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The purpose of this study is to improve the mechanical and tribological performance of polypropylene (PP) material. The influence of hexagonal boron nitride (h-BN) microparticles on mechanical and tribological properties of PP/polyamide 6 (nylon 6) (PA6) blend has been investigated in this paper.

Tensile strength, elongation, elastic modulus and Rockwell hardness were measured to identify the mechanical properties of materials. Coefficient of friction (COF) and wear rates of materials were measured with the help of a pin-on-disc tribometer to check the tribological behavior of blend and composite materials.

As a result, a small decrease in tensile strength and elongation and improvement in elastic modulus were found for PP/PA6 and PP/PA6/h-BN composite compared to pure PP. The wear rate of PP/PA6 blend and PP/PA6/h-BN composite was found low compared to pure PP matrix, while the COF of PP/PA6 blend was found slightly higher owing to the presence of harder PA6 matrix which was then improved by the h-BN filler reinforcement in PP/PA6/h-BN composite. The addition of PA6 in PP improved the wear rate of PP by 8–24%, whereas the addition of h-BN microparticles improved the wear rate by 22–50% and 24–44% compared to pure PP and PP/PA6 blend, respectively, in different parameters.

Modulus of elasticity and hardness of pure PP was enhanced by blending with PA6 and was further improved by h-BN fillers. The addition of PA6 in PP improved the wear rate, while h-BN fillers were found effective in reducing the COF by generating smooth thin lubricating film.

The purpose of this paper is to investigate the effect of doping element on the structural, thermal properties, mechanical performance and the failure mechanism of hexagonal nano boron nitride (h-BN)-reinforced basalt fabric (BF)/epoxy composites produced by hand lay-up and vacuum bagging technique. h-BN particles doped to composite materials increased the tensile, bending and impact strength of the composite at certain rates while 1 Wt. % h- BN addition shows the highest tensile and flexural strength.

The epoxy resin was doped with h-BN nanopowder at the certain rates (0, 1, 2 and 4 Wt.%) and the epoxy: hardener ratios used in the study were selected as 80%: 20% by weight. Then, with the aid of a roller by hand lay-up method, a mixture of epoxy + hardeners containing nanoparticles and nanoparticle-free were fed onto BFs, 12 layers of each dimension 30 cm × 30 cm. The surplus epoxy resin was moved away from the composite sheets using the vacuum bagging process and left to cure at room temperature for 24 h. ASTM D3039 for tensile, D7264 for three-point bending and D256 for Izod impact test were performed for the mechanical tests. After the tensile test, the morphologies of the fracture surface were examined with a stereomicroscope and various failure mechanisms are highlighted.

In this study, a series of basalt/epoxy composites with h-BN nanopowders have been prepared to identify the effect of filler ratio on mechanical properties. It has been known from the results of mechanical experiments that the addition of h-BN improves the mechanical performance of materials at a certain rate. The tensile and flexural strengths of h-BN doped composites, increase for concentrations of 1 Wt.% h-BN, but decrease with the increasing content of it. The basalt/epoxy resin composite with higher mechanical properties could be a potential material in the automotive and aerospace industries.

The aim of this study is to contribute to literature within the context of this new combination of composites and their mechanical properties, failure mechanisms. It presents detailed characterization of each composite by using X-ray differaction (XRD), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy.

The purpose of this paper is to investigate applicability of hexagonal boron nitride (h-BN) powder as a solid lubricant additive in coconut oil and to determine the tribological behavior of PEEK rubbed with DIN2080 tool steel, under prepared green lubricating condition.

In this study, tiribological performance of PEEK against the DIN2080 tool steel is investigated with green lubricant. Coconut oil was used as green lubricant and 4 per cent wt. h-BN powder was added as lubricant additive into the coconut oil. Reciprocal pin-plate tribological test were applied under dry, coconut oil and coconut oil+h-BN lubrication condition. Friction coefficients were recorded and wear behavior of the samples investigated by mass loss measurement and topographical inspection of wear track by optical profilometer.

Using coconut oil as lubricant provided 80 per cent reduction of friction coefficient and 33.4 per cent reduction of wear rate. Addition of h-BN into the coconut oil provide 84 per cent reduction of friction coefficient and 56 per cent reduction of wear rate. The results showed that vegetable oil is promising lubricant for sustainable manufacturing. h-BN serves to increase lubricant performance and decrease wear of the surfaces.

