bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of Electroplated CBN End-Mill for High-Efficiency Face Milling of Carbon Fiber Reinforced Plastic
Authors: Furuki Tatsuya , Hirogaki Toshiki , Aoyama Eiichi , Ogawa Keiji , Inaba Kiyofumi
Published: September 2015

Carbon fiber reinforced plastic (CFRP) was developed in the 1960s. Since then, it has been used in various fields. Accordingly, the number of studies related to machining of CFRP has been increasing (e.g. cutting, laser processing, or abrasive water jet machining). However, these studies have been focusing on the trimming of surplus portions or drilling. In addition, the degradation of mechanical properties due to the heat induced during machining has not been sufficiently considered. Furthermore, another issue is the cost involved, such as tool and equipment costs. This makes several of these proposed methods tremendously expensive. Therefore, in this study, electroplated end-mills with electrodeposited cBN or diamond grains of different grit sizes (the mesh size are #600, #1000, #1500 and #2000) are fabricated. As a result, the cost of the electroplated tool will decrease by 2/3 compared to general diamond-coated tools. Moreover, the flat cutting of CFRP is often carried out with these fabricated tools and with general diamond-coated tools. In cases where the fabricated tools are used, the machined CFRP products are burr-free or nap-free. Additionally, the induced CFRP temperature during cutting decreases compared to the case of diamond-coated tools. From these results, the optimum grit size was determined to be #1000. On the other hand, end-mills with deposited cBN or diamond grains, fixed on the tip of the fabricated tool, occasionally dropped out after a few paths. Therefore, efforts are presented to improve the tool tip shape and minimize its grain dropout rate. Based on such improved characteristics, the electrodeposited end-mill is expected to be able to machine CFRP more effectively.
Analysis of HVAC Energy in Automotive Paint Shop
Authors: Feng Lujia , Mears Laine
Published: September 2015

Paint shop is the biggest energy consumer in automotive manufacturing plant. Large amount of conditioned air, which leads to a high energy demand, is one of the basic demands in guaranteeing high quality product and a comfortable working environment. A good design of HVAC system in the paint shop is also crucial in energy conservation. This paper presents thermodynamic simulation models of the HVAC system for both painting booth and building. Key parameter effects of the energy consumption were analyzed; different air flow routes were compared. Finally, optimal operation strategies in terms of energy, cost, and emission were discussed.
The Prediction of Fixture Comprehensive Influence on the Machining Error of Features Pattern
Authors: He Gaiyun , Guo Longzhen , Tian Wenjie , Zhao Xiangsong
Published: September 2015

The position and orientation deviation of workpiece caused by the fixing errors of the fixture influences the machining accuracy of workpiece. This paper presents a method of predicting the fixture induced error and its influence on the machining accuracy of features pattern. Firstly, the mathematical model for predicting fixing error caused by locators and locating surface geometrical errors and caused by clamping force and machining force is formulated. Then, based on the 3-2-1 positioning fixture, the influence of fixing errors on the machining accuracy of features pattern is analyzed after introducing the definition, inspection and evaluation method for the composite position error of features pattern. Finally, taking 4-holes pattern in rectangular distribution as an example, the process of predicting the composite positional error of features pattern is detailed and a simulation experiment is conducted. The results show the rightness and validity of this method.
Laser Profiling of Aluminum Oxide Grinding Wheels
Authors: Lutey Adrian H. A. , Fortunato Alessandro , Carmignato Simone , Zanini Filippo , Ascari Alessandro
Published: September 2015

Laser profiling experiments are performed at normal incidence on fine grain medium density aluminum oxide grinding wheels with a pulsed nanosecond 1064nm fiber laser source with maximum pulse fluence 369J/cm2. In order to determine the incision depth and ideal laser pass separation distance, laser exposures are first performed on high purity, low porosity aluminum oxide blocks and subsequently analyzed with an optical profiler operating in confocal mode. This ablation data is then applied to path planning for grinding wheel profiling experiments, with division of the necessary removal depth according to the measured incision depth and ideal pass separation distance. X-ray computed tomography is utilized to determine the resulting profile accuracy as a function of process parameters. Test results indicate a maximum profile accuracy in the order of 200μm; however, in order to approach the accuracy of diamond dressing, some two orders of magnitude lower, it is likely that tangential laser incidence is necessary.
Function Block-Based Integration Mechanisms for Adaptive and Flexible Cloud Manufacturing
Authors: Wang Xi Vincent , Wang Lihui
Published: September 2015

