Final Workpiece Research Articles

Choosing the Design of a Radial-Shear Rolling Mill for Obtaining a Screw Profile

The purpose of this work is a comparative analysis of the workpiece shape, and parameters of the stress-strain state during deformation on two radial-shear rolling mills with different roll configurations to determine the most suitable scheme for obtaining a screw reinforcement profile. During the FEM simulation of the radial-shear rolling process in the DEFORM program, a comparison of the workpiece shape change after rolling, equivalent strain, damage index, and Lode–Nadai index was carried out. Steel 10 (analogue of AISI 1010) was chosen as material workpiece. The analysis of the obtained data revealed that the most rational choice for the implementation of the reinforcement profile production process is the radial-shear rolling mill RSR 10-30. Subsequent modeling of the combined process of radial-shear rolling and twisting in a screw matrix showed that when using rolls of RSR 10-30 mill, the screw profile of the workpiece is formed successfully, whereas using rolls of the SVP-08 mill, the formation of a screw profile is impossible due to jamming due to an irregular cross-section shape. A laboratory experiment confirmed the possibility of forming a screw reinforcement profile at RSR 10-30 mill, and an assessment of the geometric parameters of the final workpiece showed full compliance with the dimensions of the profiles obtained during modeling and experiment.

Experimental investigation of nanofluid lubrication on surface roughness under MQL aluminum alloy 6061-T6 series in drilling

PurposeThis study aims to investigate the impact of varying the number of minimum quantity lubrication (MQL) nozzles, wind pressure, spindle speed and type of lubrication on surface roughness, fatigue life and tool wear in the drilling of aluminum alloy 6061-T6.Design/methodology/approachThe effect of using different lubricants such as palm oil, graphene/water nanofluid and SiO2/water in the MQL method was compared with flood and dry methods. The lubricant flow and feed rate were kept constant throughout the drilling, while the number of nozzles, wind pressure and spindle speed varied. After preparing the parts, surface roughness, fatigue life and tool wear were measured, and the results were analyzed by ANOVA.FindingsThe results showed that using MQL with four nozzles and graphene/water nanofluid reduced surface roughness by 60%, followed by SiO2 nanofluid at 56%, and then by palm oil at 50%. Increasing the spindle speed in MQL mode with four nozzles using graphene nanofluid decreased surface roughness by 52% and improved fatigue life by 34% compared to the dry mode. SEM results showed that tool wear and deformation rates significantly decreased. Increasing the number of nozzles caused the fluid particles to penetrate the cutting area, resulting in improved tool cooling with lubrication in all directions.Originality/valueNumerous attempts have been made worldwide to eliminate industrial lubricants due to environmental pollution. In this research, using nanofluid with wind pressure in MQL reduces environmental impacts and production costs while improving the quality of the final workpiece more than flood and dry methods.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2024-0021/

Experimental study on abrasive flow finishing of narrow inner cavity of alumina-dispersed copper absorber

Given the difficulties in processing and detecting the narrow and deep inner cavities of the diffusive copper absorber used by the High Energy Photon Source (HEPS), a regression equation prediction model for surface roughness and material removal depth based on abrasive flow machining was proposed through mixed-level orthogonal experiments. The influences of machining area pressure, machining cycle number, and abrasive mesh number on surface roughness and material removal were revealed. Subsequently, abrasive flow machining verification experiments were conducted on the narrow and deep inner cavities of the absorber, showing that the experimental results were within 15% error compared to the model predictions. After abrasive flow machining, the roughness decreased from about 4.4 μm to around 0.6 μm, significantly improving the surface quality of the workpiece. These research findings can provide a theoretical basis and technical support for the optical finishing of workpieces with narrow and deep variable cross-section inner cavities.

