硅灰石与纳米MoS2对丙烯酸酯橡胶摩擦磨损性能的影响

采用无转子硫化仪、环-块式摩擦试验机、电子和光学显微镜等分析表征手段,考察了硅灰石及其与纳米二硫化钼(MoS2)并用对丙烯酸酯橡胶(ACM)摩擦磨损性能的影响。结果表明,随着硅灰石用量的增加,改性ACM硫化胶的摩擦因数逐渐降低,而磨损体积呈现出先降低后升高的趋势;当硅灰石用量为35 phr时,硫化胶具有较小的摩擦因数和最好的耐磨性。在35 phr硅灰石改性ACM基础上添加1 phr纳米MoS2时,硫化胶的摩擦因数和磨损体积分别下降到0.4和1.54 mm3,表现出最低的摩擦因数和磨损体积,同时还保持较好的硫化和力学性能。纳米MoS2与硅灰石并用改性ACM时,硫化胶表现出轻微的磨粒磨损特征,磨损面平整光滑,形成的转移膜薄且完整均匀。     

硅灰石与石墨对聚四氟乙烯摩擦磨损性能的影响

以针状的硅灰石和鳞片石墨为填料,采用冷压—烧结工艺制备了不同填料含量的聚四氟乙烯（PTFE）复合材料,考察了复合材料的摩擦磨损性能,并利用扫描电子显微镜对磨痕和转移膜进行了分析。结果表明,单独填充硅灰石和石墨时,PTFE的磨损率都会随填料含量的增加而降低,硅灰石的作用要强于石墨;但硅灰石会使PTFE的摩擦因数明显增大,而石墨会使PTFE的摩擦因数降低;2种填料提升PTFE耐磨性的作用机理不同,硅灰石在摩擦过程中会在滑动界面区域上逐渐堆积,起到优先承担载荷的作用;而石墨在摩擦过程中会发生片层的滑移与剥离,有助于转移膜的形成;适量的硅灰石（含量为20 %,质量分数,下同）与石墨（含量为5 %或10 %）复合填充能产生协同效应,使PTFE的磨损率进一步降低,耐磨性比未填充的PTFE提高200倍。     

模数对无机富锌涂料和涂层性能的影响

硅酸钾富锌涂料是目前广泛使用的钢铁防腐蚀涂料。作为涂料粘结剂的高模数硅酸钾溶液对涂料和涂层的性能有重要影响。本研究考察了硅酸钾粘结剂的模数变化对涂料及涂层性能产生的影响。实验结果表明：粘结剂模数的提高可以提高固化后涂层的耐水性能，当粘结剂模数在5.0左右时，所得富锌涂层具有最佳的耐磨性能，但当粘结剂模数超过5.5时会造成涂料施工性能和贮存稳定性下降，涂层柔韧性降低，从而降低涂层的耐磨性能。     

氮化钛仿金镀层的耐磨性研究

采用多孤离子镀的方法,在1Cr13不锈钢及黄铜镀铬基体的表面上制备了氮化钛仿金装饰膜层。通过试验,得到了不同工艺参数情况下各种氮化钛膜层,采用盘销式摩擦磨损试验机测定了膜层的比磨损率。分析了膜层的耐磨性与各工艺参数间的关系,发现轰击电压的变化对膜层的耐磨性影响最大。     

Effect of Na2SiO3 concentration on corrosion resistance and wear resistance of MAO ceramic film on the Al-Mg-Sc alloy

