Papers by Keyword: Wear Characteristics

Abstract: Upgrading of reinforcements with suitable combinations in Aluminum-based hybrid metal matrix composites became a key area of research in the current manufacturing era. These advanced materials have enriched Properties like specific strength, wear resistance, and low thermal expansion. With these perceptions, the current research paper was focused on AA-2024/MoS2/Al2O3 HMMCs. Taguchi L18 orthogonal array was adopted to design the experiments. Hybrid composites containing MoS2 and Al2O3 reinforcements were fabricated by the stir casting method. The pin on disk tribometer was used for finding the wear rate and coefficient of friction of prepared composites by considering sliding speed, applied load, and sliding time as wear parameters. Further, the influence of wear parameters on Wear Rate and Coefficient of Friction (COF) was presented. Consequently, the significance of the parameters on wear rate and COF are analyzed by analysis of variance (ANOVA).

Abstract: Due to wear failures caused by tubing string vibrations in high-pressure, high-temperature and high-yield (3H) gas wells, a wear experiment was performed on the 13Cr-L80 tubing string. The influence of contact load, friction frequency, and reciprocating stroke length on the wear characteristics of the tubing string were effectively analyzed using the control variable method. The results demonstrate that, the wear patterns of the tubing-casing were primarily abrasive and adhesive wears, with minimal corrosion wear. The wear amount of tubing increases linearly with the increase of contact load and reciprocating stroke, but increases nonlinearly with the increase of friction frequency, and the friction coefficient of tubing string do not change with the increase of contact load, friction frequency and reciprocating stroke. In-field operations, the service life of the tubing string in 3H gas wells can be effectively augmented by reducing the contact load and longitudinal vibration displacement of the tubing-casing, maintaining the vibration frequency of the tubing string below 1.5 Hz. These results provide useful guidance for designing and implementing approaches to improve the service life of tubing strings in high-yield gas wells.

Abstract: The Aeolian vibration wear test of the self-damping conductors for large crossing was carried on a fretting fatigue wear test-bed. This test has been finished in three different vibration times under 25% ultimate tensile strength (UTS). The morphology observations and dimension measurement of aluminum wire wear scar has been analyzed by means of scanning electron microscope (SEM) and DMR multifunctional microscope. By observing the surface morphology and composition of the conductors, the influence law on the wire wear has been analyzed, and the analysis results reveal the contact wear mechanism, which is basically in accord with the working wires. The result shows the worn spots of the transmission line is an elliptic shape. The test result has important guiding meaning in further study on wear characteristics of self-damping conductors for large crossing under aeolian vibration.

Abstract: A wire tool having electrodeposited diamond grains is frequently used for machining hard and brittle materials such as silicon ingots, magnetic materials, ceramics, and sapphires. This study aims to examine the wear characteristics of the tool during the microgrooving of ceramics. We conducted microgrooving experiments for alumina ceramics. The results indicate that the grooving time and the machining distance influence the groove depth. However, as the damage in a wire tool progresses, the groove depth does not depend on the machining distance. A fast relative velocity leads to serious damage in the wire tool even when the machining time is short. In the case of wet grooving, the damage to the wire tool was smaller than that in the case of dry grooving.

Abstract: This study investigated the wear characteristics and anti-loosening characteristics of flank lock type precision locknut in the dynamic percussion vibration test. The experiment was conducted by using horizontal realistic dynamic percussion vibration test machine. The objective is to simulate the loosening condition of the locknut which was assembled in ball screw and machine tool spindle. Through this study, the wear resistance and anti-loosening characteristics of the precision locknut under the dynamic test were investigated by closely observing the roughness, flatness and tooth angle, seat surface and surface morphology before and after the test. The test results were used to calculate axial force ratio and anti-loosening ratio to understand the wear properties and anti-loosening properties of precision locknut under the dynamic conditions.

Abstract: PCD diamond cutting tools which named sintering diamond tool is the main cutting tool of the natural granite, the cutting characteristics of that have great influence on machining efficiency and machining quality. At present, most scholars are relatively mature on the research of diamond tool wear condition by the physical attributes of the PCD diamond tool and physical components of natural stone material. This paper studies the impact of cutting parameters on the tool wear, optimization of process parameters.

Abstract: Based on the motion characteristics of mechanical oscillating parts, a wear test machine is developed with single drive biaxial rotational oscillating, which can effectively simulate multiaxial rotational oscillation of mechanical oscillating parts and take different kinds of friction couplings wear test. Based on this design, the tribological property of easy wearing material in mechanical oscillating parts is studied and corresponding sphere-block test method is established. Pilot test and demonstration are taken to evaluate the sphere-block test method from feasibility, practicality, reliability and economy aspects. The results are meeting test requirements of tribological property under the condition of composite motion.

Abstract: The stress field distribution and change law of the friction surface are analysed in order to get the mechanism and characteristics of the wear pairs. The theoretical stress model of pin-on-disc pairs are observed according to the model of elastic half-space and the finite element model of it is built using the software of ABAQUS. The boundary condition and load are set and the stress change of the stationary state ,running-in period and stable situation are analysed respectively. The Mises stress ,contact stress and friction in different period are described and compared according to the simulated result of the finite element model.The experiment result shows the same characteristics of the simulation, so the advise is given to improve the frictional performance of the pin-disc pairs.

Abstract: Face cutting of tungsten carbide was conducted using two monocrystalline diamond tools and three polycrystalline diamond tools to investigate the wear characteristics in terms of the crystal structure and composition of the diamond. It was found that the wear of the monocrystalline diamond tool depends on the crystal planes that form the rake face and flank face of the cutting tool, and a cleavage fracture occurs when the cutting force acts as a shear force on the (111) crystal plane. The binderless nano-polycrystalline diamond tool exhibits excellent wear resistance beyond those of the sintered polycrystalline diamond tool and chemical vapour deposition polycrystalline diamond tool, as well as better wear resistance than the monocrystalline diamond tool.

Abstract: Thermal spray technology provides wear-resistant coating on the surface of mechanical components. In this study, wear characteristics of SiCp reinforced Al matrix composite coatings were evaluated. SiCp reinforced Al matrix composite coatings were fabricated using the mixed powders which have different fraction of the SiC reinforcement, 0, 20, 40 and 60 vol% on Al 6061 substrate by thermal spray process. Dry sliding wear tests were performed on these coatings using varied sliding speeds and applied loads. Wear behavior of these Al-based composite coatings were investigated using scanning electron microscope(SEM), energy dispersive X-ray spectroscopy(EDX) and X-ray diffraction(XRD). The composites coatings reinforced with 40 vol% of SiC particles showed the most excellent wear resistance. Although the wear rate increased according to the increase in the applied load, it decreased according to the increase in the sliding speed. The major wear behavior of the SiCp reinforced Al matrix composite coatings is transferred from the adhesive wear to the abrasive wear according to the increase in the sliding speed and the applied load. These results were significantly influenced by the formation of mechanical mixed layer(MML).