Finishing Process Research Articles

The use of Preston equation to determine material removal during lap-grinding with electroplated CBN tools

Grinding executed in a lapping configuration is an alternative finishing process benefiting from both grinding and free-abrasive machining, while minimizing the heat effect impact. Electroplated tools can be effectively used in different abrasive processes, including high-speed grinding, however, the assessment of machining performance over time is a key factor in their correct use to achieve satisfactory technological results. In conventional grinding, bigger grain-coverage provides better results due to the higher bonding strength of grains. In lap-grinding, fracturing and crushing of the abrasive particles initially covered by the plating result in a suspension which is typically dosed continuously in free-abrasive machining. Due to this, the process transforms from two-body (grinding) to three-body abrasion (free abrasive machining) which may result in reduced grinding performance approaching asymptotically a specific value while improving surface finish. The main aim of the presented study is the evaluation of electroplated CBN tools used in lap-grinding of 40H alloy steel workpieces whose hardness was 54 HRC. The obtained results and observations of the working surface of CBN wheels and workpieces allowed for the identification of the wear characteristics for three nickel plating thicknesses corresponding to 35%, 50% and 65% of the nominal CBN crystal size and for specific process parameters. The surface roughness Ra parameter decreased gradually from the initial value 1.9 μm to the values below 0.7 μm for bigger B107 grains and for all plating thicknesses. For smaller B64 grains, the surface roughness and waviness parameters reached similar values to those obtained for the larger B107 grains at corresponding processing times. The lowest value of Ra parameter below 0.4 μm was obtained for B64 grains and for the thinnest plating but with a 50% reduction in material removal comparing to B107 grains. The Preston equation was employed to calculate the material removal as a function of time under variable process conditions in the machining zone due to the tool wear. This attempt extended the range of the material removal modeling, despite the fact that the electroplated wheels were subject to wearing down resulting in the gradual reduction in the efficiency, as well as in the change of the working conditions in the workpiece-tool contact zone.

A novel water film enhanced electrostatic agglomeration process to remove fine particles: performance and mechanism

Wet electrostatic agglomeration (WEA) is a very promising method in fine particle removal, however, it is still a challenging problem to avoid short-circuiting of the equipment caused by spraying water during traditional WEA. In this work, a novel WEA process based on a water film was established for the first time, and the fine particle removal and process mechanism were investigated. The influence of discharge and ground electrodes on the particle agglomeration performance was studied, indicating that a much better agglomeration performance was obtained by the spike plate (discharge electrode) thanks to the stronger electric field covering the entire agglomeration area. The corrosion-resistant and low-priced polyvinyl chloride (PVC) plate could significantly improve the water distribution effect after surface grooving modification, and its agglomeration as a grounding electrode under wet conditions was comparable to that of the wet metal plate. The mechanism of the water film enhanced WEA process lay in the fact that the high-voltage electric field greatly promotes the evaporation of the water film, which increased the humidity in the agglomeration space, resulting in liquid bridge force between the water-absorbing particles. In summary, this work provides an alternative novel idea for enhancing the agglomeration performance of the traditional WEA process.

Research of the Ball Burnishing Impact over Cold-Rolled Sheets of AISI 304 Steel Fatigue Life Considering Their Anisotropy.

The present work focusses on the research of the plastic deformation accumulated effect obtained after two different plastic deformation treatments, over the fatigue life of AISI 304 austenitic stainless steel. The research is focused on ball burnishing as a finishing process to form specific, so-called "regular micro-reliefs" (RMRs) on a pre-rolled stainless-steel sheet. RMRs are formed using a CNC (Computerized Numerically Controlled) milling machine and toolpaths with the shortest unfolded length, generated by an improved algorithm, based on the Euclidean Distance calculation. The effect of the predominant tool trajectory direction during the ball burnishing process (which can be coinciding or transverse with the rolling direction), the magnitude of applied deforming force, and feed-rate is subjected to evaluation using Bayesian rule analyses of experimentally obtained results for the fatigue life of AISI 304 steel. The obtained results give us reason to conclude that the fatigue life of researched steel is increased when directions of pre-rolled plastic deformation and the tool movement during ball burnishing are coincident. It also been found that the magnitude of deforming force has a stronger impact over the fatigue life, than the feed-rate of the ball tool.

