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• The mechanical model for the axial thrust force between the rolls is proposed. • The proposed cross modes are applied to various typical strip mills. • A novel calculation method for the axial thrust force is developed. • An industrial test rig is built at an industrial plant to record the real-time axial thrust data. Theoretical predictions and engineering practice indicate that roll crossing in strip mills can generate an excessive axial thrust force between rolls, often resulting in roll bearing failures and a lower strip surface quality. Although this effect is important in design of strip mills and manufacturing, the existing literature refers only to simple formulas and manual measurements for evaluating this axial thrust force. In this work, a novel approach to model the axial thrust force considering tangential deformations of the rough surface layer and the matrix is proposed to calculate the axial thrust force for various typical strip mills. In addition, data from an industrial test rig at the production site taken to examine the real-time axial thrust force during roll crossing. The results indicate that under light load conditions, the axial thrust force can be accurately predicted by considering only the tangential deformation of the rough layer surface, whereas for heavy loads conditions, the tangential elastic deformation of the matrix must be taken into account as well. The axial thrust force approaches sliding friction force limit for crossover angles smaller than 0.1°. In general, the axial thrust force grows with increasing crossover angle, which is confirmed by both theoretical and experimental results. [Display omitted] [ABSTRACT FROM AUTHOR]

A synergistic Al 2 O 3 /GO hybrid nanofluid was developed, aiming to attain prominent tribological properties for application in mechanical engineering. On the support of a molecular dynamics approach, amorphous models were simulated, thus illustrating the agglomeration or the adsorption in nanofluids, as well as revealing the evolution of the laminated adsorbed structure. Further, single-component or hybrid nanofluids were characterized and their tribological validations were performed. The results showed that the modified nanofluids realized dispersion equilibrium and suspension stabilization at the molecular level, and their wettability or thermo-physical indexes were improved, which was beneficial for the tribological performance. Especially in hybrid nanofluids, the synergistic effect further enhanced these capabilities, thereby maintaining a small friction coefficient and a flat wear region. [ABSTRACT FROM AUTHOR]

• The proposed method has the generalization capability between different sensing channels. • A comprehensive evaluation method of model performance is proposed. • The performance difference between different sensing signals is reduced. • The limitation of the single-channel signal is overcome. • The effectiveness of the method is verified by two experimental cases. Real-time and accurate monitoring of tool wear conditions is crucial to achieving double optimization of production cost and product quality. However, the differences in the characteristics of different signals limit the ability of the monitoring model to generalize between sensing channels, which becomes an important factor limiting the promotion of the model. To solve this problem, an improved parallel residual network based on single-channel and non-specific sensing signals is proposed in this paper. The limitation of the single-channel signal with little information and poor anti-interference ability is overcome by adaptively extracting the multi-scale spatial features of the sensing signal. Hybrid dilated convolution is introduced to expand the receptive field, and then the long historical domain information is obtained. At the same time, the information dependence between layers is enhanced by introducing skip connections. These two designs ensure the perceptual generalization ability of the model. Considering the tool replacement time and the imbalance classification of labels, a comprehensive evaluation method is proposed for model performance evaluation. In addition, the variation law of tool wear in the milling process of Ti-6Al-4V thin-walled parts is investigated. Finally, the validity and transferability of the model are verified by two milling datasets with different cutting conditions. On the basis of ensuring the perceptual generalization ability of the model, the differences in model performance based on acceleration and cutting force signals are controlled within 4.5 % and 1 %, respectively, and the overall average recognition performance is 96.3 % and 92.5 %, respectively. This study provides a feasible solution for intelligent tool replacement in the actual machining environment. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A pixel-level quantification model of grinding-introduced microcrack is proposed. • Using the joint Mask R-CNN and TransUNet model to detect and segment microcracks. • Challenges in quantifying size are tackled by the skeleton-based quantification model. • The evolution of microcracks with grinding parameters is quantitatively presented. Microcrack damage on the grinding surfaces of engineering ceramics is inevitably incurred. To accurately evaluate the microcrack damage, an automatic detection and pixel-level quantification model based on the joint Mask R-CNN and TransUNet is developed. In addition, a joint training strategy is employed and the model is trained effectively on the image dataset of microcrack damage derived from the Si 3 N 4 grinding, as captured by SEM. The Mask R-CNN demonstrates reliable automatic detection of microcracks, achieving an Average Precision of AP 50 = 0.989 and AP 75 = 0.864. Meanwhile, the TransUNet achieves fine segmentation of microcracks with complex characteristics, with an F1 score of 0.914 and an IoU value of 0.785. A skeleton-based quantification model of microcrack size is proposed, which delivers comprehensive and precise measurements of area, length, and notably, the width. The proposed quantification model provides a technical reference for the automatic evaluation of grinding surface quality. [ABSTRACT FROM AUTHOR]

