Experimental Wear Data Research Articles

An adaptive RUL prediction approach for cutting tools incorporated with interpretability and uncertainty

Reliable prediction of tool Remaining Useful Life (RUL) is essential for ensuring machining quality and promoting sustainability, serving as a key component of high-performance machining. Traditional approaches face significant challenges in addressing uncertainties and ensuring interpretability during machining processes. To predict the RUL of tools in scenarios with small, unlabeled datasets and to quantify uncertainty in degradation models, this paper presents an adaptive RUL prediction method based on multi-source data fusion and Bayesian inference. Specifically, an adaptive Bayesian iterative updating model, grounded in the degradation process of cutting tools is proposed. This model operates without the need for extensive labeled samples or offline training, while incorporating both interpretability and uncertainty. Furthermore, Bayesian inference, combined with delayed rejection and adaptive Metropolis-Hasting strategies, is employed to update uncertainty parameters in degeneration model. This enables the degradation model adaptively approximate the actual wear tread in real-time through continuous observation. The proposed method is validated using experimental tool wear data, demonstrating reductions in average RMSE of 27.00% and 11.60% compared to other approaches. Notably, it does not depend on large historical datasets with labels and effectively mitigates the impact of uncertainties, offering a novel approach to RUL prediction in the real industrial applications.

Evaluation of Wear Model Equations Through Analysis of Experimental Wear Data of Materials from Literature

Understanding the correlation between material characteristics and wear behavior helps in the development and manufacturing of high-quality materials for components subjected to wear, like brake pads, bearings etc. The majority of published research papers present experimental data from pin-on-disc experiments in which wear volume loss is measured using wear rate and sliding distance. However, in many publications pin on disc experimental data is interpreted by statistical methods like Taguchi method to understand the effect of material characteristics on wear behavior. This method indirectly correlates wear behavior to material parameters like hardness, modulus of elasticity and toughness of the material. However, many mathematical models are proposed in literature to directly relate material characteristics to wear behavior. However, there are gaps in published literature in interpretation of experimental data with mathematical model equations. The mathematical models like Archard model, Evans and Wilshaw model, Kato model etc proposed in literature are defined to link material characteristics like modulus of elasticity, hardness, toughness etc to wear behavior. In this study, it is proposed a methodology to interpret the pin on disc experimental wear data by fitting an analytical model to understand effect of material characteristics on wear behavior of materials.

+Fretting wear: A phenomological approach

An analytical description of fretting wear is proposed wherein the volume of wear debris either removed from the sliding interface or retained within these areas, is represented as a fraction of the freshly-produced debris in each fretting pass. In the proposed model, the volumes respectively of removed debris and of retained debris are tallied over each pass of a fretting sequence to yield a closed analytical expression relating these volumes to the number of passes. The paper provides an example of the adaptation of the proposed model to experimental wear data on steel-steel fretting interfaces.

Accelerated tribological testing based life prediction of aluminium-graphite tribo composite

Electrical sliding contacts in electrical motors and generators are subjected to severe friction and wear conditions. Conventional materials such as carbon and electrographite do not have longer life due to the generation of carbon dust. This creates environmental pollution and also affects the operation of an electrical machine. Aluminium-graphite composites are well suited for such applications. However, the life of the components made out of aluminum-graphite composite is to be evaluated in order to optimize their performance at the design stage itself. Traditional life data analysis at normal usage conditions is time-consuming. In the present study, aluminum-graphite composites were manufactured through the energy-efficient microwave sintering, and the life of components was estimated using Accelerated Life Testing (ALT) procedure. The experimental wear data were analyzed using an inverse power law model. Reliability and failure rate models were developed using the time-to-failure data. Life at normal usage conditions was predicted using these models. The calculated reliability at normal usage conditions was more than five years at a 99% confidence limit.

Uncertainty-based comparison of conventional and surface topography-based methods for wear volume evaluation in pin-on-disc tribological test

Precise wear evaluation is essential to develop prediction models, applied to design materials, components and to optimise new manufacturing processes. Pin-on-disc is a widespread standardised conventional sliding wear test. Conventional characterisation of resulting wear exploits gravimetric or profilometric techniques. These have inadequate precision and accuracy for applications characterised by low-wear and uneven morphology and are being replaced with high-resolution and information-rich inspections to measure surface topography. Metrological characterisation of topography-based methods still lacks in literature, which prevents the performance comparison with conventional techniques. This paper develops a framework to evaluate topography-based methods’ measurement uncertainty and compare methods’ performances accordingly on experimental wear data on PTFE and Aluminium. Results show that topographic methods improve pin-on-disc characterisation’s reliability.

