【作者】 逯峙；

【导师】 刘咏；

【作者基本信息】 中南大学 ， 材料科学与工程， 2013， 博士

【摘要】 玻璃陶瓷具有较高的力学性能、较好的耐磨性和化学稳定性等,在建筑、电子工业、航空航天、医学等领域有着广阔的发展前景。由于玻璃陶瓷主要以SiO2、MgO、Al2O3等氧化物为原料,原料来源广泛,并且在生产和使用过程中能耗和污染较小,因此近年来得到了广泛的研究开发和生产。其中氟金云母／氟磷灰石玻璃陶瓷有较好的可加工性能、生物活性和生物相容性,在牙科和骨科修复领域具备较大的应用潜力,同时,用于牙科和骨科修复领域时,通常要求材料具备良好的力学性能和摩擦磨损性能,使其既有承担一定静载荷的能力,又具备承担一定循环摩擦载荷的能力,但目前对该材料的研究主要集中在力学性能以及生物相容性方面,而对其摩擦磨损性能的研究较少,同时传统的摩擦制动材料常以磷灰石作为填料,而HA和氟磷灰石玻璃陶瓷都含有磷灰石,因此可能在摩擦制动领域具备一定的应用潜力。本文以硅酸盐相图为依据,设计氟金云母／氟磷灰石玻璃陶瓷的基体,采用熔铸法制备材料；借助x射线衍射、扫描电镜及能谱分析、热分析、透射电镜、原子力显微镜等检测手段对玻璃陶瓷的相组成和显微形貌进行分析和研究。研究了玻璃陶瓷主要晶化相及其含量与力学性能、摩擦磨损性能的关系；为了探索氟金云母／氟磷灰石玻璃陶瓷在工业摩擦领域应用的可能性,采用粉末冶金方法制备了玻璃陶瓷和HA复合材料,研究了两者的摩擦磨损性能,结果显示铜对稳定材料的摩擦状态有着重要作用,并且玻璃陶瓷基复合材料在高温下的摩擦磨损性能更好。本论文共包含图80幅、表14个、引用参考文献151篇。主要研究内容和结果如下：(1)采用熔铸法和阶梯形热处理方法制备了氟金云母／氟磷灰石玻璃陶瓷,其中氟金云母晶体呈片状和块状形貌,氟磷灰石呈针状形貌。(2)氟磷灰石的生长机理为螺型位错生长机制,氟磷灰石针状晶体的尖端为位错生长的台阶源,c晶面的生长速度较快,使得氟磷灰石具备典型的针状形貌。(3)随着氟磷灰石成分含量的增加,玻璃陶瓷的晶化度明显提高,力学性能也逐渐增加。当原料中氟磷灰石的理论含量达到40%时,玻璃陶瓷的抗弯强度、断裂韧性、显微硬度都达到最大值,分别为93.22MPa、3.74MPa·m1/2698MPa。(4)随着氟磷灰石含量的增加,玻璃陶瓷的摩擦系数升高并且波动逐渐减小。当氟磷灰石的理论含量增加到40%时,玻璃陶瓷的磨损率降至原来的1/3。(5)只含有氟金云母晶体时,材料力学性能较差,表面抗剪切能力较弱,摩擦系数较小,磨损率较大,摩擦表面的粗糙度较高。随着氟磷灰石成分含量的增加,材料的力学性能提高,表面抗剪切能力提高,摩擦系数增大,磨损率降低,摩擦表面的粗糙度降低。(6)氟磷灰石含量较低时,材料表面容易断裂剥落,磨屑中大尺寸颗粒比例较高,由于磨屑和摩擦表面的残余玻璃相含量较高,在摩擦热作用下,残余玻璃相出现软化和塑性变形,因此形成的磨屑具有一定的粘性,容易出现团聚。随着氟磷灰石含量的增加,磨屑粒度减小,团聚现象减少。(7)以HA、铜纤维、碳纤维、云母、钛酸钾为原料,采用热压工艺制备复合材料。定速摩擦实验表明,铜含量的增加时,有助于稳定材料的摩擦状态,降低磨损率。(8)以氟金云母／氟磷灰石玻璃陶瓷、铜纤维、碳纤维、钛酸钾、氮化硼、硫化锑等为原料,采用热压工艺制备玻璃陶瓷基复合材料。定速摩擦实验表明,在100-350℃度范围内,玻璃陶瓷复合材料的摩擦系数稳定在0.37左右,受温度的影响较小,耐磨性较好。(9)铜纤维的加入,提高了复合材料摩擦表面的塑性,使得摩擦过程中材料的表面形成一层摩擦膜,有助于稳定摩擦系数和降低磨损率。更多还原

