The present research focuses on the tribological behavior of the AA5083 alloy-based hybrid surface composite using aluminosilicate and multi-walled-carbon nanotube through friction stir processing for automotive applications. The friction stir processing parameters (tool rotation and traverse speed) are varied based on full factorial design to understand their influence on the tribological characteristics of the developed hybrid composite. The surface morphology and composition of the worn hybrid composite are examined using a field-emission scanning electron microscope and an energy-dispersive x-ray spectroscope. No synergistic interaction is observed between the wear rate and friction coefficient of the hybrid composite plate. Also, adhesive wear is the major wear mechanism in both base material and hybrid composite. The influence of friction stir process parameters on wear rate and the friction coefficient is analyzed using the hybrid polynomial and multi-quadratic radial basis function. The models are utilized to optimize the friction stir processing parameters for reducing the rate of wear and friction coefficient using multi-quadratic RBF algorithm optimization.
The flaw of low dispersibility in the metal matrix brought on by graphene's full crystal structure can be improved by the application of ion beam radiation to the surface of the material. Copper atoms are uniformly dispersed on the modified graphene oxide ( GOM) surface after being irradiated to a copper ion beam, and during the sputtering modification, the valence state of copper is changed, resulting in the formation of a new CuO phase on the graphene oxide (GO) surface. Therefore, after copper ion beam irradiation of graphene, the interfacial adhesion between GOM and copper matrix is enhanced, and the wear resistance is significantly improved. When the GOM content is low, it can withstand most of the load during the friction and wear test, which reduces the wear of the copper matrix and the occurrence of fatigue cracks at the interface of the composite material.
With the increasing attention to environmental pollution caused by particulate matter globally, the automotive industry has also become increasingly interested in particulate matter, especially particulate matter generated by automobile brake systems. Here, we designed a coating composition and analyzed its mechanical properties to reduce particulate matter generated by brake systems during braking of vehicles. We designed a composition to check the mechanical properties change by adding Cr3C2 and YSZ to the WC-Ni-Cr composite composition. Based on the designed composition, coating samples were manufactured, and the coating properties were analyzed by Vickers hardness and ball-on-disk tests. As a result of the experiments, we found that the hardness and friction coefficient of the coating increased as the amount of Cr3C2 added decreased. Furthermore, we found that the hardness of the coating layer decreased when YSZ was added at 20vol%, but the friction coefficient was higher than the composition with Cr3C2 addition.
The tribological properties of TiC, TiN and TiC/TiN coatings on steels prepared by the cathodic-arc (CA) ion plating technique were investigated. Experiments were carried out on a tribo-test machine using a Falex journal V block system. The friction and wear characteristics of the coatings were determined by varying the applied load and sliding speed. The TiC, TiN and TiC/TiN coatings markedly increased the tribological characteristics of the surface. As far as a single layer coating was concerned, TiN goes better results than TiC. However, the TiC/TiN multilayer coating performed better than either single layer coating. The major factor in the improved performance of the multilayer coating was the role of TiC in improving the adhesion between the external TiN layer and the substrate steel.
The sensory stimulation of a cosmetic product has been deemed to be an ancillary aspect until a decade ago. That point of view has drastically changed on different levels in just a decade. Nowadays cosmetic formulators should unavoidably meet the needs of consumers who want sensory satisfaction, although they do not have much time for new product development. The selection of new products from candidate products largely depend on the panel of human sensory experts. As new product development cycle time decreases, the formulators wanted to find systematic tools that are required to filter candidate products into a short list. Traditional statistical analysis on most physical property tests for the products including tribology tests and rheology tests, do not give any sound foundation for filtering candidate products. In this paper, we suggest a deep learning-based analysis method to identify hand cream products by raw electric signals from tribological sliding test. We compare the result of the deep learning-based method using raw data as input with the results of several machine learning-based analysis methods using manually extracted features as input. Among them, ResNet that is a deep learning model proved to be the best method to identify hand cream used in the test. According to our search in the scientific reported papers, this is the first attempt for predicting test cosmetic product with only raw time-series friction data without any manual feature extraction. Automatic product identification capability without manually extracted features can be used to narrow down the list of the newly developed candidate products.
