同成分原材料、添加稀土成分与不同波长激光制备生物陶瓷涂层的机理,及激光熔覆制备生物陶瓷涂层的特点与优缺点。激光熔覆制备生物陶瓷涂层及相关材料是一个多学科交叉的研究领域,通过对钛合金的激光表面改性,激光熔覆制备生物陶瓷涂层在理论研究与临床应用上具有广阔的前景。最后对激光熔覆工艺制备合成HAP生物陶瓷涂层未来的研究方向进行了讨论与展望。     

High-velocity oxyfuel thermal spray coatings for biomedical applications

Plasma spraying is used to produce most commercially available bioceramic coatings for dental implants; however, these coatings still contain some inadequacies. Two types of coatings produced by the high- velocity oxyfuel (HVOF) combustion spray process using commercially available hydroxyapatite (HA) and fluorapatite (FA) powders sprayed onto titanium were characterized to determine whether this relatively new coating process can be applied to bioceramic coatings. Diffuse reflectance Fourier transform infrared (FTIR) spectroscopy, x- ray diffraction (XRD), and scanning electron microscopy (SEM) were used to characterize the composition, microstructure, and morphology of the coatings. The XRD and FTIR techniques revealed an apatitic structure for both HA and FA coatings. However, XRD patterns indicated some loss in crystallinity of the coatings due to the spraying process. Results from FTIR showed a loss in the intensity of the OH^∼ and F^∼ groups due to HVOF spraying; the phosphate groups, however, were still present. Analysis by SEM showed a coating morphology similar to that obtained with plasma spraying, with complete coverage of the titanium substrate. Interfacial SEM studies revealed an excellent coating-to-substrate apposition. These results indicate that with further optimization the HVOF thermal spray process may offer another method for producing bioceramic coatings.     

冷喷涂技术在生物医学领域中的应用及展望

冷喷涂技术(cold spray technology)是一类赋予材料表面特殊性能的重要手段。概述了冷喷涂技术在制备温度敏感生物材料加工领域的优势,并重点综述了利用冷喷涂技术制备的典型生物材料。目前,冷喷涂沉积永久性植入金属材料,如Ti合金、Fe基合金、Co-Cr合金和可降解金属材料Mg合金等技术相对成熟。近年来随着冷喷涂技术的发展,有效解决和拓展了用于医疗器械表面改性的涂层材料体系,如冷喷涂制备高分子材料超高分子量聚乙烯(UHMWPE)涂层,以及高密度聚乙烯(HDPE)和聚醚醚酮(PEEK)表面冷喷涂制备生物涂层。最值得关注的冷喷涂或真空冷喷涂技术制备陶瓷涂层,如羟基磷灰石(HA)、羟基磷灰石-石墨烯(HA-graphene)以及二氧化钛(Ti O2),在生物医学领域应用具有突破性进展。同时归纳了冷喷涂技术在生物医学领域的研究现状和问题,虽然在针对冷喷涂生物涂层的微观结构、力学行为、腐蚀抗力等方面取得了一定成果,在组织工程、抗菌材料等领域也取得了尝试性突破,但尚缺乏系统的冷喷涂涂层生物学性能表征,涂层与细胞/组织相互作用机理还不明确,相关的临床研究欠缺。最后,在此基础上,展望了未来生物材料朝功能化和个性化医疗方向的发展方向。冷喷涂技术在功能化载药涂层的低温制备和个性化医疗器械增材制造等领域将有更大的应用空间,并给新型生物材料的表面改性带来更多机遇和可能。     

Preparation and cell-materials interactions of plasma sprayed strontium-containing hydroxyapatite coating

The use of strontium-containing hydroxyapatite (Sr-HA) as a biomaterial has been reported recently. In vitro and in vivo studies have shown that Sr-HA promotes osteoblast response and stimulates new bone formation. In order to extend its usage to major load-bearing applications, such as artificial hip replacement, it has been proposed that the material could be used in the form of a coating on implant surfaces. This paper reports a preliminary study of biocompatibility of plasma sprayed Sr-HA coatings on a metallic substrate. Coatings of Sr-HA containing 10 mol% Sr²⁺ was produced on titanium alloy substrates. The coating exhibited good bonding with the substrate. The bioactivity of Sr-HA coating was evaluated in vitro by immersion in simulated body fluid (SBF). After immersion in SBF, Sr-HA coating exhibited great ability to induce apatite precipitation on its surface. The possible effects of cell-materials interactions of Sr-HA coating were examined by culturing osteoprecursor cells (OPC1) on coating surfaces. The effect of Sr-HA was also compared to a hydroxyapatite (HA) coating, which is widely used in orthopedics and dentistry. The results indicated that Sr-HA coating had good biocompatibility with human osteoblasts. OPC1 cells survived and proliferated well on the surface of coating. Sr-HA coating promoted OPC1 cells attachment, and more local contacts were produced on the surface. The presence of Sr stimulated OPC1 cell differentiation and ALP expression. No deleterious effect on ECM formation and mineralization was found with Sr-HA coating. The results indicated that Sr-HA coating had good mechanical properties and bioactivity in vitro.     

Advanced Microstructural Study of Suspension Plasma Sprayed Hydroxyapatite Coatings

Fine, home-synthesized, hydroxyapatite powder was formulated with water and alcohol to obtain a suspension used to plasma spray coatings onto a titanium substrate. The deposition process was optimized using statistical design of 2 ⁿ experiments with two variables: spray distance and electric power input to plasma. X-ray diffraction (XRD) was used to determine quantitatively the phase composition of obtained deposits. Raman microscopy and electron probe microanalysis (EPMA) enabled localization of the phases in different positions of the coating cross sections. Transmission electron microscopic (TEM) study associated with energy-dispersive x-ray spectroscopy (EDS) enabled visualization and analysis of a two-zone microstructure. One zone contained crystals of hydroxyapatite, tetracalcium phosphate, and a phase rich in calcium oxide. This zone included lamellas, usually observed in thermally sprayed coatings. The other zone contained fine hydroxyapatite grains that correspond to nanometric and submicrometric solids from the suspension that were agglomerated and sintered in the cold regions of plasma jet and on the substrate.