【Abstract】 Glass-ceramics have excellent properties such as high mechanical strength, good wear resistance and high chemical resistance, which make it have great prospect in architecture, electronics, space and aircraft, medicine, and so on. Glass-ceramics is prepared using oxide such as SiO2, MgO, Al2O3, etc. The source of the raw materials of glass-ceramics is widely, and the energy consumption and pollution during the process of produce and using of glass-ceramics is lower, therefore glass-ceramics has obtained great research and production. Fluorphlogopite/fluorapatite has good machinable property, bioactivity and biocompatibility, has obtained great developments as dental and orthopedics material, but in these fields, the material must has better mechanical and friction and wear behaviors. But recently, the researchs are mostly focus on the mechanical property and biocompatibility, less in research on friction and wear properties. Apatite is always used as filler in industrial friction material fields, and HA and fluorapatite glass-ceramics both contains apatite, so we believe there is possible that they can be used in industrial friction material fields.The design of the glass matrix of fluorphlogopite/fluorapatite glass-ceramics is based on the silicate phase diagram, and the material was prepared by melting method, the phase compositions and microstructure of the glass-ceramics were analyzed by X-ray diffraction, scanning electronic microscopy and energy spectrum analysis, thermal analysis, transmission electron microscope, atomic force microscope. The relation between the crystalline phase and mechanical property, friction and wear property of the glass-ceramics were investigated. In order to investigate the feasibility of glass-ceramics were used in industrial fields, glass-ceramic and HA matrix composites were prepared by powder metallurgy method, the friction and wear behavior of the composites were investigated. It was found that copper is important to stabilize the friction state of the composites, and the glass-ceramic matrix composite has better friction and wear behavior under high temperature. The thesis contains80 pictures,14tables,151references. The main research contents and results are as follows.(1) The glass-ceramic was prepared by melting method and stepped heat treatment. Fluorphlogopite crystals showed a block or flake shaped morphology, fluorapatite crystals showed a needle-like morphology.(2) The growth mechanism of fluorapatite is screw dislocation growth. The conic tip of the needle is the growth source of the screw dislocation. The growth rate of the c crystal plane is faster than others, so that fluorapatite crystal shows a needle-like morphology.(3) With increasing of the raw material of fluorapatite in the glass-ceramics, the crystallinity of the glass-ceramics was increased markedly, and the mechanical property was improved. When the nominal content of fluorapatite come to40%, the mechanical behavior of the glass-ceramics, such as bending strength, fracture toughness, and micro-hardness reached to the top value, that was93.22MPa,3.74MPa-m1/2,698MPa.(4) With increasing fluorapatite, the friction coefficient of glass-ceramics increased and become stable. When the nominal content of fluorapatite increased to40%, the wear rate of the glass-ceramics was lowed to a third of the original.(5) When there was only fluorphlogopite crystal, the mechanical property is limited. The surface has poor anti-shear ability, so the friction coefficient was low and the wear rate was high, and the surface roughness is high. With increasing fluorapatite, the mechanical property is improved, and the anti-shear ability was also improved, so the friction coefficient increases and the wear rate decreased, and the surface roughness was reduced.(6) When low in fluorapatite, fracture and delamination were easy to happen on the surface, so most of the debris is big in size. The debris and surface is high in residual glass phase, under the effect of the energy accumulated during wear tests, the residual glass phase softened and showed plastic deformation, so the debris showed viscous and the agglomerate phenomena happened. With increasing fluorapatite, the size of the debris was reduced and the agglomerate phenomena were decreased.(7) HA based composite was fabricated by hot pressing with HA, copper fibers, carbon fibers, mica, and potassium titanate. The constant speed wear test showed that with increasing Cu, the friction coefficient was lowed and stabilized, and the wear rate is decreased.(8) Glass-ceramics based composite was fabricated by hot pressing with fluorphlogopite/fluorapatite glass-ceramics, copper fibers, carbon fibers, potassium fitanate, boron nitride, antimony sulfide. The constant speed wear test show that the friction coefficient tended to steady at0.37during100-350℃, and the composite showed a good wear resistance and free from interfere of temperature.(9) The adding of copper fibber could help to form a friction film on the surface of composites, which make contribution to the stable friction coefficient and the decreased wear rate.更多还原