Data-driven indirect punch wear monitoring in sheet-metal stamping processes

The wear state of the punch in sheet-metal stamping processes cannot be directly observed, necessitating the use of indirect methods to infer its condition. Past research approaches utilized a plethora of machine learning models to infer the punch wear state from suitable process signals, but have been limited by the lack of industrial-grade process setups and sample sizes as well as their insufficient interpretability. This work seeks to address these limitations by proposing the sheared surface of the scrap web as a proxy for the punch wear and modeling its quality from acoustic emission signals. The experimental work was carried out in an industrial-grade fine blanking process setting. Evaluation of the model performances suggests that the utilized regression models are capable of modeling the relationship between acoustic emission signal features and sheared surface quality of the scrap webs. Subsequent model inference suggests adhesive wear on the punch as a root cause for the sheared surface impairment of the scrap webs. This work represents the most extensive modeling effort on indirect punch wear monitoring in sheet-metal stamping both from a model prediction and model inference perspective known to the authors.

Numerical simulation and experimental study of normal force and particle speed in the robotic stream finishing process

Normal force and particle speed are the two most important parameters in determining the mass removal rate on the workpiece in the stream finishing process. However, quantifying them is still a big challenge due to the complexity of the interaction between media flow and the workpiece. In this study, a continuum-based (μ(I) rheology) numerical model was developed to simulate the granular media flow in a robotic stream finishing (RSF) system and validated with in-house experimental data. A novel frictional wall-slip model was developed to describe the media flow speed on the surface of a rectangular workpiece. The impact of three key process variables: (i) immersion depth (D), (ii) angle of attack (θ), and (iii) radial distance (r) on the resulting normal force and media flow speed was analyzed. The resulting normal force on the workpiece strongly depends on the immersion depth. A small increase in the hydrostatic pressure is amplified through elevated effective viscosity near the workpiece, resulting in a significant increase in the normal force. A critical θ for the dependency of normal force was identified. Below the critical θ, the normal force varies slightly with the increase in θ. Above the critical θ, the normal force decreases rapidly with the increase in θ. The normal force also increases linearly with the increase in radial distance. In general, the media flow speed increases rapidly with θ. However, the increase peaks at θ = 75° due to the wake effect behind the leading edge. As D increases, the media flow speed only changes marginally, given the same θ. The media flow speed increases with radial distance, and the relationship is quadratic. We have validated – through experiments – that the numerical model can reliably predict both normal force and media flow speed on the rectangular workpiece. As the local material removal rate has a direct correlation to the normal force and the media flow speed, this numerical model is capable of predicting material removal distribution on an actual polished component and, therefore, will be an indispensable tool for conducting in-process optimization and toolpath planning.

Ultrathick Boron Carbide Coatings for Nuclear Fusion Targets

Boron carbide is an attractive ablator for next-generation inertial confinement fusion (ICF) targets. Here we describe several aspects of our ongoing systematic studies of the deposition and processing of B4C coatings for ICF targets. We show that residual compressive stress in films can be reduced and the deposition rate increased by N-doping. We also demonstrate successful Si substrate etching and surface polishing and discuss remaining challenges and offer potential solutions to the buildup of particulates in the deposition chamber during prolonged coating runs, control of nodular growth defects, and lateral nonuniformity of film properties for deposition conditions with relatively low target-to-substrate distances.