Cloud Computing is the new enabling technology that offers centralised computing, flexible data storage, and scalable services. In the manufacturing context, it is possible to extend the Cloud technology for integrating and provisioning manufacturing facilities and capabilities in terms of Cloud services. In this paper, a function block-based integration mechanism is developed to integrate various types of manufacturing facilities. A Cloud-based architecture is also deployed to provide a service pool which maintains these facilities in terms of manufacturing services. The proposed framework and mechanisms are evaluated by implementations. In practice, it is possible to establish an integrated manufacturing environment across multiple levels with the support of manufacturing Cloud and function blocks. It provides a flexible architecture as well as adaptive and integration methodologies for the Cloud manufacturing system.
Stochastic Maintenance Opportunity Windows for Serial Production Line
Authors: Zou Jing , Chang Qing , Lei Yong , Xiao Guoxian , Arinez Jorge
Published: September 2015

Timely performance of preventive maintenance (PM) tasks is a critical element of manufacturing systems. The current PM at most manufacturing plants is to conduct maintenance tasks during non-production shifts, breaks, or other scheduled downtime. This practice may introduce unnecessary extra labor and overhead costs. Therefore, there is need to look for hidden maintenance opportunities to perform PM tasks during normal production time without impacting throughput. Additional benefit of the hidden opportunity window is that it can be translated to hidden energy saving opportunity during which machines can be strategically shut down or turned to energy saving mode while PM can be performed. Since production schedules are always made beforehand, the development of opportunity window and the downtime schedule need future prediction about the production system. In this paper, a stochastic model of the downtime opportunity on serial production systems is developed. Based on the stochastic model, revised opportunity window and recovery time is defined, which can help on production control on deciding when and where to insert the downtime events and the duration of the downtime events for the incoming process.
Analysis of Shaped Electrode Based on Size Effects in Electrical Discharge Machining (EDM)
Authors: Zhou Tianfeng , Ma Lizheng , Pang Siqin , Liang Zhiqiang , Wang Xibin
Published: September 2015

Basic experiments are carried out to analyze the size effects on the material removal rate (MRR), electrode wear rate (EWR) and relative loss rate (RLR) in the process of electrical discharge machining (EDM). Then, the relative loss rate is taken as the main criterion to decide the optimal cylindrical electrode size, which is applied to the design of the ring–shaped electrode. Finally, the advantages of the ring–shaped electrode are confirmed by comparing with the traditional plate-shaped electrode in the die-sinking electrical discharge machining experiments.
Manufacturing of a Shape Memory Polymer Actuator
Authors: Santo Loredana , Tedde Giovanni Matteo , Quadrini Fabrizio
Published: September 2015

Shape memory polymer (SMP) foams can be used to manufacture actuators with tailored actuation rate. Being related to foam shape recovery by heating, SMP actuator operates by conversion of heat into motion. In the current study, a SMP linear actuator has been manufactured which is able to apply a maximum load of 50 N (depending on the recovery temperature) and a maximum stroke up to 30 mm. The actuator had a cylindrical shape and its piston had a diameter of 16 mm, therefore a maximum applied pressure about 2.5 bar. The active element (i.e. SMP foam) was produced by solid state foaming of an epoxy resin, and its shaping was performed in the same metallic frame of the actuator. Results show that small and medium-size actuators can be easily produced and operated.
Review on Powder-Bed Laser Additive Manufacturing of Inconel 718 Parts
Authors: Wang Xiaoqing , Gong Xibing , Chou Kevin
Published: September 2015

This study presents a thorough literature review on the powder-bed laser additive manufacturing processes such as selective laser melting (SLM) of Inconel 718 parts. The paper first introduces the general aspects of powder-bed laser additive manufacturing and then discusses the unique characteristics and advantages of SLM. Moreover, the bulk of this study includes extensive discussions of microstructures and mechanical properties, together with the application ranges, of Inconel 718 parts fabricated by SLM.
Development of Si3N4/(W,Ti)C/Co Graded Nano-Composite Ceramic Tool and its Performance in Turning GH2132 Alloy
Authors: Tian X. H. , Zhao J. , Gong F. , Qin W. Z. , Xu Q. Z.
Published: September 2015

Strength and fracture toughness of ceramic tool materials can be enhanced by adding ductile phases. However, the hardness will be decreased, which is undesirable especially for cutting tool materials. Combining with functionally gradient materials (FGMs), the mechanical properties can be tailored so as to achieve high hardness at the outside of the ceramic materials leaving a relatively tough core inside. In this paper, a Si3N4/(W, Ti)C/Co graded composite ceramic tool material was fabricated by hot pressing technique. The composites without Co were used as the surface layers and the composites containing Co were used as the inner layers. Subsequently, the cutting performance of the graded ceramic cutting tool in turning iron-based high temperature alloy GH2132 was studied in comparison with common reference tool. The cutting forces, cutting temperature, tool wear modes and failure mechanisms were discussed. Results revealed that the resultant cutting forces firstly decrease and then increase with the increase of cutting speed, while the maximum cutting temperature increases gradually. Tool live of the FGM tool exceeds that of the corresponding common ceramic tool with the same composition systems. Formation of the residual compressive stress in the surface layer induced by the graded structure contributed to the longer tool life. The main failure modes of the FGM tool were adhesion, groove wear on the rake face and notch wear on the flank face. The graded tool shows better notch wear resistance than the common reference tool.
Joint Maintenance and Energy Management of Sustainable Manufacturing Systems
Authors: Yao Xufeng , Sun Zeyi , Li Lin , Shao Hua
Published: September 2015