Although Al-Mg-Sc alloy was widely applied to aviation aerospace field, they were vulnerable to local corrosion and wear in the process of long-term service in severe environmental conditions. In this paper, micro-arc oxidation (MAO) ceramic films on Al-Mg-Sc alloy substrate were prepared in electrolyte solutions with different Na₂SiO₃ concentrations, and the corrosion resistance and wear resistance of the MAO samples were studied. The experimental results of potentiodynamic polarization (PDS) and long-term immersion tests indicated that the MAO ceramic film prepared in 10 g/L Na₂SiO₃ electrolyte solution had the best corrosion resistance, as manifested by no obvious cracks, serious collapse and corrosion products on the sample surface and no deep cracks and corrosion paths in the cross-sectional area. The increase of Na₂SiO₃ concentration in electrolyte solution also improved the wear resistance of MAO ceramic film, as manifested by low wear depth (10 μm)and width (1 mm) of the MAO ceramic film prepared in 10 g/L Na₂SiO₃ electrolyte solution against GCr15 steel ball. Studies in mechanisms suggested that as the Na₂SiO₃ concentration in the electrolyte increased, the MAO ceramic film became denser, which could prevent the penetration of corrosive medium, promote the generation of the anti-wear layer with SiO₂ as the main component to enhance the wear resistance. MAO ceramic film formed in Na₂SiO₃ electrolyte solution provided good protective performance for Al-Mg-Sc alloy in the corrosion and wear conditions, which had a broader application prospect.     

Simultaneous enhancement of hardness and wear and corrosion resistance of high-entropy transition-metal nitride

Binary transition-metal nitrides (TMNs) are widely used as protective coating materials, and enhancing key performance characteristics are crucial to improving their robust and durable applications in harsh service environments. Compositional modulation via multiple elemental species offers an effective approach for optimizing physicochemical properties of TMNs, and establishing the composition–property relation is essential to the design of high-performance TMNs. In this work, we report on a comparative study of our synthesized NbN, NbMoN, and (NbMoTaW)N films and examined their microstructure, mechanical properties, and tribological and corrosion behaviors. The high-entropy (NbMoTaW)N film exhibits the highest hardness of 23.5 ± 1.35 GPa, which is ascribed to its high structural stability, increased elastic constant, and elastic modulus compared to the NbN and NbMoN films. The (NbMoTaW)N film also possesses the best wear resistance stemming from the highest H/E ratio and formation of self-lubricating MoO₃ and WO₃ species; moreover, this film shows the best corrosion resistance attributed to the sluggish diffusion of Cl⁻ due to lattice contraction and the structural stability caused by high-entropy effect. This work demonstrates simultaneously enhanced hardness and wear and corrosion resistance in a high-entropy TMN, opening a pathway for developing a new generation of advanced protective coating materials.     

Wear-corrosion behavior of ultra-thin diamond-like carbon nitride films on aluminum alloy

Diamond-like carbon films exhibit high hardness, high wear resistance and a low friction coefficient. They are extensively utilized in the mechanical, electronic and biomedical industries. This work evaluates the effect of the thickness of ultra-thin diamond-like carbon nitride films on their corrosion properties and their wear-corrosion resistance in a mixed 1 M NaCl + 1 M H₂SO₄ solution using electrochemical methods. The corrosion current density and weight loss of all films during and after wear-corrosion test are also recorded. This work employs ion beam-assisted deposition (IBAD) to deposit DLC nitride films of various thicknesses (1.5, 2.0, 2.5 and 3.0 nm), containing 60% nitrogen gas in the form of a gaseous mixture of C₂H₂ + 60%N₂. The thickness of the films was measured using a transmission electron microscope (TEM). The atomic bonding structures of these DLC nitride films are analyzed using a Raman spectrometer and by electron spectroscopy for chemical analysis (ESCA). A scanning electron microscope (SEM) was adopted to elucidate the surface morphologies of the specimens after corrosion and wear-corrosion. The results indicated that all of the nitrogen-containing DLC films excellently protected the 5088 Al–Mg alloy substrate with an electroless plated Ni–P interlayer against corrosion, and that the degree of protection increases with the thickness of the film. In the wear-corrosion tests various potentials were applied during wear in the particular corrosive solution. The results further demonstrated that the wear-corrosion resistance of all the nitrogen-containing DLC films was as effective as corrosion protection, and that the wear-corrosion loss decreased as the film thickness increased.     