Characteristics and quantification of fine particle loss in internally unstable sandy gravels induced by seepage flow

For internally unstable sandy gravels, fine sand particles might pass through the constrictions of the coarse gravel particles and flow out of the soil with seepage flow. This phenomenon is referred to as internal erosion, which induces fine particle loss and changes particle size distribution, thereby significantly affecting the soil's hydraulic and mechanical properties. To investigate the characteristics of the fine particle loss process in sandy gravels induced by seepage flow, as well as the corresponding permeability change and skeleton deformation, systematic large-scale internal erosion tests were conducted on two kinds of internally unstable sandy gravels under two hydraulic loading paths (constant and multi-stage hydraulic gradients) and three surcharge pressures (0.5, 1.0 and 2.0 MPa). The initiation and progression of internal erosion under different hydraulic loading paths and stress conditions were summarized. An incremental erosion model, which can describe the fine particle loss process under different hydraulic loading paths and incorporate the effect of surcharge pressure, was established based on the volumetric exchange rate of the deposited fines to the fluidized fines. The model was validated not only with the test results of sandy gravels in this study but also with other test results under various hydraulic and stress conditions to demonstrate its versatility.

29 Impact of Extended Feeding Duration on Trained Panel Analysis of Locally Grown Beef

Abstract The objective of this study was to evaluate the impact of increased finishing weights on trained panel analysis and Warner-Bratzler shear force (WBSF) values of locally grown beef. Angus crossbred steers (n = 48) at an average weight of 340.9 kg were divided among two treatments: short-fed (SF) = 522.7 kg average final weight and long-fed (LF) = 613.6 kg average final weight to simulate a beef direct marketing operation. Cattle were split into two pens (n = 12 calves/treatment in each pen) and each pen had access to four automated feeders, which were filled as needed for ad libitum intake. Body weights were recorded at 28 d intervals throughout the finishing process to determine harvest dates and measure cattle performance. Finished steers were transported to a commercial processing facility. A strip loin was collected from the right side of each carcass approximately 48 hours following harvest. Strip loins were wet aged in the absence of light for 21 d, then cut into 2.54 cm steaks and frozen at -20° C until analysis. Sensory evaluations and WBSF were conducted as outlined by the AMSA Sensory Guidelines to evaluate the traits of juiciness, beef flavor intensity, off-flavor intensity, connective tissue amount, myofibrillar tenderness and overall tenderness. Data were analyzed as a completely randomized design with the fixed effect of final cattle weight and the random effect of panel session. Peak internal temperature was included in the model as a covariate. Statistical differences were determined with α ≤ 0.05 and tendencies were observed between 0.06 to 0.09. No differences were observed between treatment groups for initial or sustained juiciness, myofibrillar tenderness, connective tissue amount or overall tenderness (P ≥ 0.140). Steaks from LF cattle produced lower WBSF scores (P < 0.05) compared with SF cattle. Additionally, steaks from LF cattle produced less off flavors (P = 0.05) than SF cattle. Long fed cattle steaks tended to have a greater beef intensity score (P = 0.08). These results indicate that while LF cattle produce more tender beef with more intense beef flavor and less off-flavors, SF cattle still provide a quality eating experience, with less feed input costs. However, if there are potential processing bottlenecks from reduced processing capacity, long fed cattle will also provide a high-quality eating experience as well.

Sulfur-vacancy engineering of natural molybdenite for enhanced EMW absorption

The fine processing and functional application of natural minerals are crucial for allowing the comprehensive utilization of natural mineral resources. This paper reports the modification of natural molybdenite: S-vacancies are used to promote the attenuation of electromagnetic waves (EMWs) in molybdenite matrix composites, thus improving the EMW absorption performance of molybdenite. First, S-vacancies are constructed on the base plane of molybdenite (MoS(2-x)) via treatment with NaBH4. The generated S-vacancies are found to change the original electronic layout, reduce the energy gap, and increase the probability of charge transfer within molybdenite. Concomitantly, the introduction of S-vacancies increases the number of active sites for interfacial and defecs polarization in molybdenite. MoS(2-x)-1 shows a higher absorption performance, with a minimum reflection loss (RLmin) of − 34.35 dB (the absorbing layer thickness is 2.1 mm). The attenuation of EMWs by MoS(2-x) is attributed to a dielectric loss mechanism in which the polarization loss is dominant, and the increase in internal charge transfer promotes conductive loss. The findings of this study greatly expand the application scope of pure natural molybdenite and will facilitate the industrial production of high-performance EMW-absorbing materials and improve the comprehensive utilization of mineral resources.