The expenses associated with maintenance activities and energy consumption account for a large portion of the total operation cost in manufacturing plants. Therefore, effective methods that can be used for smart maintenance decision-making and energy management to reduce the costs of these two sections and improve the competitiveness of manufacturing enterprise are of high interests to industry. Many efforts focusing on maintenance decision-making and energy management have been dedicated. However, most of the existing research focusing on these two topics has been conducted separately, very little work has been done from a joint perspective that considers the benefits from both manufacturing machine reliability improvement and energy cost reduction. In this paper, a joint maintenance and energy management method is proposed to identify the maintenance actions considering energy cost as well as other equipment health metrics. A numerical case based on a section of an automotive assembly line is used to illustrate the potential benefits of the proposed approach.
Cutting Tool Condition Monitoring and Prediction Based on Dynamic Data Driven Approaches
Authors: Wu Zhenhua
Published: September 2015

In this paper, monitoring and prediction of cutting tool wear condition based on dynamic data driven approaches were investigated. Sensor signals obtained from the machining processes were processed through wavelet denoising to filter the noise un-related to cutting, features in time and frequency domains were extracted using classical signal processing approaches, and then were selected with Pearson correlation coefficient. The most related features were sent to the feature fusion approaches including neural network (NN), adaptive neural fuzzy inference system (ANFIS), or support vector regression (SVR) to estimate the tool wear. Statistics performance evaluation based on correlation coefficient (R2), average absolute error (AAE), and Se/Sy, as well as cross validation, selected the most proper feature fusion approach. Further, prediction models based on Bayesian model average were applied to predict the future tool wear. A case study based on the end mill experiment with signals of 3-axis cutting forces, 3-axis vibrations and acoustic emission, illustrated the proposed approach. It showed that ANFIS has the best estimation accuracy with the R2 of 0.99, AAE of 0.42, Se/Sy of 0.12, and cross validation error of 13.36. In the prediction stage, the prediction model has high prediction accuracy with all the experiment results covered by 95% confidence interval of prediction.
Needle Insertion Force Model for Haptic Simulation
Authors: Gordon Adam , Kim Inki , Barnett Andrew C. , Moore Jason Z.
Published: September 2015

Percutaneous medical procedures rely upon clinicians performing precise needle insertion in soft tissue. The utility of haptic simulation systems in training clinicians for these procedures is highly dependent upon the ability to render accurate insertion force feedback. This paper presents a piecewise mathematical model for insertion force that does not require tissue material properties, detailed mechanical approximations, or complex computations. With manipulation of model parameters, a wide variety of insertion tasks and clinical scenarios can be modeled. Through needle insertion experiments and parameter estimation, this model was demonstrated to replicate the insertion forces associated with a variety of needle and tissue types. In 11 of 12 needle and tissue combinations tested, the model replicated the insertion force with an average absolute mean error of less than 0.065 N.
Effect of Tool Wear on Hole Quality in Drilling of Carbon Fiber Reinforced Plastic-Titanium Stacks Using Tungsten Carbide and PCD Tools
Authors: Kim Dave (Dae-Wook) , Beal Aaron , Kwon Patrick
Published: September 2015

This paper reviews the nature of hole defects and postulates the cause of hole defects resulting from the drilling process of Carbon Fiber Reinforced Plastic (CFRP)-Titanium (Ti) stacked panels using tungsten carbide (WC) and polycrystalline diamond (PCD) twist drills. The parameters that describe the hole quality of the CFRP-Ti stacks include CFRP entry hole delamination, hole diameter and roundness, inner hole surface roughness, CFRP hole profile, CFRP-Ti inter-plate damage, and Ti exit burr. They are caused by heat generation during drilling as well as hot Ti chips and adhesion, Ti burr formation, tool instability, and tool geometry change due to tool wear. For the WC drills, large flank wear and margin wear occurred at the high spindle speed condition, resulting in a reduction of the hole size and an increase of the hole roundness and CFRP-Ti interface damage. At the low spindle speed condition, tool geometry was changed due to the large edge rounding. This resulted in large fiber pull-out at the CFRP hole surface. Ti entry burrs caused damage associated with fiber removal and matrix discoloring at the bottom of the CFRP panel and this inter-plate damage was observed to increase with tool wear. When compared with the WC tool at the same speed condition, the PCD drill maintained relatively small hole defects under all parameters.
Estimation of Weld Bead Geometry in Gas Metal Arc Welding of Aluminum Using Electrical Signals and Liquid Surface Model
Authors: Du Hao , Hu S. Jack , Wang Pei-Chung , Li Jingjing
Published: September 2015