Evaluation of Wear Behaviour in Metallic Binders Employed in Diamond Tools for Cutting Stone.

A type of disc-on-plate test methodology was used to determine the wear behavior of metallic binders employed in the manufacturing of diamond impregnated tools. The disc consists of a special circular wheel that allows the binder materials alone (i.e., without diamond, but sintered under conditions identical to those of the complete tool) to be tested against a plate of stone material under pre-determined testing conditions. The testing conditions are intended to be equivalent to those used in the industrial processes. Using plates of five types of granite and one type of marble, this work comprises wear tests of 15 different types of metallic binders and two sintering modes conducted under, at least, three different values of contact-force. The analysis of the results demonstrated that the wear of the binders can be related to their mechanical properties through an empirical expression. The larger the difference between the characteristics of the tribological pair (binder versus stone), the higher is the correlation between the experimental wear data and the values given by the empirical expression. The relationships presented in this work allow predicting the wear behavior of the binder, and therefore may help in the design process of diamond tools. There was a clear difference between the wear behavior of metallic binders when they were employed against the two main classes of stone under analysis (marble and granite).

Tribological Properties of 10-Undecenoic Acid-Derived Schiff Base Lubricant Additives

Four 10-undecenoic acid-based Schiff bases were synthesized by condensation of methyl 11-(2-aminoethylthio) undecanoate with various aromatic aldehydes. Synthesized compounds were characterized by spectral techniques and evaluated for their tribological and antioxidant performances in biolubricant base oil, namely epoxy 2-ethyl hexyl esters of karanja fatty acids. The tribological test results indicate that all the synthesized thioethers containing Schiff bases act as good antiwear and extreme pressure additives. A significant reduction in wear scar diameter was observed at a very low concentration (0.6 wt%), whereas, at 1 wt% concentration, weld point enhancement observed from 160 to 230 kg. Quantum chemical calculations based on density functional theory for the interactions of Schiff bases with surfaces correlated with experimental wear data. Overall, the dimethoxy-substituted phenyl ring containing Schiff base was more effective in enhancing the antiwear and extreme pressure performance of base oil, whereas dihydroxy-substituted phenyl ring containing Schiff base exhibited good antioxidant property.

A hybrid model for wear prediction of a single revolute joint considering a time-varying lubrication condition

Wear of revolute joints critically influences the service life and maintenance of certain types of machinery. As a result, many methods have been developed to investigate the wear of revolute joints based on the assumption of either dry contact or full-film lubrication. However, in real applications, a revolute joint may operate under different lubrication conditions during its lifecycle. In this paper, a hybrid model is proposed for wear prediction of a single revolute joint that may experience different lubrication conditions. Three lubrication conditions are considered: full-film lubrication, boundary lubrication, and dry contact. A time-varying wear coefficient is introduced to represent these different lubrication conditions. In our hybrid model, the Archard wear model is used. An adaptive finite element model is used to perform wear simulation of a single revolute joint by continuously updating the contact nodes. In the finite element model, two friction coefficients are used to take into account the change of lubrication conditions. To achieve more accurate predictions and reduce uncertainties of the wear coefficient, the Bayesian updating method is implemented using experimental wear data. The proposed approach is tested using wear experiments of a revolute joint used in an airplane cabin door. The journal material in this experiment is 0.45C steel and the bearing material is brass H58. A comparative study was also conducted between the proposed approach and two other methods. Results show that the proposed approach can more accurately predict the remaining useful life of a single revolute joint.

Adsorption of lubricity improver additives on sliding surfaces

Lubricity improver additives are adsorbed on sliding surfaces and form boundary films. Although for most additives, the films are monolayers, multilayer adsorption does occur in tribological contacts. However, to date, the isotherms adopted to study the adsorption thermodynamics for tribological systems are limited to monolayer films. To address this, the original Brunauer–Emmett–Teller (BET) gas adsorption isotherm was modified for use in dilute liquid solutions. The modified BET isotherm was used to fit experimental wear data collected using high frequency reciprocating rig (HFRR) for ultra-low sulphur diesel (ULSD) fuels containing trace levels of commercial lubricity improving additives. The results suggested that for certain additives in ULSD, the boundary film is multilayer.