Highlights • The long-range interaction between solute hydrogen and crack is analytically studied. • The stress field of a dilatation line near an elliptical void in an infinite matrix is analytically obtained. • The solute atoms trapped ahead of crack tips have a total anti-shielding effect on crack tips. • A new possible mechanism of hydrogen embrittlement referred to as "hydrogen induced anti-shielding crack mechanism" is proposed. Abstract A two-dimensional elastic solution for the stress field of a dilatation line near an elliptical void in an infinite matrix is obtained. The dilatation line is used to represent a row of equally spaced solute atoms. This elastic solution is employed to study the shielding or anti-shielding effect of solute atoms near a finite length crack. The stress intensity factor of stress field induced by a dilatation line is analytically obtained. It is shown that whether solute atoms have a shielding or anti-shielding effect on the crack tips depends on the position of solute atoms. An equaling zero curve is defined, on which the solute dilatation line induces zero Mode I stress intensity factor at the crack-tip. It is found that the shape of equaling zero curve is independent of any model parameters. The shielding and anti-shielding effects of a lot of solute hydrogen (hydrogen atmospheres) are studied through an integral scheme. The hydrogen concentration field is assumed to equilibrate with external or internal stress fields. We consider two cases. One case is that an externally uniaxial load in the direction vertical to crack is applied. Another case is that there exists an edge dislocation near crack. Based on these studies, a new possible mechanism of hydrogen embrittlement is proposed, which can be referred to as hydrogen induced anti-shielding crack mechanism. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

Highlights • Cylindrical system of vector functions. • Transversely isotropic diffusive bimaterials. • General concentrated dislocations and diffusive source. • Analytical Green's function solution. • Effect of diffusive coefficients on the dislocation field. Abstract While the fundamental solutions of concentrated forces and dislocations in purely elastic media are available for various applications, solutions in the corresponding diffusive materials have seldom been derived due to the involved complexity. In this paper, in terms of the cylindrical system of vector functions and under the assumption of steady-state deformation, we derive analytically the elastic and diffusive fields induced by the concentrated forces and dislocations which are located on the interface of a transversely isotropic and diffusive bimaterial space. Solution of the concentrated diffusive source has been also derived. These solutions can further be reduced to the corresponding isotropic bimaterial case and the transversely isotropic full-space case. Based on the newly derived solutions, field quantities induced by different concentrated dislocation sources are presented numerically to demonstrate the effect of the diffusive coefficients, material heterogeneity, and dislocation types on the induced fields. [ABSTRACT FROM AUTHOR]

Abstract A two-dimensional elastic solution for the stress field of a line dilatation near a circular inhomogeneity is obtained. A line dilatation is used to represent a row of solute atoms, referred to as a solute rod. The image effect is investigated with an especial attention. It is shown that a soft inhomogeneity attracts solute rods and a hard inhomogeneity repels solute rods. Based on this, the interactions of solute atoms with inhomogeneity-edge dislocation are studied by inserting more solute atoms into the matrix one-by-one, with an especial focus on the distribution of solute atoms (rods) around inhomogeneity and edge dislocation. As two typical applications of the present method, two simple cases are analyzed in details, with the inhomogeneity considered as a nano-void and a hard nano-fiber, respectively. It is shown that the equilibrium concentration distribution of solutes near an inhomogeneity is non-local, which not only depends on the local hydrostatic stress but also on the hydrostatic stress in the adjacent region. Besides, the shear stress on an edge dislocation, generated by hydrogen atmospheres between a circular nano-void/fiber and the dislocation, is calculated numerically. The results show that the hydrogen atmosphere around dislocations can shield the long-range elastic interaction between dislocations and other internal stress sources, supporting the so-called hydrogen enhanced localized plasticity. Graphical abstract Image 1 Highlights • A 2-D elastic solution for stress field of a line dilatation near internal stress sources is given. • The elastic inhomogeneity-dislocation-solute interaction is studied. • The solute atmospheres influences heavily the inhomogeneity-edge dislocation interaction. • The hydrogen enhanced localized plasticity mechanism is supported. [ABSTRACT FROM AUTHOR]