Composite materials offer distinct and unique properties that are not naturally inherited in the individual materials that make them. One of the most attractive composites to manufacture is the aluminum alloy matrix composite, because it usually combines easiness of availability, light weight, strength, and other favorable properties. In the current work, Powder Metallurgy Method (PMM) is used to prepare Al2024 matrix composites reinforced with different mixing ratios of yttrium oxide (Y2O3) particles. The tests performed on the composites include physical, mechanical, and tribological, as well as microstructure analysis via optical microscope. The results show that the experimental density slightly decreases while the porosity increases when the reinforcement ratio increases within the selected range of 0 ~ 20 wt%. Besides this, the yield strength, tensile strength, and Vickers hardness increase up to a 10 wt% Y2O3 ratio, after which they decline. Moreover, the wear results show that the composite follows the same paradigm for strength and hardness. It is concluded that this composite is ideal for application when higher strength is required from aluminum composites, as well as lighter weight up to certain values of Y2O3 ratio.
The life span of many engineering components depends upon their surface properties. The improved surface properties of the materials are essential for enhancing the mechanical and tribological performance of the material. In many applications, the components required only improved surface properties without changing the entire volume properties of the material. The friction stir process (FSP) is a novel processing technique for the fabrication of such surface composites. In the present investigation, the surface composites were fabricated by incorporating molybdenum disulfide ( MoS2) and graphite (Gr) as reinforcement on the surface of aluminum alloy (Al 1120) through the friction stir process (FSP) at tool rotational speed of 1400 rpm and tool feed rate of 40 mm/min process parameters using square profile FSP tool. The tribological behaviors of fabricated surface composites were calculated by using a pin on disk tribometer. It was observed that the wear resistance of surface composites improved as compared to the matrix material.
In the power steering systems used for automobiles, because of its small size and low noise, a balanced type hydraulic vane pump is mainly used as a power source. Therefore it is requested to research on the lubrication characteristics of a oil hydraulic vane pump which is the key part to improve its performance. The performance of a oil hydraulic vane pump is influenced by the lubrication characteristics of the critical sliding components. Thus, lubrication characteristics between the shaft and the journal bearing have to be researched for the design and the performance improvement of a oil hydraulic vane pump. Therefore, in this paper, it is theoretically investigated that the lubrication characteristics between the shaft and the journal bearing of a balanced type oil hydraulic vane pump for power steering systems. The results demonstrate that lubrication characteristics are significantly influenced by the clearance between the shaft and the journal bearing.
An electroless deposition method was used to modify the surface properties of rice husk ceramic particles (RHC) by depositing nano-nickel on the surface of the RHC (Ni-RHC). The dry tribological performances of aluminum matrix composite adobes containing different contents of RHC and Ni-RHC particles have been investigated using a micro-tribometer. Results showed that the Ni–RHC particles substantially improved both the friction and wear properties of the Ni-RHC/aluminum matrix adobes. The optimal concentration was determined to be 15 wt% for both the RHC and Ni–RHC particles. The improvements in the tribological properties of aluminum adobes including the Ni-RHC were ascribed to frictioninduced peeling off of Ni coating and formation of protection layer on the wear zone, both of which led to low friction and wear volume.
This study elucidates the effect of wear resistance in Forging S45C. Three wear factor which are wear loss, coefficient of friction and friction force could conduct an experiment of wear-resistance test. First of all, wear test of ball-on-disk has been performed using steel balls to determine the variation of wear characteristics. Finally, the coefficient of wear was calculated by the Archard wear equation in hot forging S45C.
The aim of experimental evaluation is to investigate the effect of wear resistance on 3D printing FDM(Fused Deposition Modeling). For this purpose, ABS(Acrylonitrile Buadiene Styrene) material was applied to test of wear-resistance. Ball-on-disk wear test has been performed using steel balls to determine the variation of tribological characteristics. Friction coefficient, wear loss and friction force showed a difference in the respective test conditions.
In order to determine the wear properties of CVD ceramic coatings, wear process was evaluated using the coated pin of Falex Tribosystem. Also, in order to determine the effects of coating material on wear process, TiC,N of thickness 5m∼6m coated by Thermal CVD method were applied. The wear property of TiC,N film, the higher the deposition temperature was, the closer the lattice parameter was to the amount of the standard power, and the grain size increased. According to the wear formation, under the control that there is on specific wear rate wear parameter and coating delamination, decrease with increasing sliding friction and when the coating delamination happened.