Micropitting Fatigue Wear Simulation in Conformal-Contact Under Mixed Elastohydrodynamic Lubrication

In this study, a physics-based fatigue wear model is proposed to evaluate the reliability and to predict the life of cumulative micropitting wear for lubricated conformal contacts on rough surfaces. The surface normal load, mean film thickness, and frictional shear traction are simulated by a mixed elastohydrodynamic lubrication (EHL) model for a stress prediction model to calculate the average maximum Hertzian pressure of contact asperities and unit with the statistical contact model and dynamic contact model to obtain the asperity stress cycle number. The wear formula is established through combining a micropitting life prediction model of surface asperities and a mean micropitting damage constant of asperities. The four dominant aspects affecting wear behaviors of the surface contact pairs, working conditions, structure and surface topographies, material properties and lubrication conditions are all taken into account in the model. It is a high-fidelity and comprehensive model that can be used to analyze and optimize the tribological design of rolling–sliding pairs in machinery. The micropitting fatigue wear modeling scheme is validated by comparison of theoretical calculations and available experimental wear data.

Wear at high sliding speeds and high contact pressures

Metal on metal wear at high sliding speeds and high contact pressures results in the melting of one or both of the sliding solid bodies due to heat generated at the contact interface. Understanding the influence of sliding speeds and contact pressures on normalized wear rates is important in developing predictive models for designing more efficient and effective engineering system components. Typical engineering applications subjected to extreme sliding conditions include ultrahigh speed machining, rocket sleds, large caliber cannon, and electromagnetic launchers. Sliding speeds on the order of 1000m/s and contact pressures in excess of 100MPa are common in these applications and difficult to replicate in a laboratory environment. A unique electromagnetic tribometer based on a minor caliber electromagnetic launcher has been designed and implemented to characterize wear deposition of a 6061-T6 aluminum pin (slider) on a UNS C11000-H2 copper flat (guider) at sliding speeds from 0 to 1200m/s and contact pressures from 100 to 225MPa. Optical microscopy and 3D profilometry were used to investigate and quantify slider wear. Three distinct wear regions were observed. Test results provided evidence that the aluminum slider contact interface was molten and experimental wear data showed a dependence on both pressure and velocity. Comparisons between melt lubrication theory and experimental data provide insight into the nature of the contact interface under the sliding conditions tested.

Prediction of abrasive punch wear in copper alloy thin sheet blanking

This work presents a combination of finite element simulations of copper alloy thin sheet blanking and a wear algorithm based on Archard formulation for abrasive wear of the punch. Firstly, a tribometer has been specifically designed to measure wear coefficient, and punch worn profiles have been extracted by means of a double-print method. Secondly, the blanking process has been simulated through the finite element method by using an elasto-plastic constitutive model and the shear failure model. Thirdly, a wear algorithm has been programmed using experimental wear data and mechanical fields computed from blanking simulation. Then, a damage criterion, namely the shear failure model, has been calibrated by an original method based on stress triaxiality analysis and shear height value measured from blanked edge profile. Finally, punch wear predictions have been discussed and compared to experimental results.

An engineering approach for the prediction of wear in mixed lubricated contacts

The continuum damage mechanics (CDM) approach in conjunction with the load sharing concept is applied to predict steady state lubricated line-contact wear. Empirical formula for the maximum contact pressure in dry rough contact is employed together with the lubricant film thickness equation to estimate the portions of the load carried by the asperities and the lubricant. Effect of contact temperature on wear is also included using a simplified thermo-elastohydrodynamic analysis in conjunction with fractional film defect concept. While most wear models require experimental calibration, current study attempts to predict wear purely based on numerical simulation. The proposed methodology is quite fast and easy to implement for practical engineering applications. Comparison of numerical calculations with available experimental wear data show very good agreement.