Evaluation of Suitability of High-Speed Drag Finishing Machine Prototype Utilization for Workpiece Modification

The purpose of the experimental results evaluated in this paper is to verify the viability of using a prototype drag finishing machine for the modification of machined workpieces. The workpieces used in the experiments had a cylindrical shape and were manufactured by turning. Three different workpiece materials were tested, and three workpieces for each material were machined with different cutting parameters. Multiple aspects of the drag-finishing process influence were kept track of—surface roughness, dimensional accuracy, and edge burr shape change. The parameters of the drag finishing were kept constant for all workpieces, and the development of each aforementioned observed aspect was recorded. The workpieces were periodically removed from the process and measured using a coordinate measuring machine with a touch probe, a surface roughness measuring machine, and an optical microscope. Based on the gathered data, it can be concluded that the usage of a prototype drag finishing machine designed primarily for cemented carbide tool microgeometry modification is viable for workpiece finishing as well. The parameters of the drag-finishing process need to be adjusted depending on the workpiece material and initial surface roughness. Additionally, the medium used for the drag finishing should be considered with respect to the desired output quality of the workpiece. Experimental work shows that having one multi-purpose machine for precise modification of wide range of materials and shapes can be an effective approach from the standpoint of economy and productivity when it comes to small numbers of workpieces requiring surface finishing.

Predictive Temperature Control of an Industrial Heating Process

This paper presents an approach to control the temperature of an industrial heating process where a workpiece is transported through a heating unit in order to reach a certain temperature. To control this process is challenging due to the variable and possibly abruptly changing feed rate while requiring the final workpiece temperature to be maintained at a constant value. The speed itself cannot be influenced by the control system. However, its future trajectory is known to a certain extent at runtime. A model predictive controller is presented, which is characterized by the fact that the prediction horizon is dynamically adjusted to the transportation speed, that the traveled distance of the workpiece within the horizon is constant. Moreover, the step size of the integrator is also adapted, yielding a constant number of integration steps despite large variations in velocity. Because of the special structure of the used model, the system state cannot be reused from one time step to the next and needs to be reconstructed in a receeding horizon fashion, even if the model was perfect. This is also a distinctive feature of the presented control scheme. Simulation and measurement results are provided, showing that the presented controller achieves promising results and outperforms the existing lookup-table-based controller currently in use.

Cutting Performance and Wear Behavior of Self‐Developed Silicon Nitride Ceramic End Mills with Optimized Structure for High‐Speed Machining of GH4099

Ceramic tool materials possess a wide range of potential in machining nickel‐based superalloys due to their superior wear resistance, high‐temperature hardness, and strong chemical stability. Herein, a structural optimization scheme of self‐developed silicon nitride ceramic end mill based on stiffness enhancement and performance improvement is proposed, and the key geometric angular parameters scope of the self‐developed ceramic end mills are prioritized via the finite‐element simulation method. Through precision grinding manufacturing and sandblasting pretreatment, the cutting performance and tool wear behavior of three optimized self‐developed silicon nitride ceramic end mills (called S4‐1, S4‐2, S4‐3 respectively) are comprehensively analyzed in comparison, including cutting force, milling temperature, surface quality, and tool life. The results indicate that the cutting force and cutting temperature of all the optimized ceramic end mills are effectively restrained compared with the nonoptimized ceramic tool(S4), and the final workpiece surface roughness is significantly reduced. Further, better surface quality can be obtained by optimized ceramic mills. In terms of tool life, ceramic end mill with optimized construction in best can be increased by up to 1.9 times. The wear mechanism and pattern of the three optimized ceramic milling tools are similar, which is adhesive wear, diffusion wear, and notch wear. Overall, the effectiveness of the optimization scheme for ceramic end mill is successfully verified.