氮化物陶瓷粉体的制备技术及发展趋势

氮化物陶瓷具有优异的耐高温、抗腐蚀、耐磨损性能,是一类应用广泛的结构功能材料。采用烧结方式制备结构与性能满足要求的氮化物陶瓷材料,有必要首先合成符合一定纯度和烧结活性的氮化合物粉体。本文综述了传统产业化氮化物陶瓷粉体的制备技术,以及新型合成技术的研究进展;对现有技术中存在的问题做了归纳总结,并依据国家政策层面的需求和支持提出该领域的发展趋势。     

氮化硅陶瓷的制备及性能研究进展

氮化硅陶瓷是一种具有广阔发展前景的高温、高强度结构陶瓷,它具有强度高、抗热震稳定性好、疲劳韧性高、室温抗弯强度高、耐磨、抗氧化、耐腐蚀性能好等高性能,已被广泛应用于各行业。本文介绍了氮化硅陶瓷的基本性质．综述了氮化硅陶瓷的制备工艺和提高其高温性能的方法以及增韧的途径,并展望了氮化硅陶瓷的发展前景。     

Investigating the microstructures and properties of Mg-Al LDH film-coated Mg-Li alloy: Effect of hydrothermal temperature

Magnesia-alumina layered double hydroxide (Mg-Al LDH) films grown in situ on LA43M magnesium-lithium (Mg-Li) alloy were synthesized utilizing the hydrothermal method. Scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and X-ray diffraction (XRD) were used to characterize the surface morphologies, composition, and phase of the Mg-Al films. The corrosion resistance of the Mg-Al films was estimated via immersion experiment and hydrogen evolution test, and the tribological properties were investigated using tribological wear tests. The results showed that the thickness of the Mg-Al LDH film enhanced, and the size of the LDH sheets increased as the hydrothermal temperature raised, resulting in the improvement of the corrosion and wear resistance. When the hydrothermal temperature reached 110°C, interlayer anions were loaded the most, and the film achieved the optimal thickness. The Mg-Al LDH film had the optimum corrosion resistance and tribological properties. At this point, the weight loss of the film was 1.3560 mg·cm^–2, and the average friction coefficient was .149. It demonstrated that synthesizing Mg-Al LDH at a hydrothermal temperature of 110°C was an effective approach to improve the corrosion resistance of LA43M.     

Tribomechanical and microstructural properties of cathodic arc-deposited ternary nitride coatings

Sintered carbides are promising materials for surfaces that are exposed to extreme wear. Owing to their high service load, ceramic-based thin films are coated on carbides using different techniques. In this study, non-toxic and cobalt-free powder metallurgy-sintered carbide samples were coated with TiN, TiAlN, CrAlN, and TiSiN ceramic-based thin film coatings by cathodic arc physical vapor deposition. The microstructure (phase formation, coating thickness, surface roughness, and topography), mechanical properties (hardness, modulus of elasticity, and plasticity indices), and tribological properties (nanoscratch and wear behavior) of the thin film coatings were investigated. No cracks or defects were detected in these layers. The ceramic-based ternary nitride thin film coatings exhibited better mechanical performance than the TiN coating. The TiN thin film coating had the highest average surface roughness, which deteriorated its tribological performance. The ternary nitride thin film coatings exhibited high toughness, while the TiN thin film coating exhibited brittle behavior under applied loads when subjected to nanoscratch tests. The wear resistance of the ternary nitride coatings increased by nearly 9–17 times as compared to that of the TiN coating and substrate. Among all the samples investigated, the substrate showed the highest coefficient of friction (COF), while the TiSiN coating exhibited the lowest COF. The TiSiN thin film coating showed improved mechanical and tribological properties as compared to other binary and ternary nitride thin film coatings.     

A comparative study on the synthesis and properties of suspension and solution precursor plasma sprayed hydroxyapatite coatings

In the present study, hydroxyapatite (HAp) coatings were deposited on Ti-6Al-4V alloy by solution precursor plasma spray (SPPS) and suspension plasma spray (SPS) processes and the properties of the coatings were compared. The feedstock powder for SPS method was prepared by coprecipitation technique and characterized for phase and morphology. The obtained HAp coatings were characterized by X-ray diffractometry, Raman spectroscopy and FT-IR spectroscopy. The biocompatibility of the coatings was evaluated using osteoblast like cells. Both the SPS and SPPS hydroxyapatite coatings exhibited similar crystallinity. Interestingly, the HAp-SPS coating showed marginally higher biocompatibility compared to HAp-SPPS and control samples. The wear and corrosion behavior of these coatings was also studied in Hanks' medium. The hydroxyapatite coating fabricated from SPS technique exhibited better corrosion and wear resistance compared to SPPS coating.     