We investigated tribological characteristics of diamond-like carbon (DLC) in a condition with carbon nanotube (CNT) content of 1wt% in aqueous solution. Si-DLC films were deposited by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) process on Al6061 aluminum alloy. In this study, the deposition of DLC films was carried out in vacuum with a chamber pressure of 10-5 to 10-3 Torr achieved by mechanical pump followed by turbo molecular pump. The surface adsorbed oxygen on the Aluminum substrates was removed by passing Ar gas for 10 minutes. The RF power was maintained at 500W throughout the experiment. A buffer layer of HMDSO was deposited on the substrate to improve the adhesion of DLC coating. At this point CH4 gas was introduced in the chamber using gas flow controller and DLC coating was deposited on the buffer layer along with HMDSO for 50 min. The thickness of 1 μm was obtained for DLC films on aluminum substrates The tribological properties of as synthesized DLC films were analyzed by wear test in the presence of dry air, water and lubricant such as CNT ink.
Transparent ceramics are used in new technology because of their excellent mechanical properties over glasses. Transparent ceramics are nowadays widely used in armor, laser windows, and in high temperature applications. Silicon nitride ceramics have excellent mechanical properties and if transparent silicon nitride is fabricated, it can be widely used. h-BN has a lubricating property and is ductile. Therefore, adding h-BN to silicon nitride ceramics gives a lubricating property and is also machinable. Translucent silicon nitride was fabricated by hot-press sintering (HPS) and 57% transmittance was observed in the near infrared region. A higher wt. % of h-BN in silicon nitride ceramics does not favor transparency. The optical, mechanical, and tribological properties of BN dispersed polycrystalline Si3N4 ceramics were affected by the density, α:β-phase ratio, and content of h-BN in sintered ceramics. The hot pressed samples were prepared from the mixture of α-Si3N4, AlN, MgO, and h-BN at 1850˚C. The composite contained from 0.25 to 2 wt. % BN powder with sintering aids (9% AlN + 3% MgO). A maximum transmittance of 57% was achieved for the 0.25 wt. % BN doped Si3N4 ceramics. Fracture toughness increased and wear volume and the friction coefficient decreased with an increase in BN content. The properties such as transmittance, density, hardness, and flexural strength decreased with an increase in content of h-BN in silicon nitride ceramics.
Oil-based nanofluids were prepared by dispersing Ag, graphite and carbon black nanoparticles in lubricating oil. Agglomerated nanoparticles were dispersed evenly with a high-speed bead mill and/or ultrasonic homogenizer, and the surfaces of the nanoparticles were modified simultaneously with several dispersants. Their tribological behaviors were evaluated with a pin-on-disk, disk-on-disk and four-ball EP and wear tester. It is obvious that the optimal combination of nanoparticles, surfactants and surface modification process is very important for the dispersity of nanofluids, and it eventually affects the tribological properties as a controlling factor. Results indicate that a relatively larger size and higher concentration of nanoparticles lead to better load-carrying capacity. In contrast, the use of a smaller size and lower concentration of particles is recommended for reducing the friction coefficient of lubricating oil. Moreover, nanofluids with mixed nanoparticles of Ag and graphite are more suitable for the improvement of load-carrying capacity and antiwear properties.
The tribological properties of acrylonitrile-butadiene rubber (NBR) filled with two kinds of carbon black filler were examined. Different types of Semi-Reinforcing Furnace (SRF), and High Abrasion Furnace (HAF) blacks were used as filler material to test the influence of carbon black particle size on the friction and wear of NBR. Results from tribological tests using a ball on disk method showed that the smaller HAF particles were more effective for reducing the wear of NBR during frictional sliding. The hardness, elastic modulus at 100% elongation, and elongation at break were measured to examine the correlation between the effects of carbon black on the mechanical and tribological properties of the NBR specimens. The wear tracks of the NBR specimens were observed with scanning electron microscopy (SEM). The wear tracks for NBR with different ratios of SRF and HAF showed clearly different abrasion patterns. Mechanisms for the friction and wear behavior of NBR with different sizes of carbon black filler were proposed using evidence from wear track observation, as well as the mechanical and tribological test results.
Dry sliding wear behavior of electro-pressure sintered Co-Fe, Co-Ni and Co-Fe-Ni compacts was investigated. Pin-on-disk wear tests were performed on the sintered compacts disk specimens against alumina and silica ball counterparts at various loads ranging from 3N to 12N. Two sliding speeds of 0.1m/sec and 0.2m/sec and a fixed sliding distance of 1,000m were employed. Worn surfaces and cross sections of them were examined by a scanning electron microscopy, and wear mechanism of the compacts was investigated. Effects of the oxide layer that was formed on wearing surface of the compacts on the wear were also studied.