Chemical assisted ball end magnetorheological finishing of aluminium 7075 alloy

Areas like aerospace, solar, medical, electronics, optics widely use nano-finished or high precision aluminium alloys. These nano-finished aluminium alloys are being used as metal mirrors, micro-electronics devices, diaphragm in optical sensors etc. In general, aluminium alloys are finished by conventional processes such as grinding, lapping. However, to achieve nano-level finish on soft material like aluminium alloys which possess high malleability and ductility is difficult for traditional processes without producing high residual stresses, subsurface damage etc. In this work, the surface finish of aluminium 7075 alloy workpiece was improved using a novel finishing technique viz. chemical assisted ball end magnetorheological finishing (CA-BEMRF). To validate the results a comparison of % decrease in surface roughness obtained after ball end magnetorheological finishing (BEMRF) as well as achieved after CA-BEMRF process is carried out. Results showed a 1.84 % improvement in % decrease in surface roughness after CA-BEMRF process as compared to BEMRF without chemical assistance. The statistical and graphical effects of various changing process parameters on % decrease in surface roughness are addressed. Using analysis of variance (ANOVA) and the F-test, significant process factors impacting surface roughness during workpiece finishing are identified. Optimum value of % decrease in surface roughness has been found as 55.316 at magnetizing current 3.43amp, tool rotational speed 326.97 rpm and working gap of 0.74 mm. Confirmatory experimental tests have been conducted and results obtained were found very close to the predicted outcome. Scanning electron microscopy (SEM) of the workpiece finished using BEMRF process and CA-BEMRF technique are compared to assess the effects of magnetizing current, tool rotation and working gap on surface topography of machined surface.

An Image Stitching Scheme Based on Cameras Coordinate Transformation and Template Matching

In the detection of a large-size longitudinal beam workpiece, it is impossible to obtain the complete picture of the workpiece only by relying on a single camera, so it is necessary to realize the position movement of the camera with the help of a motor to obtain image data one by one, in which image stitching is the key to realize this technology. Based on this, this paper proposes an image stitching scheme based on the camera’s coordinate transformation and template matching. The scheme first uses a motor to drive three cameras to the image acquisition and then uses the coordinate transformation between cameras to obtain the stitched image of the area. After cameras are moved to the next image acquisition area, the image stitching algorithm based on template matching is used to complete the image stitching of the two areas. The above steps are repeated until the cameras complete the image acquisition task of all areas and the image stitching of the final workpiece is completed. Through the experimental verification, the proposed template matching scheme for the approximate overlapping areas between images can effectively improve the efficiency of image stitching, and the specific improvement effect in this experiment can reach 46.2%, and the overall image stitching scheme meets the requirements of detection efficiency.

Modeling of the Variation Propagation for Complex-Shaped Workpieces in Multi-Stage Machining Processes

Variation prediction and quality control for complex-shaped workpieces in automotive and aerospace fields with multi-stage machining processes have drawn significant attention because of the widespread application and increasing diversity of these kinds of workpieces. To finish the final workpieces with complex shapes, multiple setups and operations are often applied in machining processes. However, sources of geometric error, such as fixture error, datum error, machine tool path error, and the dimensional quality of the product, interact complicatedly at different stages. These complex interactions pose significant challenges to final product error prediction and reduction. Manufacturing error prediction based on stream of variation is an effective way to control the machining quality. However, there are few integrated models that can describe the interactions among types of geometric error sources from different stages for different kinds of complex workpieces. This paper proposes a modified error prediction model to systematically capture the interactions of different error sources among different operations for complex-shaped workpieces in multi-stage machining processes. Using differential motion vectors, the connection of all key variations from machine, fixture, and workpiece is established. This modified model can not only handle general fixture layouts for complex workpieces, but also introduce machining-induced variations. Based on this model, the main error sources identification method and error compensation method are proposed. In order to evaluate the effectiveness of the proposed method, engine blocks are used to be machined as an example. Compared with a machining process without a compensating strategy, the average machining error of the key feature is reduced by 80.5% after compensating for the main error sources.

Effectiveness of synthetic coolant at 0°C on machining of SS304 with PVD coated TiCN tool to evaluate and compare tool wear and surface finish with conventional machining method

ABSTRACT The work-hardening and low thermal conductivity characteristics of SS304 had always been a challenge to machine it easily with better tool life and surface finish. The type of coolant, its temperature and surface coated inserts plays a pivotal role in machining the hard materials. A number of experiments were performed with a TiCN and tungsten carbide inserts in combination with soluble/synthetic coolant at ambient temperature and at 0oC TiCN-coated cemented carbide insert with synthetic coolant at 0°C is recommended for machining as per the results obtained through this research work. It was found that TiCN-coated inserts used for machining SS304 with synthetic coolant at 0°C provide better tool life, less tool wear, improved surface finish and low heat generation. The tool life was enhanced approximately by 75%, 20% reduction in maximum temperature generation and 50% improvement in surface finish of workpiece.