Wollastonite/hydroxyapatite scaffolds with improved mechanical,bioactive and biodegradable properties for bone tissue engineering

Wollastonite/hydroxyapatite composite scaffolds are proposed as bone graft. An investigation on scaffold with varying reinforcing wollastonite content fabricated by polymeric sponge replica is reported. The composition, sintering behavior, morphology, porosity and mechanical strength were characterized. All the scaffolds had a highly porous well-interconnected structure. A significant increase in mechanical strength is achieved by adding a 50% wollastonite phase. The most mechanically resistant (50/50) wollastonite/hydroxyapatite scaffolds were soaked in both simulated body fluid (SBF) and Tris–HCl solution in order to assess bioactivity and biodegradability. A carbo-hydroxyapatite layer formed on their surfaces when immersed in SBF. The biodegradability tests reveals that the composite scaffold shows a higher degradation rate compared to pure hydroxyapatite used as comparison. These results demonstrate that the incorporation of a 50% of wollastonite phase in hydroxyapatite matrix is effective in improving the strength and the bioactive and biodegradable properties of the porous scaffolds.     

Pulsed laser deposition of hydroxyapatite-diamondlike carbon multilayer films and their adhesion aspects

We have developed a layered hydroxyapatite/diamondlike carbon/functionally gradient diamondlike carbon-silver/titanium carbide/titanium carbonitride/titanium nitride composite film using pulsed laser deposition. A diamondlike carbon interlayer between a hydroxyapatite coating and the Ti-6Al-4V alloy can serve several purposes, including preventing corrosion of Ti-6Al-4V alloy, overcoming poor adhesion between the hydroxyapatite coating and the titanium oxide surface, and reducing inflammation at the implant/tissue interface. Titanium nitride, titanium carbonitride (TiC _x N _y ), titanium carbide and functionally gradient diamondlike carbon-silver layers were used to improve the adhesion of diamondlike carbon films to Ti-6Al-4V alloy. We envision several potential medical applications for these multilayer materials, including use in orthopedic and dental devices.     

The tribological performance of BCN films under ionic liquids lubrication

Boron carbon nitride films were deposited onto silicon substrates by medium frequency magnetron sputtering from graphite and boron targets with Ar and N₂ as feedstock. The three elements of B, C and N were bonded to each other and an atomic-level hybridized B–C–N had been formed in the films. The tribological performances of the boron carbon nitride film with 1-butyl, 3-methylimidazolium tetrafluoroborate ionic liquid as lubricant and the electrochemical corrosive behaviors of the BCN film were investigated. The boron carbon nitride film demonstrated excellent tribological properties and corrosion resistance as compared with diamond like carbon film. An extensive discussion of the effect of film intrinsically structure on both lubrication and corrosion under ionic liquid condition is given. In addition, the interrelation between the tribological properties and corrosion resistance is illustrated.     

Corrosion,wear and wear–corrosion behavior of graphite-like a-C:H films deposited on bare and nitrided titanium alloy

This work presents a comparative wear, corrosion and wear–corrosion (the last one in a simulated physiological solution) study of graphite-like a-C:H (GLCH) films deposited on bare and nitrided Ti6Al4V alloy. Films, deposited by r.f. PACVD, presented low porosity and promoted high corrosion resistance. The friction coefficient of the films was very low with appreciable wear resistance at room conditions. However, due to the simultaneous action of both load and the corrosive environment in wear–corrosion tests a marked reduction in the coating lifetime was observed. Unexpectedly, films deposited on the nitrided alloy presented a lifetime at least ten times shorter than that of films on bare alloy. We explain such a result in terms of film/substrate interaction. The weak GLCH/nitrided alloy interaction facilitates fluid penetration between the film and the substrate which leads to a fast film delamination. Such an interpretation is supported by force curve measurements, which show that the interaction between GLCH and nitrided alloy is four times weaker than that between GLCH and bare alloy.     