Petrochemical lubricants are one of the major sources of environmental pollution and health hazards. Development and use of environmental and health friendly lubricants support sustainability and reduce wear, friction and energy consumption. With this consciousness, recent studies have focused on green tribology and green lubricants such as vegetable oils, ionic liquid bio-lubricants and bio-based polymers.

In literature study coconut oil was proposed as green lubricant while h-BN powder was proposed as solid lubricant. However, applicability of h-BN powder in coconut oil has not been explored yet. Moreover, wear and friction property of PEEK material with DIN 2080 tool steel pair surface has not been studied yet with green lubricants.

The purpose of this paper is to investigate the corrosion behaviour of ferroboron (FeB) and FeB/h‐BN (hexagonal boron nitride) coatings deposited onto A383 substrates by atmospheric plasma spraying.

Potentiodynamic scanning (PDS) and electrochemical impedance spectroscopy (EIS) were used to evaluate the corrosion susceptibilities of the composite coatings. Microstructural characterizations were carried out by using scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS).

It was observed that the coatings resisted localized corrosion in NaCl solutions and protective oxide films on the coatings repaired themselves over the corrosion potential. Hexagonal‐BN is not only a limiting factor in the corrosion of the FeB based coatings. The corrosion morphologies of the coatings are strictly dependent on pores and micro‐cracks in the coating.

The iron‐based borides act as solid lubricants and have a positive influence on tribological properties such as hardness, friction and corrosion of the coating.

Knowledge of the effects of FeB on the corrosion behaviour of thermal spray coatings is still incomplete and this is the most important obstacle to the widespread use of the coatings in engineering applications. The paper reports electrochemical test results of the coatings and discusses the morphologic effects of h‐BN on the corrosion behaviour.

The purpose of this paper is to study the sliding and the vibrating fretting tests mechanism of h‐BN micro‐particles when used as a lubricating grease‐2 additive.

The fretting tests were conducted on steel/steel contacts using both vibrating fretting apparatus and the shaft‐sleeve slide fitted tester. The wear scars were characterized with profilometry. The tribological properties of grease‐2 compounded with h‐BN additive were also compared to those obtained for the commercial product Militec‐4.

The experiment showed significant differences between the results obtained from the vibrating fretting and the shaft‐sleeve sliding fitted tests. Adding h‐BN to the lubricant leads to a better performance in the shaft‐sleeve slide regime than in the steel/steel vibrating test condition.

The results of the experimental studies demonstrate the potential of h‐BN as an additive for preventing fretting sliding, and can very useful for further application of compound grease‐2 with h‐BN additive in industrial equipment.

The purpose of this paper is to implement a micromechanical hybrid finite element approach in order to investigate the stress transfer behavior of composites reinforced with hexagonal boron nitride (h-BN) nanosheets.

For the analysis of the problem, a three-dimensional representative volume element, consisting of three phases, has been used. The reinforcement is modeled discretely using spring elements of specific stiffness while the matrix material is modeled as a continuum medium using solid finite elements. The third phase, the intermediate one, known as the interface, has been simulated by appropriate stiffness variations which define a heterogeneous region affecting the stress transfer characteristics of the nanocomposite.

The results show a good agreement with corresponding ones from the literature and also the effect of a number of factors is indicated in stress transfer efficiency.

This is the first time that such a modeling is employed in the stress transfer examination of h-BN nanocomposites.

The absorption of moisture/water can affect the mechanical and thermal properties of polymers and polymer composites as many polymers, mainly polyamide thermoplastics, are sensitive to environmental humidity and can absorb a large amount of moisture. This paper investigates the effect of water molecules' absorption on mechanical and thermal properties of polyamide6/hexagonal boron nitride (PA6/h-BN) composites.

The PA6/h-BN composites were exposed to an open environment and water for 15 days to analyse the effect of humidity/water molecules' absorption on mechanical and thermal properties. The tensile strength, hardness and impact strength of materials were measured and compared. The scanning electron microscopy (SEM), x-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses were utilized to see the influence of water absorption on microstructure, crystallinity and glass transition temperatures.