Development of MR fluid assisted novel vibration damping fixture for milling machine

Chatter occurs in all metal cutting process and it is an important factor that causes uneven tool wear and reduced tool life resulting in poor surface finish of work piece. It even causes geometrical inconsistencies and poor surface finish. It can lead to higher costs, delayed deliveries and even loss of orders due to poor quality of the machined component. To reduce and control the tool vibration in metal cutting it is necessitating that to develop a clamping method to improve the vibration damping capability and improves the machining conditions. To cater this need design and development of Magnetorheological (MR) fluid assisted novel vibration damping fixture designed. The application of MR damper assisted fixture in milling machine is considered to be a solution for better vibration control and surface finish. From the experimental investigation it was evident that MR damper performance depends on parameters like suspended fluid, density, reaction time, particle size, maximum yield stress. The viscosity of the MR fluid depends on the intensity of magnetic field applied. Coil orientation, number of turns, current, gap between cylinder and piston are important parameters to be consider while designing a MR Damper. From the experimental results it was witnessed that the magnetorheological assisted fixture reduces the vibration during machining significantly and improves the surface roughness and machining performance.

Effect of copper nano-cutting fluids in end milling of al 6061 and its influence on work piece morphology

Due to its exceptional mechanical qualities, aluminium 6061alloy is frequently utilised at automotive and aerospace industries. During the machining process, lubricating oil is typically supplied into the cutting zone to enhance machining performance, including tool life and workpiece surface quality. However, conventional coolants perform less effectiveat higher temperatures. The introduction of Copper Nano coolant at cutting interface could sustain greater temperatures. The surface finish of work piece is improved significantly as the Nano coolants at the tool-chip interface considerably reduces friction and thermal deformation. Utilizing the Minimum Quantity Lubrication (MQL) approach could reduce the amount of lubrication oil needed, reducing pollution. Cu Nano lubricants are made in concentrations of 0.2, 0.6, and 1.0% vol. in a water–oil base lubricant in a 20:1 ratio. The size, structure, and elemental content of the Cu nanoparticles are studied using EDX and FESEM. Cutting force, temperature, and surface quality are alsomeasured. It has been noted that the use of copper Nano coolants enhanced the workpiece's surface polish and greatly decreased the cutting forces and cutting temperatures. The development of thin layer over work piece is responsible for improved surface finish and reduced cutting forces and temperatures.

Influence of the advanced joint path strategies on the energy absorption capacity of Ti-6Al-4V Taylor bar based on additive manufacturing

One of the vital parameters of the additive manufacturing (AM) process is the scanning strategy. In this article, advanced joint path strategies based on irregular hexahedrons instead of conventional regular elements are proposed, and the influences of advanced joint path strategies on the energy absorption capacity of Ti-6Al-4V Taylor bar are investigated. In particular, the thermomechanical results reveal that the zigzag loop path strategy has more influence on deformation than all advanced joint path strategies, among which the zigzag joint path strategy has the maximal effect, and the centrosymmetric joint path strategy has the minimal effect. Meanwhile, through the impact response of the Ti-6Al-4V Taylor bar with AM residual stress (AM RS), the centrosymmetric joint path strategy, which can better uniformly distribute the deformation, can maximize the energy absorption capacity of the structure. HIGHLIGHTS Advanced joint path strategies based on irregular hexahedrons instead of conventional regular elements are proposed. A fully coupled thermomechanical analysis between the AM process and the transient impact problem. Advanced joint path strategies and the generated RS on the impact response of the final workpieces (parts) are studied. A suitable joint path strategy for the generation of a formed part is identified, which allows a maximal energy absorption capacity.