Constrained layer damper is widely used in engineering applications to suppress the severe vibration of structural systems, especially for the cases with moving loads, such as sandwich beam or sandwich plate. The response analysis and parametric analysis of these sandwich structures under moving loads have not still understood comprehensively. To do this, a hybrid approach based on extended Rayleigh-Ritz solution together with penalty method and differential quadrature method is presented to predict the dynamic responses of sandwich plate with isotropic face plate and a viscoelastic core subjected to moving loads. Both the energy terms related to the sandwich plate and the energy terms introduced by boundary conditions are derived based on the first order shear deformation theory (FSDT) and expressed using the Rayleigh-Ritz solutions, and then the governing equation of motion of sandwich plate is obtained through Lagrange equation, which can model a sandwich plate with various boundary conditions. Different with classical Rayleigh-Ritz solutions, the admissible functions adopted here is a set of combination of simple polynomials and trigonometric functions, which just satisfy a totally unconstrained boundary condition, and penalty method is applied to handle constraints. Then the variations of the natural frequency, associated modal loss factor and vibration response with the parameters (such as thicknesses of constrained layer and damping layer, elastic modulus of constrained layer material, and shear modulus and loss factor of damping layer material) of sandwich plate are studied. Moreover, the variations of maximum dynamic deflections with different boundary conditions as well as moving speeds are investigated. [ABSTRACT FROM AUTHOR]

Due to its low stiffness and time-varying modal parameters, thin-walled workpiece milling is still a challenging problem. In order to reveal the influence of the relative position between the cutter and workpiece on the dynamic response of the flexible thin-walled component, and optimize the parameters of the constrained layer damper applied to suppress the machining vibration in thin-walled workpiece peripheral milling process, with assumption of chatter-free milling operation, a dynamic model of thin plate peripheral milling with constrained layer damper subjected to moving cutting force using Lagrange equation is proposed based on the first shear deformation theory. Considering the complexity and variability of the boundary conditions of workpiece in practical machining processes, a mixed Rayleigh-Ritz solution together with Courant's penalty method and differential quadrature method is presented to evaluate the damping performance and dynamic response. Courant's penalty method is used to handle the complex and changing boundary conditions, Rayleigh-Ritz method is employed to deal with the spatial partial derivatives, and differential quadrature method is applied to treat the temporal derivatives. The influence of the relative position between cutter and workpiece on dynamic response is investigated, and the response of milling position are calculated using presented technique and compared with the results measured through milling tests. The results show that an acceptable agreement between numerical and experimental results can be obtained and the present technique is efficient to estimate the dynamic response of thin plate milling. Additionally, the parametric study of constrained layer damper is performed through evaluating the root-mean-square of response, and the results can be used to optimize the parameters of the constrained layer damper for suppressing machining vibration and improving surface finish accuracy. [ABSTRACT FROM AUTHOR]

A hybrid method is proposed to predict the dynamic behavior of functionally graded (FG) plate subjected to a moving mass. The governing equations of motion of FG plate are derived using the Kirchhoff plate theory and Lagrange equation. Improved Rayleigh–Ritz solution is used to treat the spatial partial derivatives. Penalty method is employed to deal with the constraints, and the energy terms due to boundary conditions are included in Lagrange, hence it is not necessary to particularly consider the constraints in the modeling process. And the combination of simple polynomials and trigonometric functions is selected as the admissible functions. The advantage of this improvement in Rayleigh–Ritz method is that it is not needed to find satisfied admissible functions for different boundary conditions while the convergence of the solution is improved. Meanwhile, the method can be used to handle the versatile boundary conditions. Differential quadrature method (DQM) as a step-by-step time integration scheme is employed for discretization of temporal derivatives. The validated results show that the presented method is very reliable and efficient, and its convergence and accuracy are also better compared to finite element method for solving the dynamic problems of FG plate with moving loads (force and mass). Moreover, the influences of material properties and boundary conditions on maximum dynamic deflections are investigated, as well as moving speeds and inertial effects of loads (mass and force). Although only four edge boundary conditions are addressed in the present work, the proposed procedure is applicable for any arbitrary edge boundary conditions. [ABSTRACT FROM AUTHOR]