After exposing materials to an open environment and water, the tensile strength and hardness were found to decline, while improvement in impact strength was noticed. SEM characterization revealed the formation of voids/pockets in water-immersed materials. DSC analysis revealed the loss in glass transition temperatures, and XRD analysis revealed the loss in crystallinity of water-immersed materials.

Environmental conditions vary according to the geographical areas, and it varies in many countries throughout the year. Polyamides are sensitive to the environmental humidity and can absorb a large amount of moisture from the environment. It becomes necessary to test these materials in their original working conditions, and sometimes it is mandatory to see the effects of extreme environmental conditions on a component. In this article, efforts have been made to investigate the influence of extreme humidity/water conditions on thermo-mechanical properties of PA6/h-BN composites.

The purpose of this paper is to investigate the effect of hexagonal boron nitride (h-BN) and poly (phenyl p-hydroxybenzoate) (PHBA) on improving the torsional tribological behavior of polytetrafluoroethylene (PTFE).

This paper investigates the torsional tribological behavior of PTFE composites filled with h-BN and PHBA under different angular displacements with a plane-on-plane torsional friction tester. The worn surface of PTFE composites was investigated by using a scanning electron microscope.

The shape of T–Θ curves of PTFE composites was influenced by both content fillers and torsional angule. The material with a higher coefficient of sliding friction exhibited the larger torsional angle under which the torsional regime transited from a partial slip to a gross slip. PTFE composites filled with 20 weight per cent PHBA and 10 weight per cent h-BN showed the best anti-wear properties. The specific wear rate of composites exhibits a negative correlation with material hardness. The wear volume loss presents a positive correlation with friction dissipation energy. The specific wear rate of all composites decreased with increasing torsional angle. The dominant wear mechanism of pure PTFE was adhesive wear. The slight plastic flow and plowing occurred on the worn surfaces of PTFE composites because of the higher hardness of composites and the lubrication of h-BN particles with layer crystal structure.

This paper put forward a kind of PTFE composite with low torsional wear rate, which can be used in the sliding slewing bearing or the center plate of a bogie.

The purpose of this study is to experimentally and numerically scrutinize the heat transfer enhancement in pool boiling and condensation by changing the hydrophilicity or hydrophobicity properties of the working fluid, i.e. by use of nanofluid solution.

For specifying the effects of nanoparticle concentration on heat transfer properties, two different nanofluid solutions (h-BN/DCM and SiO₂/DCM) at three different volumetric concentrations were prepared and tested under different heat flux conditions. Boiling curves, alterations in pressure with heat flux and heat transfer coefficients for both boiling and condensation processes were obtained and viscosity measurements were performed for dichloromethane (DCM) and each working fluid was prepared. In addition, a series of numerical simulations, via computational fluid dynamics approach, was performed for specifying the evaporation–condensation phenomena and temperature and velocity distributions.

Nanoparticle addition inside the base fluid increased the thermal characteristics of the base fluid significantly. For the experimental results of h-BN/DCM nanofluid, the increment rate in heat transfer coefficient for saturation boiling, after-saturation boiling and condensation processes was found as 27.59%, 14.44% and 15%, respectively.

The novelty of this comparison study is that there is no such experimental and numerical comparison study in literature for DCM fluid, which concentrates on thermal performance enhancement and compares the effect of different kinds of nanoparticles on heat transfer characteristics for boiling–condensation processes.

The purpose of this paper is to develop an effective approach to significantly improve the thermomechanical properties of shape memory polymer (SMP) nanocomposites that show fast thermally responsive shape recovery.

Hexagonal boron nitrides (h-BNs) were incorporated into polymer matrix in an attempt to improve the thermal conductivity and thermally responsive shape recovery behaviour of SMP, respectively. Thermally actuated shape recovery behaviour was recorded and monitored instrumentally.

The results show that both glass transition temperature (T_g) and thermomechanical properties of the SMP nanocomposites have been progressively improved with increasing concentration of h-BNs. Analytical results also suggest that the fast-responsive recovery behaviour of the SMP nanocomposite incorporated with h-BNs was due to the increased thermal conductivity.

A simple way for fabricating SMP nanocomposites with enhanced thermally responsive shape recovery based on the incorporation of h-BNs was developed.

The outcome of this study may help fabrication of SMP nanocomposites with fast responsive recovery behaviour.