Effect of nano-minimum quantity lubrication on cutting temperature and surface roughness of milling AISI D3 tool steel

Machining is the manufacturing process used to create components that are the right size and shape. For machining processes, numerous cooling methods are employed. Surface finish of workpiece is affected by heat generated at tool workpiece interface because of friction. The machining technologies include conventional cooling, minimum quantity lubrication, cryogenic cooling, and nanofluid cooling. Because of its excellent qualities, AISI D3 is appropriate for creating blanking and shaping tools. It has high strength, good hardenability, and resistance to wear. The major aim of this study is to see how a tiny amount of lubricant combined with TiO2 nanofluids affects the cutting temperature and surface roughness when milling AISI D3 material. The results suggest that using nanoparticles in combination with lubricant reduces cutting temperature and improves surface roughness. Because the cutting fluid's thermal conductivity has increased, adding TiO2 to MQL results in cutting temperatures of 215.6 °C, 207.1 °C, 199.2 °C, and 195.1 °C for 0.3 %, 0.5 %, 0.7 %, and 0.9 % TiO2, respectively. Surface roughness (Ra) values for 0.3 %, 0.5 %, 0.7 %, and 0.9 % TiO2 in MQL are 0.501, 0.498, 0.481, and 0.455, respectively. A 0.9 % TiO2 nanoparticle concentration is believed to be superior for lower cutting temperatures and better surface quality.

Image-Based Precision Measurement Technology for the Quality Inspection of Crane Boom Materials

With the slow rise of the construction industry, cranes, as indispensable mechanical equipment in construction projects, are widely used in the lifting and handling of specific space ranges of construction projects. The quality of crane booms is particularly important for safety. This paper uses image measurement methods including filter processing, mean filtering, and Gaussian filtering to detect the quality of the crane boom material. The image is processed by the wavelet transform and Fourier transform. The grayscale transformation stretching method is applied to the surface image analysis of the boom material to obtain the final inspection. The research results show that the use of image measurement methods can effectively measure the thickness of the crane boom material, the geometric information of the boom material, and the surface roughness of the material and obtain effective image information. The detection accuracy reaches 98.1%. The error can be controlled better. The inspection and research on the quality of crane jib materials can ensure the quality and performance of crane jib materials, reduce the potential safety hazards of cranes during operation, and improve safety. This article organically combines workpiece surface roughness detection with digital image processing technology to preprocess the surface picture of the arm tube material. On this basis, the texture features in the image are extracted and programmed to calculate, and the final workpiece is obtained by the surface roughness value, which proves the feasibility of this method. The research results have very important practical significance for the detection of the quality of the arm tube material and the improvement of the quality level of the arm tube material.

Effect of CNC Interpolator Parameter Settings on Toolpath Precision and Quality in Corner Neighborhoods

Surface quality, machining time, and precision of the final workpiece are key criteria of optimization in CNC machining. These criteria are influenced by multiple factors, such as path interpolation, feed drive system settings, machine dynamics, and the manufacturing process. The properties of the output of the interpolator indirectly influence all subsequent phases of the machining process, thus influencing the quality of the end product. This paper focuses on the effects of interpolator settings on toolpath quality and precision in corner neighborhoods for the commercial Heidenhain iTNC interpolator. A novel method of toolpath quality evaluation suitable for interpolator output toolpaths is proposed, and the effect of multiple CNC parameters on toolpath quality and precision in corner neighborhoods is quantified based on results obtained on a testing toolpath and verified on a toolpath composed of linear segments only. Both toolpath quality and precision were found to depend primarily on the parameters of limit frequency, contour tolerance, and corner jerk settings with precision additionally depending on angle size. The results show that both toolpath quality and precision in corner neighborhoods can be successfully controlled by the corner jerk limit parameter settings. The presented methodology provides a practical guide for CNC parameter settings in Heidenhain interpolators aimed at predicting toolpath quality and precision in corner neighborhoods.