Preparation of sepiolite-based hybrid silica sol and its application in polyester/cotton fabric flame retardant finishing

Halogen-free flame-retardant finishing of textiles is of great significance. In this study, a new type of phosphorus-rich organic-inorganic flame-retardant hybrid silica sol was prepared by the ion replacement reaction between natural sepiolite and biomass phytic acid, which was then used as the flame retardant for coating finishing of polyester/cotton (T/C) fabric. The structure and morphology of the hybrid silica sol was investigated. The results indicated that prepared silica sol maintained the fibrous structure of sepiolite, which would be helpful to reduce the damage to the mechanical properties of T/C fabric in the flame-retardant finishing process. The tests on the flame retardancy and mechanical properties of T/C fabrics show that the flame retardancy and mechanical properties of T/C fabrics coated by sepiolite-based silica sol were improved. Compared with raw T/C fabric, the limit oxygen index of the optimal sample increased by 24.8% and the char length decreased by 76%. In addition, the elongation at break at warp direction of the optimal sample was 16.3%, which was about 39.16% higher than that of raw T/C fabric. The hybrid sepiolite-based silica sol has broad application prospect.

Material Removal Rate Prediction Based on Broad Echo State Learning System for Magnetically Driven Internal Finishing

Material removal rate (MRR) modeling is crucial for process and quality control in abrasive finishing processes. In this paper, a novel broad echo state learning system (BESLS) is developed to predict MRR in the magnetically driven internal finishing process based on the force signal. This BESLS model employs reservoirs with echo state properties to replace the enhancement layer nodes of the conventional broad learning system. Three representative BESLS architectures are designed and experiments are conducted to validate the developed models. The effect of feature-fusion approaches on prediction accuracy is investigated. Results demonstrate that the prediction error of MRR is only 6.86% for the proposed BESLS model. The model has one reservoir with variable nodes (BESLS-III) and fuses extracted force features and process parameters as input. It also shows remarkable computational efficiency with a testing time of 0.134 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\rm s$</tex-math></inline-formula> , making it a potential candidate for online process control.

A review on preparation process and tribological performance of coatings for internal combustion engine piston ring

Reducing the energy consumption and exhaust emission, and improving the combustion efficiency of internal combustion engine are important for solving the problems of climate change and environmental pollution. The piston ring-liner system is one of the most serious friction pairs in internal combustion engine, accounting for 26% of the total friction loss. Depositing strengthened coatings on the surface of piston rings is an effective method to reduce the friction coefficient and wear rate. This paper reviews the research progress of several representative technologies for preparing coatings, such as electroplating, physical vapor deposition (PVD), thermal spraying and chemical vapor deposition (CVD), and so on. Various coatings, such as Cr-Al2O3 coating prepared by representative electroplating process, CrN and DLC coatings prepared by physical vapor deposition, and Mo-based and C-based coatings prepared by thermal spraying process, are briefly discussed. Furthermore, the positive and negative aspects of commonly used piston ring coatings are compared, and their development trends are summarized.

826 - Process Development and Manufacturing: AN ASSESSMENT OF THE RISKS, BENEFITS AND COSTS ASSOCIATED WITH CELL EXPANSION AND THE FILL AND FINISH PROCESS FOR CELL AND GENE THERAPY MANUFACTURERS

826 - Process Development and Manufacturing: AN ASSESSMENT OF THE RISKS, BENEFITS AND COSTS ASSOCIATED WITH CELL EXPANSION AND THE FILL AND FINISH PROCESS FOR CELL AND GENE THERAPY MANUFACTURERS

Analysis of Worm Deformation Behavior of GH2132 Superalloy

GH2132 superalloy performances excellent properties, such as the good rupture strength and yield strength below 923K, the fine processing plasticity and the good welding properties. The warm working behavior of GH2132 superalloy at 673 K – 773K is investigated by a thermal simulator in this paper. The results show that the worm working effects at the center of specimen is the most significant compared with other positions. The deformation temperature and strain rate is the key parameters significantly affecting the warm working behavior. The increase of the temperature enhances the recovery softening effect, which reduces the stress and the work hardening effect slightly. The deformation heat is significant with the increasing strain rate, which results in the work hardening behavior does not change markedly. This study provides an important reference for the worm forming of GH2132 superalloy.