High efficiency and high precision milling of thin-walled component (such as turbine blade) is still a challenging problem due to the weak rigidity and time-varying modal parameters of workpiece, as well as the complex cutting tool path. In this paper, the dynamic response of a thin-walled component with variable thickness in milling process is discussed based on the first shear deformation theory and Lagrange equation. The mixed Rayleigh-Ritz solution together with penalty method is presented to evaluate the spatial partial derivatives and boundary conditions. The influences of the thickness of plate and the cutter moving path on deformation of component are investigated, and milling experiments of thin-walled part are performed to verify the accuracy and efficiency of the presented method. [ABSTRACT FROM AUTHOR]

A comprehensive method is proposed to predict the dynamic behaviors of flat plate of arbitrary boundary conditions subjected to moving loads, based on Kirchhoff plate theory. The governing equations of motion are derived using the Lagrange equation. Rayleigh–Ritz method is employed and extended to treat the spatial partial derivatives. Different with conventional Rayleigh–Ritz solutions, the admissible functions adopted here integrate the advantages of both polynomials and trigonometric functions, which just satisfy a totally unconstrained condition, and Courant's penalty method is used to handle constraints. Differential quadrature method is used for discretization of temporal derivatives. The results show that the presented method is very reliable and efficient, and its convergence and accuracy are also better compared to finite element method. Moreover, the method is good for dealing with the boundary conditions due to employing suitable admissible functions. To illustrate this, the method presented evaluates the dynamic response of a plate example, whose three edges are usual constrains, and the fourth edge connects to a real spring with arbitrary length and stiffness value. [ABSTRACT FROM AUTHOR]

Instability of internal damping due to collet chuck holder for rotating spindle–holder–tool system is investigated using transfer function approach as well as Routh–Hurwitz criteria with complex coefficients. Firstly, modal parameters of system including mass, stiffness, external damping and internal damping are extracted through three types of experimental modal analysis. Then, the effects of interference fits and clamping lengths between holder and tool on internal damping and instability are elaborated using experimental and numerical results, respectively. Finally, the internal damping instability is investigated through eigenvalue analysis and transfer function analysis in detail. The critical internal damping and phase “Jump” speed are derived. The former can be used to identify the instability mode (forward or backward modes), and latter can be applied to judge in advance whether the instability occurs. These results can be used to design and optimize the novel spindle, holder, and tool system with high damping in high rotating speed milling or deep-hole drilling process. [ABSTRACT FROM AUTHOR]

The existing surface roughness theoretical predictive models exhibit high parameter sensitivity and complexity, resulting in low reliability. Moreover, machine learning-based predictive models are constrained by the training parameter range, limiting their precision and generalization. In response to these limitations and from the frequency domain perspective, this paper proposes an innovative surface roughness (Ra) predictive model for silicon nitride ceramics grinding based on the dynamic grinding force model. First, a dynamic grinding force model was established using single grain scratch test results from both ductile and brittle removal stages, with model parameter estimation assisted by Genetic Algorithm. The results demonstrated a Mean Relative Error (MRE) of 19.51% between experimental and theoretical dynamic grinding force values, and a Relative Error (RE) of 9.37% for average grinding force. Subsequently, the frequency domain characteristics of both experimental grinding force signals and surface topography texture curves were extracted, which exhibited a significant correlation based on cosine similarity and Kendall's tau. Finally, leveraging the frequency domain characteristics of grinding force, the surface roughness predictive model was developed through the Convolutional Neural Network. The predictive model achieved an MRE of 12.79%, with random grinding experiments further confirming the model's accuracy with an MRE of 13.65%. These findings indicate that the proposed surface roughness predictive model offers high generalization capability and accurate prediction across a broader parameter range. [ABSTRACT FROM AUTHOR]