Impact of wire and arc additively manufactured workpiece geometry on the milling process

In recent years, the wire and arc additive manufacturing (WAAM) process has been given attention as a possibility to save material during the production of large-scale parts. Drawbacks of the WAAM process are the relatively low surface quality and the low form accuracies, which require post-processing of all functional surfaces. The milling process is researched as a post-processing option, especially to achieve high form accuracies. While several authors presented successful applications of the milling process, the difficulties of machining wire and arc manufactured parts (WAAM-parts) due to the part geometry have not yet been researched. In the present research, the impact of the WAAM-part geometry on the milling process was analyzed by machining three sets of samples, and guidelines for a milling strategy were developed. The results show that the geometry leads to modulated cutting forces, whose frequency, in turn, has to be considered for the milling setup. Additionally, the modulated cutting force leads to a periodically changing deflection resulting in a form deviation on the final workpiece.

Modeling of the temperature field induced during electrical discharge machining

Electrical discharge machining is a process with main thermal active principal. Thus, for example for steel materials it is unavoidable to modify the rim zone of the final workpiece. Knowledge or even prediction of these modifications would improve industrial applications. Basis for this is the information about the time and locally resolved temperature field, which is not available in that form today. Hence the objective of this work is to establish a model of the temperature field within the electrodes rim zone during electrical discharge machining process. In this work, this field is modeled for the electrical discharge machining process based on the measurable discharge energy of a single discharge. First, an energy dissipation model for a single discharge is presented. In the next step, the interaction of two consecutive discharges is analyzed. Both results are the inputs for a macroscopic process model to calculate the temperature field of the whole workpiece. Finally, by coupling this macroscopic temperature field and the single discharge model it is possible to determine the locally resolved temperature field at any time of the process. For typical conditions, it is very unlikely that two discharges affect each other regarding overlaying temperature fields in the micro range but over time, a macroscopic heating could take place depending on the dielectric cooling efficiency.

Experimental integrated approach for mechanical characteristic optimization of FDM-printed PLA in an energy-saving perspective

This experimental study investigates the effects of process parameters for 3D printing polylactic acid (PLA) samples on both the mechanical properties obtained and the energy consumption in the fused deposition modelling (FDM) process. The explained experimental activities provide an in-depth evaluation of all the strategies adopted in different temperatures and scan speed strategies. The results, extracted in tensile strength, ultrasonic inspection (UT), and specific energy consumption (SEC), highlight the printing parameters that mainly affect the mechanical characteristics of the final workpieces and the energy consumption to find an appropriate energy-saving energy strategy for the PLA additive manufacturing process. The results indicate a more excellent uniformity of the molded material, reducing the printing time and total energy consumption at high speeds (V = 110 mm/s) and one level of temperature (T = 215 °C). A new efficiency index has been introduced to release guidelines to pursue the best setup compromise.

Partially Deacetylated and Fibrillated Shrimp Waste-Derived Chitin as Biopolymer Emulsifier for Green Cutting Fluids-Towards a Cleaner Production.

Up to date, most metalworking fluids (MWFs) are emulsions made of petroleum-derived oil bases and sodium petroleum sulphonate emulsifiers. They are not readily biodegradable, and their waste is hazardous for users and the environment. Therefore, green MWFs are required for achieving cleaner production processes. Recently, various MWFs have been developed using vegetable oil bases to meet biodegradability to some extent. However, the emulsifier has been scarcely replaced by a green product. This research aims to produce and evaluate Pickering emulsions made of Jatropha oil (JO) and partially deacetylated and fibrillated chitin (PDFC) as emulsifiers at different concentrations. JO is a non-edible biodegradable oil with remarkable lubricity properties, while PDFC is produced by extracting chitin from waste heads and shells of the shrimp species Litopenaeus vannameii, followed by partial deacetylation and further fibrillation, which improves wettability and stabilization. The prepared emulsions were characterized in terms of creaming index and size of emulsion droplets and evaluated as MWFs in actual turning operations of AISI 1018 steel bars via minimum quantity lubrication (MQL) technique. The findings suggest PDFC as a potential eco-friendly emulsifier to form green MWFs with acceptable stability generating low cutting forces and significant workpiece finishing and chips quality.