Detect Tool Breakage By Using Combination Neural Decision System & Anfis Tool Wear Predictor

The original contribution of the research is the developed monitoring system that can detect tool breakage in real time by using a combination of neural decision system and ANFIS tool wear predictor. The ANFIS method uses the relationship between flank wear and the resultant cutting force to estimate tool wear. Therefore, the ANFIS method is used to extract the features of tool states from cutting force signals. A neural network is used in tool condition monitoring system (TCM) as a decision making system to discriminate different malfunction states from measured signal. A series of experiments were conducted to determine the relationship between flank wear and cutting force as well as cutting parameters. The forces were measured using a piezoelectric dynamometer and data acquisition system. Simultaneously flank wear at the cutting edge was monitored by using a tool maker’s microscope. The experimental force and wear data were utilized to train the developed simulation environment based on ANFIS modeling. By developed tool condition monitoring system (TCM) the machining process can be on-line monitored and stopped for tool change based on a pre-set tool-wear limit.

Electrochemical Simulation of the Current and Potential Response in Sliding Tribocorrosion

Valuable insights into the wear-corrosion behavior of metals, as well as into the tribocorrosion field through the development of simulation models of tribocorrosion experiments, can contribute in rationalizing wear-accelerated experiments and their open circuit potential (OCP) behavior under rubbing. These results demonstrate that mathematical models of controlled tribo-electrochemical contacts can complement the physical experiment and add valuable understanding to the tribological behavior of metals, alloys, and generally to materials in an electrochemically active environment. The excellent agreement of experimental wear data and the experimental OCP curves with the OCP simulations with time establishes the concepts underlying the galvanic coupling model as a valid methodological approach toward a quantitative description and mechanistic understanding of the tribo-electrochemical experiment. Besides analyzing stellite tribocorrosion, application of the model to Al alloy data has helped us quantify the relative contributions of chemical and mechanical wear and reveal the underlying synergy. Ti metal tribocorrosion under variable load has revealed that the contact pressure P av, can reach much lower values within the experimental time domain and finally be the cause of interruption of the initial wear mechanism.

Real-Time Cutting Tool Condition Monitoring in Milling

Reliable tool wear monitoring system is one of the important aspects for achieving a self-adjusting manufacturing system. The original contribution of the research is the developed monitoring system that can detect tool breakage in real time by using a combination of neural decision system and ANFIS tool wear estimator. The principal presumption was that force signals contain the most useful information for determining the tool condition. Therefore, the ANFIS method is used to extract the features of tool states from cutting force signals. ANFIS method seeks to provide a linguistic model for the estimation of tool wear from the knowledge embedded in the artificial neural network. The ANFIS method uses the relationship between flank wear and the resultant cutting force to estimate tool wear. A series of experiments were conducted to determine the relationship between flank wear and cutting force as well as cutting parameters. Speed, feed, depth of cutting, time and cutting forces were used as input parameters and flank wear width and tool state were output parameters. The forces were measured using a piezoelectric dynamometer and data acquisition system. Simultaneously flank wear at the cutting edge was monitored by using a tool maker’s microscope. The experimental force and wear data were utilized to train the developed simulation environment based on ANFIS modelling. The artificial neural network, was also used to discriminate different malfunction states from measured signals. By developed tool monitoring system (TCM) the machining process can be on-line monitored and stopped for tool change based on a pre-set tool-wear limit. The fundamental limitation of research was to develop a singlesensor monitoring system, reliable as commercially available system, but 80% cheaper than multisensor approach.

Compact core drilling in basalt rock using PCD tool inserts: Wear characteristics and cutting forces

Abstract The hardest component of the Martian surface is believed to be basalt rock, which is highly abrasive in nature. It will be important to operate a Martian drill under conditions that are conducive to minimal tool wear. In preparation for a Mars drilling project, this paper reports results of an experimental study of dry drilling in basalt and related tool wear. It also reports the effect of the tool wear on increasing the forces and torques required when drilling in basalt rock (on earth) using polycrystalline diamond (PCD) compact core drill inserts. Force and torque data measured for a variety of cutting conditions are shown along with experimental wear data obtained while drilling in basalt rock having different strengths. It is found that flank wear, VB, and cutting edge radius, CER, wear rates increase with rock strength, VB-wear rates and CER-wear rates exhibit opposite trends in their dependence on the remainder of the cutting parameters. For example, while VB-wear rates decrease with an increase in tool feed and spindle speed values, CER-wear rates increase with increases in tool feed and remains unchanged with increases in spindle speed. VB-wear rates decrease as the rake angle becomes more negative, while CER-wear rates increase as this occurs. It is found that basalt rock strength manifests itself via larger (smaller) generated forces/torques for rocks of harder (softer) composition. Strong correlations are found between both modes of tool wear (VB and CER) and the measured values of thrust force and torque. Equations for progressive tool wear as functions of the process variables are developed. A model for the changing drill forces and torques required by the progressive tool wear is developed for drilling in basalt.