• Clarifying grain-scale material removal mechanisms in micro-cutting processes. • Analyzing grain orientation effects on the primary slip system and machinability. • Discussing grain boundary effects through crystallographic and orientation features. • Revealing grain size effects via the number of grains and boundaries in affected zone. Crystalline material miniature parts are highly required under the development trend of miniaturization in some fields, and micro-cutting is a promising technology to manufacture complex-shaped crystalline material miniature parts. In the micro-cutting process of crystalline materials, the cutter edge radius, cutting parameters and grain size are in the same order of magnitude, and the workpiece has significant microstructure heterogeneity and mechanical property anisotropy. Therefore, the "cutter edge size effect" and "microstructure effect" occur during the micro-cutting process of crystalline materials, which make it difficult to predict the material deformation behavior and machinability, leading to low efficiency and poor accuracy in the manufacturing process of crystalline material miniature parts, and seriously restricting their widespread application. Taking Inconel-718 as the example, the influence of grain orientation, grain boundary and grain size on the micro-cutting machinability of crystalline materials are comprehensively investigated through single-crystal, bi-crystal and polycrystalline orthogonal micro-cutting simulations. Results show that, grain orientation affects the slip system and slip degree during micro-cutting processes, which leads to different material deformation behaviors. The influence of grain boundary on material behaviors in micro-cutting processes can be divided into two aspects i.e., the material response across grain boundary introduced by its presence and the response difference caused by the difference of grain boundaries. Grain boundary features like grain boundary misorientation angle, grain boundary interface orientation, the number deviation of primary slip systems and the Schmid factor deviation of primary slip systems significantly influence the micro-cutting machinability. Besides, grain size affects the micro-cutting machinability by influencing the number of grains, slip systems and grain boundaries involved in the affected zone. Clarified mechanisms can be used as a credible basis to predict the machinability of crystalline materials in micro-cutting processes, and improve the manufacturing efficiency and quality of crystalline material miniature parts. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A multi-scale modeling method to generate crystal plasticity finite element models of polycrystalline materials considering grain boundary misorientation angle characteristic. • The method comprehensively considers the misorientation angle information of grain boundaries at grain-scale and atomic-scale during modeling. • The generated model is able to accurately describe the elastic–plastic behavior and the coupled transgranular-intergranular fracture behavior of polycrystalline materials. • The method has a good potential for studying the influence mechanism of misorientation angle on mechanical properties of polycrystalline materials. Grain boundaries (GBs) are microstructures in polycrystalline materials, which influence the mechanical properties of materials significantly. Simulation is an indispensable means to study GBs due to its high flexibility. However, the existing GB simulation models mostly focus on a single simulation scale, lack the consideration of the grain boundary misorientation angle (GBMA) characteristic and fail to describe the coupled elastic–plastic damage behavior between grains and GBs accurately. To describe the influence mechanism of GB on the mechanical behavior of materials accurately, a GBMA-considered multi-scale modeling method for polycrystalline materials is proposed in this paper. The method is based on molecular dynamics (MD), the crystal plasticity finite element method and the cohesive zone model, which considers the GBMA information at grain and atomic scales comprehensively. Firstly, a GB geometric model containing GBMA characteristic is generated at grain scale through EBSD information. Then the GB cohesive parameters are obtained at the atomic scale by MD simulation. Finally, some experiments are performed for verification, which indicates the high accuracy of the proposed method. Furthermore, three models with the same geometric shape and different grain orientation and GBMA are established to study the influence of GBMA on the mechanical properties of polycrystalline materials. [ABSTRACT FROM AUTHOR]