DEPENDENCE OF THE YIELD OF WINTER WHEAT (TRITICUM AESTIVUM L.) ON SOIL AND CLIMATIC CONDITIONS AND VARIOUS TILLAGES IN THE ZONE OF LIGHT CHESTNUT SOILS OF THE VOLGA-DON INTERFLUVE AREA OF THE SOUTHERN FEDERAL DISTRICT OF THE RUSSIAN FEDERATION

DEPENDENCE OF THE YIELD OF WINTER WHEAT (TRITICUM AESTIVUM L.) ON SOIL AND CLIMATIC CONDITIONS AND VARIOUS TILLAGES IN THE ZONE OF LIGHT CHESTNUT SOILS OF THE VOLGA-DON INTERFLUVE AREA OF THE SOUTHERN FEDERAL DISTRICT OF THE RUSSIAN FEDERATION

Investigation of Process Parameters of a Novel Magnetorheological Finishing Process for External Cylindrical Surfaces

The recent rise in the demand for high precision, close tolerances, and super surface finish quality of components and part assembly modules in the competitive manufacturing industrial environment for the enhanced working life and functional requirements of machines globally. Three revolving curved tip tools based magnetorheological process is designed and developed to fine finish the external cylindrical surfaces of soft and hard materials. The effect of the key operational machining parameters on the surface roughness of a newly developed magnetorheological process was carried out using a one factor at a time method. The magnetizing current, the revolving speed of the tools, the rotational speed of the workpiece, workpiece traverse speed are the parameters that have been considered for this purpose. The experimentation has been performed on the aluminium workpiece because of its broad applicability, such as manufacturing shafts, rods, pistons, and other circular components. The primary purpose of this study was to determine the range of essential control parameters for the newly developed finishing process. The percentage reduction in Ra, Rq, and Rz values are 69.64%, 58.21%, and 54.48%, respectively, after 60 minutes of finishing at magnetizing current 2A, the revolving speed of the tools 30 RPM, the rotation speed of the workpiece 600 RPM and feed 10 cm/min.

Manufacturability study in laser powder bed fusion of biomedical Ti alloys for orthopedic implants: an investigation of mechanical properties, process-induced porosity and surface roughness

PurposeSince the biomedical implants with an improved compressive strength, near bone elastic modulus, controlled porosity, and sufficient surface roughness, can assist in long term implantation. Therefore, the fine process tuning plays its crucial role to develop optimal settings to achieve these desired properties. This paper aims to find applications for fine process tuning in laser powder bed fusion of biomedical Ti alloys for load-bearing implants.Design/methodology/approachIn this work, the parametric porosity simulations were initially performed to simulate the process-induced porosity for selective laser-melted Ti6Al4V as per full factorial design. Continually, the experiments were performed to validate the simulation results and perform multiresponse optimization to fine-tune the processing parameters. Three levels of each control variable, namely, laser power – Pl (180, 190, 200) W, scanning speed – Vs (1500, 1600, 1700) mm/s and scan orientation – ϴ{1(0,0), 2(0,67°), 3(0,90°)} were used to investigate the processing performance. The measured properties from this study include compressive yield strength, elastic modulus, process-induced porosity and surface roughness. Finally, confirmatory experiments and comparisons with the already published works were also performed to validate the research results.FindingsThe results of porosity parametric simulation and experiments in selective laser melting of Ti6Al4V were found close to each other with overall porosity (less than 10%). The fine process tuning was resulted in optimal settings [Pl (200 W), Vs (1500 mm/s), ϴ (0,90°)], [Pl (200 W), Vs (1500 mm/s), ϴ (0,67°)], [Pl (200 W), Vs (1500 mm/s), ϴ (0,0)] and [Pl (200 W), Vs (1500 mm/s), ϴ (0,0)] with higher compressive strength (672.78 MPa), near cortical bone elastic modulus (12.932 GPa), process-induced porosity (0.751%) and minimum surface roughness (2.72 µm). The morphology of the selective laser melted (SLMed) surface indicated that the lack of fusion pores was prominent because of low laser energy density among the laser and powder bed. Confirmatory experimentation revealed that an overall percent improvement of around 15% was found between predicted and the experimental values.Originality/valueSince no significant works are available on the collaborative optimization and fine process tuning in laser powder bed fusion of biomedical Ti alloys for different load bearing implants. Therefore, this work involves the comprehensive investigation and multi-objective optimization to determine optimal parametric settings for better mechanical and physical properties. Another novel aspect is the parametric porosity simulation using Ansys Additive to assist in process parameters and their levels selection. As a result, selective laser melted Ti alloys at optimal settings may help in examining the possibility for manufacturing metallic implants for load-bearing applications.