Influence of cenosphere filler additions on the three‐body abrasive wear behavior of glass fiber‐reinforced epoxy composites

AbstractThe dry three‐body abrasive wear behavior of bi‐directional glass fabric reinforced epoxy composites with and without cenosphere filler have been studied using dry sand/rubber wheel abrasion tester. The angular silica sand particle sizes in the range 200–250 μm were used as dry and loose abrasives. The wear experiments have been conducted at two different loads viz., 22 and 32 N and different abrading distances viz. 270, 540, 810, and 1,080 m. The wear volume increases with an increase in load/abrading distance for all composites. From the experimental wear data it was observed that the abrasive wear of the composites dependent on the applied load and abrading distance. Further, the cenospheres filler inclusion in glass fiber reinforced epoxy (G‐E) composite showed poor abrasive wear performance. Scanning electron microscopy was used to study the morphology of the worn surface features of composites and to understand the mechanisms involved in the wear analysis. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

Modeling transient adhesive wear of tungsten carbide inserts tested with an angular setting

The standard transient adhesive wear equation had been used for modeling pins tested with a full contact with a counter disc. The wear volume against distance curve (wear curve) obtained from such a test can be divided into two regimes: the curvilinear transient regime and the linear steady-state wear regime. The slope of the wear curve at the beginning is a lot higher, and it gradually decreases with sliding distance towards the steady-state wear regime. On the other hand, for inserts tested with an angular setting, generally, the wear curve is in the form of a straight line with a constant slope. This is due to the limited volume of asperities available for wear initially, but as wear progresses, the volume of asperities available will also increase. Generally, the volume loss of inserts with an initial angular setting with the counter disc is lower, as compared with those obtained with a full contact setting. The wear volume also increases with load, speed and temperature. As the wearing conditions for both cases are different, a new exponential transient adhesive wear equation has, therefore, been developed to model the transient wear volumes of tungsten carbide inserts tested with an angular setting. Excellent results with an average correlation coefficient of 0.9964 and an average deviation of about 10% are obtained. Inferior results are obtained when the standard transient adhesive wear equation is used for modeling the inserts with an angular setting, as the assumption made in its derivation is no longer applicable. The modeling results obtained from using both equations, as well as some evidence obtained from SEM and optical examinations of the worn inserts and wear tracks will be discussed in details in this paper. The experimental wear data used to support this modeling work are obtained earlier from a high temperature wear testing rig, in which Sandvik tungsten carbide inserts are tested with an angular setting with a hot work tool steel counter disc. The experimental parameters used are: (i) Applied loads of 40 and 50 kgf, (ii) speeds of 100 and 130 m/min, (iii) temperatures of 25, 200, 400 and 600 °C, and (iv) distances from 1000 m to 16,000 m.

A Fracture Mechanics Approach to the Prediction of Tool Wear in Dry High Speed Machining of Aluminum Cast Alloys—Part 2: Model Calibration and Verification

Background. Aluminum alloys are extensively used in the automotive industry and their utilization continues to rise because of the environmental, safety and driving performance advantages. Experimental study has been carried out in this work to establish the effect of cutting conditions (speed, feed, and depth of cut) on the cutting forces and time variation of carbide tool wear data in high-speed machining (face milling) of Al–Si cast alloys that are commonly used in the automotive industry. Method and Approach. The experimental setup and force measurement system are described. The cutting test results are used to calibrate and validate the fracture mechanics-based tool wear model developed in part 1 of this work. The model calibration is conducted for two combinations of cutting speed and a feed rate, which represent a lower and upper limit of the range of cutting conditions. The calibrated model is then validated for a wide range of cutting conditions. This validation is performed by comparing the experimental tool wear data with the tool wear predicted by calibrated cutting tool wear model. Results and Conclusions. The maximum prediction error was found to be 14.5%, demonstrating the accuracy of the object oriented finite element (OOFE) modeling of the crack propagation process in the cobalt binder. It also demonstrates its capability in capturing the physics of the wear process. This is attributed to the fact that the OOF model incorporates the real microstructure of the tool material. The model can be readily extended to any microstructure of Al–Si workpiece and carbide cutting tool material.