How to consider the mass loading effects and stiffness modification effects of materials removed on dynamic characteristics in a thin-walled component milling process is an essential problem. Sherman–Morrison–Woodbury formula can be employed and extended to estimate the corrected frequency response function (FRFs) without the material removing effect. In the paper, a novel method, named as structural dynamic modification method with equal mass, to predict the dynamic stable lobe diagram (DSLD) of the thin-walled workpiece milling process is proposed. The whole cutting process is divided into multi-cutting steps with equal length. The presented method is to regard material removal of each cutting step as a modification (or reanalysis) of structure so as to estimate the corrected FRFs based on the so-called Sherman–Morrison–Woodbury formula. The input data of the method is only two sets of the dynamic characteristics of original (unmachined) and finial (machined) structures, which can be easily obtained using experimental modal analysis (EMA) or finite element method (FEM). The accuracy of the method is dependent of the number of cutting step. FEM is highly recommended, and EMA mainly enables the damping ratio of FEM model to be readjusted. The efficiency is higher than one of the methods reported in literatures because it is not necessary to re-build and re-mesh FEM model each time, and the modal analysis can be implemented automatically through pre-programs. Meanwhile, using Sherman–Morrison–Woodbury formula at active coordinates only can greatly improve computational efficiency. Additionally, the probability of singularity occurring is very low comparing with that in the existing methods. Once the dynamic characteristics changing with respect to tool positions are identified, a specific DSLD can then be predicted by using these characteristics along the machining direction. And the cutting parameters for thin-walled components milling can be also optimized to avoid chatter vibration and improve the chatter-free material removal rate and surface finish. Finally, the results are verified by dynamic and milling tests with thin-walled workpiece. [ABSTRACT FROM AUTHOR]

[Display omitted] • Single ellipsoid was ultilized to fit gas and keyhole pores, while multiple connective ellipsoids were used for LOF pores. • Single-pore-included single-crystal simulations with diversiform pores were carried out to evaluate pore effects. • Overall pore effects were divided into three parts i.e., single-ellipsoidal effects, sub-pore quantity effects and sub-pore intersection effects. • Single-crystal mechanical and damage property prediction models for Inconel-718 grains with an internal pore defect were developed. Pore defects inescapably occur during the selective laser melting (SLM) process of metallic materials, which are difficult to be eliminated even by advanced process optimizing and post-treatment technologies. Properties of SLM-fabricated materials depend on the influence of pores, while the effect mechanism is not clearly understood. To clarify the pore effects and achieve reliable forecasting, a statistical-theory-based grain-scale simulation work was performed. Taking Inconel-718 as the example, actual pore defects were detected and classified into three types i.e., gas pore, keyhole pore and lack-of-fusion (LOF) pore, which were then fitted by single or multiple ellipsoids. The volume, shape and posture of pores were characterized by independent parameters, and single-pore-included single-crystal simulations were carried out. Furthermore, overall pore effects were divided into single-ellipsoidal effects, sub-pore quantity effects and sub-pore intersection effects, and the influence mechanisms of pore characteristics on the mean tensile strength and the maximum damage driving force were clarified through partial correlation analysis. Eventually, single-crystal mechanical and damage property prediction models for the grain with an internal pore defect were developed and verified, which show good accuracy with 8–22% relative deviation for damage resistance predictions, and show excellent accuracy with lower than 0.3% relative deviation for strength property predictions. [ABSTRACT FROM AUTHOR]

Abstract: Considering the self-excited and forced vibrations in peripheral milling processes, a novel optimization method of cutting parameters is presented. The optimization method proposed, which is based on the vibration frequency analysis during milling processes, can achieve the most stable cutting process in relative stable region (or conditional stable region). First, relationships between vibration frequencies and phase angle of tooth of cutter in milling processes are investigated. Four kinds of spindle speeds associated with several bifurcations and vibrations are defined. Second, chatter-free regions are subdivided according to these spindle speeds. It is shown that in the so-called subregion C, cutting parameters can be simultaneously optimized for higher material removal rate (MRR) and higher surface accuracy. Third, optimal control theory is employed to determine the optimal cutting parameters, which can achieve the most stable cutting process in relative stable region. Optimizations of spindle speeds and depth of cut are conducted by using the stability charts and performance contours diagrams. The results show that the optimal cutting parameters can also be obtained in the so-called subregion C. Finally, the numerical results are verified and analyzed through milling experiments. [Copyright &y& Elsevier]

