Papers by Keyword: Wear Debris

Abstract: Wear is a persistent industrial problem caused by the interaction of many interlocking and complex elements. CuZn37Pb2 and AA 6061 are particularly prone to wear due to their numerous industrial applications. To address this problem and contribute to the scientific literature, a comprehensive experimental investigation was conducted to understand and analyze the impact of these interconnected factors. This research developed a dry and lubricated horizontal lathe wear test apparatus. Various parameters, including contact temperature, wear loss, wear rate, and friction coefficient, were compared across different initial surface roughness levels, loads, sliding speeds, wear track diameters, and track widths. Experiments were performed at torques ranging from 25 to 100 N, speeds of 0.30, 0.40, and 0.50 m/s, and wear track diameters of 4, 6, 8, and 10 mm. SEM-EDS, XRD, and optical microscopes were used to examine each sample's worn surfaces and wear tracks. The morphological structure of the sample and the type of test have distinct impacts on the tribological response of the surfaces, each of which interacts uniquely, with influence varying depending on the tribological parameters. Generally, secondary phases (AA 6061) can lead to improved wear resistance due to their harder and more wear-resistant nature compared to the primary aluminum matrix. Conversely, the alpha phase of CuZn37Pb2 is harder and stronger than the beta phase and thus has better wear resistance properties. The error in wear rate calculations is 58.6% in both tests. The findings indicate that the tribological response in ideal laboratory conditions differs from that in actual field environments. This research provided significant insights into understanding and analyzing wear by addressing the largest number of characteristics previously unexplored. Additionally, the findings revealed that while completely eliminating wear is challenging, it can be significantly reduced. Laboratory wear experiments can be extrapolated to field wear tests, offering prototypes for industrial challenges and linking academic research with industry issues.

Abstract: Several machine components including a part of electrical circuit box, an electrical motor and an automotive part were common ferromagnetic materials used under the magnetic fields. In the general, their friction had occurred in the magnetized materials during operation. The friction coefficient of the sample under magnetic fields was different from the sample without magnetic field treatment. Its friction coefficient had correlation with wear behavior of specimens. The wear protection procedures for the ferromagnetic parts during operation are recognized different from others without magnetization. Its friction coefficient was thus used to measure the wear characteristics with a ball on disc friction tester. The microstructure of wear trace and debris was investigated by scanning electron microscope. From the results, the magnetic fields affected the change of friction coefficient. The friction coefficient was decreased with an increasing magnetic intensity. This was because the wear debris was induced and thus decreased the adhesive wear mode during friction test.

Abstract: A series of wet braking tests has been performed using two different pad materials. Brake tests were conducted in different operating conditions i.e. dry, humid air and wet environment in which both pad samples were tested against grey cast iron disc at certain sliding speed and contact pressure. Wear analysis was performed to find correlation between presence of water and changes in brake pad wear characteristics. The results revealed that regardless of the frictional behaviour, wear rate for both pad materials tested at humid air and wet braking is significantly lower than in dry results.

Abstract: The contribution deals with use of semi-automated method of magnetic separation of particles in order to control mechanical system of aircraft engines. There are three levels of machine wear characterized by means of wear debris particle analysis in the lubrication system of aircraft engines. The shape and size of wear debris particles formed due to machine wear arise immediately in case of wear change thus this method is extremely suitable to control mechanical system washed by lubricant. Analysis of actual samples of lubricating oils containing several types of wear debris at the same time resulted in finding out and characterizing the levels of wear, from standard up to critical one. The contribution describes typical types of aircraft engine lubrication system wear with allocation of the wear level to particular pictures of wear debris particles.