Mechanical,tribological and electrochemical behavior of Zr-based ceramic thin films for dental implants

To determine the possibility of using new thin films architectures as biocompatible materials, an experimental and computational study was performed to evaluate the mechanical, tribological, and corrosion properties in simulated physiological media (saliva and blood plasma) of Zr, ZrN, and ZrN/Zr coatings, deposited by PVD magnetron sputtering. The crystalline structure and chemical composition were well correlated with high resistance to plastic deformation, wear, and corrosion, making these materials excellent candidates for functionalizing and protecting dental prostheses. The predominant wear mechanism under consideration was abrasion, which was reduced when using ceramic ZrN coating as a base for the superficial Zr thin film. When exposed to simulated body fluids, these materials exhibited high corrosion resistance, which was demonstrated by potentiodynamic measurements. These results are consistent with those predicted by Density Functional Theory computational models, which showed that electron transfer associated with the wear mechanism is kinetically impeded, as a consequence of the large energy barriers for this process associated with the adsorption of the molecular species on the ZrN surface. Additionally, calculated adsorption energies indicated that urea (from the simulated saliva solution) interacts strongly with the surface. This interaction was associated to the formation of passivating protective layers, which is a key mechanism to protect against corrosion, acting in synergy with the kinetic barriers.     

类金刚石薄膜在人工关节摩擦副表面改性进展

类金刚石（DLC）薄膜由于其优异的减摩耐磨性以及良好的生物相容性被引入到人工关节材质中。该文综述了DLC薄膜在人工关节摩擦副表面改性的研究现状，包括DLC薄膜的分类和制备方法。尽管该薄膜已被研究数十年，但在人体复杂的生理力学环境中高负荷摩擦腐蚀等综合作用下，仍存在高内应力导致结合力不足，从而限制其在人工关节领域的应用。该文介绍了降低DLC薄膜内应力提高膜基结合力的方法和DLC薄膜生物相容性的研究进展。最后，对不同DLC薄膜人工关节摩擦副的研究进展进行了阐述。根据该综述，提出厚的无氢DLC涂层（高sp3含量），且在两个滑动表面上均有DLC薄膜的人工关节副具有优异的耐磨性，对于承重植入体应用至关重要。     

弹簧件常温复合发蓝工艺研究

传统的常温发蓝工艺存在着附着力和耐磨性差的缺点，研究了一种用于弹簧件的常温复合发蓝工艺，介绍了前处理，发蓝及后处理工序，测量了发蓝膜的附着力，耐磨和耐蚀性，并与传统常温发蓝进行了对比。复合发蓝膜的附着力，耐磨和耐蚀性明显优于传统常温发蓝膜。这是由于复合发蓝膜的孔隙中生成的磷化膜的作用导致的。     

Multifunctional hybrid coating on titanium towards hydroxyapatite growth: Electrodeposition of tantalum and its molecular functionalization with organophosphonic acids films

Titanium and its alloys are base materials used in the dental and orthopaedic fields owing to suitable intrinsic properties: good biocompatibility, high corrosion resistance and excellent mechanical properties. However, the bonding between titanium and bone tissue is not always strong enough and can become a critical problem. In this context, the two main objectives of this paper are the increase of the corrosion resistance and the improvement of the hydroxyapatite (HAp) growth. The surface modification considered here is achieved in three main steps and consists in the elaboration of different inorganic and organic coatings. The first step is the elaboration of electrodeposition of tantalum on the titanium oxide film of a titanium substrate. The second step is the modification of the tantalum oxide coating with organophosphonic acids. The last step is the nucleation and growth of HAP on the outermost layer of the system by immersion in a simulated body fluid. The hybrid coating tantalum oxide/organophosphonic acids/molecular layer is shown to be promising for orthopaedic implants.