[Display omitted] • A geometry-considered 3D pseudorandom grain-scale modelling method to generate accurate and efficient microstructure-dependent crystal plasticity finite element models. • This method comprehensively considers the necessary actual microstructure information, part geometry and their mutual relations during modelling. • This method has higher accuracy and robustness than the Voronoi random method on macroscopic response and microstructure evolution prediction. • There is a potential for full lifecycle tracking of crystalline material miniature parts with the help of this method. Grain-scale modelling and simulation is of vital importance during the full lifecycle of crystalline material miniature parts, whose mechanical responses depend on the actual material microstructure, part geometry and their correlation. Unfortunately, current studies fail to comprehensively consider indispensable microstructure information, and lack the consideration regarding part geometry. Therefore, this paper proposes and implements a geometry-considered 3D pseudorandom grain-scale modelling method, which takes into account the necessary actual microstructure information, part geometry and their mutual relations to generate accurate and efficient microstructure-dependent crystal plasticity finite element (M−CPFE) models. Firstly, the 3D actual grain-scale microstructure was acquired efficiently by combining 2D actual microstructures. Then the geometry-considered grain-scale microstructure was created pseudorandomly based on the actual 3D grain size, orientation and misorientation distributions. On this basis, the M−CPFE model was constructed accurately. The proposed method has been proved to have higher accuracy and robustness than the Voronoi random method on macroscopic response prediction, microstructure generation and microstructure evolution prediction. Furthermore, the applicability in micro-manufacturing and service has been demonstrated by micro sheet bending and micro impeller rotation simulations. There is a great potential for the full lifecycle tracking of crystalline material miniature parts with the help of the proposed method. [ABSTRACT FROM AUTHOR]

[Display omitted] • We investigate the interaction of solute atmosphere with a void in a elastic solid. • The rationality of modeling a solute atom as a point dilatation to obtain the image stress fields. • The elastic fields due to a point dilatation in a elastic solid containing a void are obtained. • Three-dimensional Monte Carlo simulation of solute atmosphere. • The effects of initial solute distribution and temperature on solute atmosphere are studied. The distribution of solute atoms around defects is a hot research topic in the solid theory with long-term importance. In the present work, the interaction of solute atmosphere with a spherical void in a spherical elastic solid is studied based on the elastic and statistical mechanics description of solute atmosphere. The rationality of further modeling a solute atom as a point dilatation to obtain the image stress fields is demonstrated. Based on this point dilatation model, a three-dimensional boundary value problem in the framework of elasticity is formulated and solved. The displacement, strain and stress fields due to a point dilatation in a spherical elastic solid containing a spherical void are derived. The statistical mechanics framework is extended to the three-dimensional case of solute atmosphere. Configurational forces on both the solute atoms and spherical void are defined through the gradient of enthalpy and the well-established surface-independent integrals, respectively. Based on the elastic and statistical description of solute atmosphere, Monte Carlo (MC) method is employed to investigate the effects of initial solute distribution and temperature on the solute atom distribution. Carrying out a great number of MC simulations in a wide range of temperature with different total numbers of solute atoms, a metastable equilibrium state is found, which results from the synergistic effects of low temperature and initial solute distribution. It is shown that there are three stages of variations of the enthalpy with the temperature, from which two transition temperatures have been identified. [ABSTRACT FROM AUTHOR]

Machining of titanium is considered as a challenging process due to its ability to interact with various tool materials when critical cutting temperature is exceeded, resulting in excessive tool wear and poor surface finish, etc. To exhibit an efficient machining process, this research study has experimentally investigated the key quality indicators of machinability, namely surface roughness, cutting temperature, tool wear, in-depth analysis of worn tool and cutting force in the machining process of α-β titanium alloy, which used in critical applications, under three sustainable cooling environments i.e., dry, liquid nitrogen (LN 2) and carbon dioxide (CO 2). The effect of cutting speed and feed rate on such performance measures were examined under a function of cooling strategy as the best substitute in machining. As a result, the feasibility of LN 2 cooling has been confirmed to be more significant for the machining of α-β titanium alloy when compared to dry and CO 2 machining strategies. To sum up, cryogenic cooling (LN 2 cooling) assisted machining of α-β titanium has acquiesced as a sustainable strategy in the context of environmental consciousness. • Turning of Ti6Al4V alloy under various sustainable conditions was investigated. • Tool wear, surface roughness, cutting force and temperature was evaluated. • Worn tools were analyzed in depth with SEM and EDS tools. • LN 2 and CO 2 cooling contributed significantly to improving machining performance. [ABSTRACT FROM AUTHOR]