Abstract: Tool wear is a problem in machining nickel-based superalloy Inconel 718, and it is thus of great importance to understand and quantitatively predict tool wear. The experiments of machining Inconel 718 with cemented carbide tools (uncoated and coated) were carried out. Some new observations and analysis of tool wear through CCD, SEM and EDS were done. The results showed that at low cutting speed, the built up edge (BUE) formed easily and dropped at last which caused severe cutting tool breakage. When cutting speed came to 30m/min, the main reason that caused cutting tool wear was that the tool material fell off from the tool body at the form of wear debris. What’s more, the element diffusion between tool and workpiece and oxidation reaction all accelerate the formation and the cast of the wear debris.

Abstract: The oil condition monitor asks for wear derbies moving into the oil thin cavity stably which is on wear derbies image collecting apparatus, and reduces some phenomena of the wear derbies, such as roll, deposition and self-lock characterization, in order to enhance the quality of wear derbies image. This paper has first studied about the moving video image of the wear particles in an oil thin cavity. A qualitative research on the movement of the wear derbies, such as roll, deposition and self-lock characterization, has been investigated. Then dynamics of wear derbies is analyzed .The paper presents apparatus to avoid the overlap and jam of wear debris on the basic of the result of dynamics analysis. The oil thin cavity is considered to be laid vertically during the experiment.

Abstract: This paper examines the friction behaviour of AlCrN and TiN PVD coatings in atmospheric air and vacuum using a ball-on-disc and a reciprocating tribotesters. Comparative study on the coating sliding in air and in high vacuum environment provides important insight on the effect of oxidation on the friction behaviour of the coatings. Other important factors such as load, sliding velocity, temperature effects on the frictional behaviour of these coatings were also investigated. In the ball-on-disc tests carried out in vacuum, (i) TiN gave lower coefficient of friction (COF) than AlCrN, indicating that TiN was more lubricous, (ii) higher speed resulted in lower COF, and (iii) the COF of both coatings were lower than that produced in air. In ambient air, (i) AlCrN gave lower COF than TiN with high wear debris retention on the sliding interface due to the effect of oxidation, and (ii) higher speed resulted in lower COF, similar to that observed in vacuum. In the reciprocating tests, at low load, increasing the temperature from room temperature to 150 °C resulted in a reduction in the COF. However, at high load, the temperature virtually did not affect the COF. Higher nominal load resulted in lower COF while higher speed resulted in higher COF.

Abstract: Aeroengine oil contains wear debris generated by friction. Based on the Dempster-Shafer evidence combination theory, aeroengine wear conditions can be effectively diagnosed. Through analysising the elements of wear debris in lubricating meduim, it can determine engines wear levels and wear parts, as references for troubleshooting. In the process of combination, an method was proposed that every element of wear quantity and wear rate were fused at first,then the integration of all elements. For Dempster-Shafer has its own limitations, two impoved methods were applied to and were compared. The results show that Dempster-Shafer evidence combination is an effective fault diagnosis method for aeroengine oil wear condition.

Abstract: Wear debris recongition system is researched,which is based on adaptive resonance theory of artifical neural network(ART) and gray level co-occurrence matrix.The ditailed process is as follows:the first,according to gray level co-occurrence matrix theory,wear image refining feature parameter algorithm is researched; the second,in order to solve the wear debris classification,which is built on the wear image refining feature parameter algorithm, wear debris classification ART algorithm is researched;at last,a series of experiments,which is based on the algorithm,are processed.The theroy derivation and experiment results prove that the wear debris recongition system is feasible in recognition accuracy and algorithm convergence speed.

Abstract: According to the qualitative characterization of the morphological features of the wear debris, Feature vector mathematics model of wear debris are built,which are based on Foruier parameter refining methord.Then the advantages of fuzzy system and neural network are taken to establish a kind of improved fuzzy neural network (IFNN) models and algorithm.which is used to realize the automatic classification and recognition of wear debris. An improved learning algorithm with the modified fuzzy weight is proposed on the basis of the fuzzy neurons model for the max-min fuzzy operator. The amount of calculation for the improved FNN model is reduced greatly and the convergence velocity is improved. At last ,the experiment results show that the recognition method based on the IFNN is good at algorithm convergence speed and recognition accuracy.