Fundamental and Development of Microreaction Technology for the Application of Fine Chemicals Synthesis

The fine chemical process has many environmental and safety problems related to the unavoidable use of various organic reactions which are highly involved with exothermic reactions, explosive intermediates, corrosive reagents, toxic or reactive gases, flammable and pyrophoric compounds, and extreme conditions. Limited by the traditional batch process, the efficiency of these reactions should be manually lowered to keep the reaction from going out of control. Benefiting from its rapid transfer of reaction heat, efficient micro-mixing of ingredients, and minimal hold-up of hazardous reagents, continuous-flow microreaction synthesis has emerged as a new technology for producing fine chemicals efficiently and safely in the last two decades. Here, we will introduce some recent progress on the fundamentals and developments of efficient, green, and safe processes for fine chemical synthesis using microreaction technology mainly by our group, including rearrangement reaction, cycloaddition reaction, diazotization reaction, coupling reaction, alkylation reaction, and sulfonation reaction. Based on our research progress, the development of microreaction technology in fine chemical synthesis was discussed here, including applying online analysis and intelligent algorithms to improve the efficiency of the development of microreaction systems from lab scale to commercial production, extending the application of microreaction technology to solid or particle treatment, studying the behaviors of heterogeneous reactions, revealing principles for scaling up heterogeneous reactions in specialized microreactors, and decision toolbox considering both the characteristic of the microreaction system and the overall goal of the industry.

Fabrication and characterization of patterned leather-like biomaterial derived from Brazilein/Glycerol-finished Bacterial Cellulose by using 3-in-1 textile finishing process

Fabrication and characterization of patterned leather-like biomaterial derived from Brazilein/Glycerol-finished Bacterial Cellulose by using 3-in-1 textile finishing process

Enabling rotary atomic layer deposition for optical applications.

Atomic layer deposition (ALD) has been proven as an excellent method for depositing high-quality optical coatings due to its outstanding film quality and precise process control. Unfortunately, batch ALD requires time-consuming purge steps, which leads to low deposition rates and highly time-intensive processes for complex multilayer coatings. Recently, rotary ALD has been proposed for optical applications. In this, to the best of our knowledge, novel concept, each process step takes place in a separate part of the reactor divided by pressure and nitrogen curtains. To be coated, substrates are rotated through these zones. During each rotation, an ALD cycle is completed, and the deposition rate depends primarily on the rotation speed. In this work, the performance of a novel rotary ALD coating tool for optical applications is investigated and characterized with S i O 2 and T a 2 O 5 layers. Low absorption levels of <3.1p p m and <6.0p p m are demonstrated at 1064nm for around 186.2nm thick single layers of T a 2 O 5 and 1032nm S i O 2, respectively. Growth rates up to 0.18nm/s on fused silica substrates were achieved. Furthermore, excellent non-uniformity is also demonstrated, with values reaching as low as ±0.53% and ±1.07% over an area of 135×60m m for T a 2 O 5 and S i O 2, respectively.