While gas metal arc welding of aluminum has been widely implemented in automotive industry, it is prone to process disturbances. Therefore, an effective monitoring method is necessary to ensure the weld quality (e.g., weld bead height, width and penetration). In this study, an online method was developed to estimate the weld bead geometry using the combination of the real time welding signals, characteristics of weld bead geometry and a liquid surface model. The liquid surface model can represent the steady-state geometry of the weld pool with varying characteristics, such as volume, boundary conditions and surface tension. To model the geometry of the weld pool, the weld pool moved and updated its geometry in response to the merging of each new droplet. The detachment time and size of the new droplet were obtained by analyzing real time welding voltage and current. The surface tension was characterized by the effective contact angle measured under various welding conditions. Moreover, the effective contact angles and radius of arc-affected zone were introduced to significantly simplify the complicated thermal behavior during welding. Finally, the weld bead geometry was estimated using real welding signals in both globular and spray transfer modes and validated with the experimental results. This method predicts weld bead geometry with satisfied accurancy for engineering use and in a comparable speed as the welding speed; and thus can be applied as an online monitoring method for the weld bead quality.
Graphene Oxide Colloidal Suspensions as Cutting Fluids for Micromachining: Part 2 — Droplet Dynamics and Film Formation
Authors: Chu Bryan , Samuel Johnson
Published: September 2015

Part-2 of this paper is focused on studying the droplet spreading and the subsequent evaporation/film-formation characteristics of the graphene oxide colloidal solutions that were benchmarked in Part-1. A high-speed imaging investigation was conducted to study the impingement dynamics of the colloidal solutions on a heated substrate. The spreading and evaporation characteristics of the fluids were then correlated with the corresponding temperature profiles and the subsequent formation of the residual graphene oxide film on the substrate. The findings reveal that the most important criterion dictating the machining performance of these colloidal solutions is the ability to form uniform, sub-micron thick films of graphene oxide upon evaporation of the carrier fluid. Colloidal suspensions of ultrasonically-exfoliated graphene oxide at concentrations < 0.5 wt% are best suited for micromachining applications since they are seen to produce such films. The use of thermally-reduced graphene oxide suspensions at concentrations < 0.5 wt% results in non-uniform films with thickness variations in the 0–5 μm range that are responsible for the fluctuations seen in the cutting force and temperatures. At concentrations ≥ 0.5 wt%, both the thermally-reduced and ultrasonically-exfoliated graphene oxide solutions result in thicker and non-uniform films that are detrimental for machining results. The findings of this study reveal that the characterization of the residual graphene oxide film left behind on a heated substrate may be an efficient technique to evaluate different graphene oxide colloidal solutions for cutting fluids applications in micromachining.
Temperature Simulation and Control System for Automobile Coating Line Drying Rooms
Authors: Jiang Zhaoliang , Liu Wenping , Wei Qingyue , Li Zhishen
Published: September 2015

Product manufacturing systems are one of the largest energy consumers. Focusing on the production of the automobile body coating in particular, the authors investigate the drying system of coating line to improve the energy efficiency during the drying process of the parts. First, The flow field of a drying room is simulated with FEM. Then, an applicable regulation system for controlling the energy loss is built. The proposed method effectively improves the energy utilization of the drying system; thus, decreasing energy loss.
Energy Assessment Methodology for Mechanical and Electrical Product Assembly Processes
Authors: Feng Shaw C. , Kumaraguru Senthilkumaran , Sun Xiufang
Published: September 2015

This paper prescribes an energy assessment methodology, including the procedure and mathematical foundation for evaluating total use and efficiency, for mechanical and electrical product assembly processes. The majority of major manufacturers assemble components and subsystems often produced by suppliers in their supply chains. Differing measurement processes of resource use in product assembly processes yield discrepant resource use assessments. We developed a sequence of activities, including goal setting, defining baselines, measurement, analysis, reporting, evaluation, and resetting the goal for product assembly processes. These activities are to be pursued in an iterative process leading to incremental improvements towards achieving sustainable manufacturing. An application example of reflow soldering was used for verification of the proposed new process’ representativeness and completeness. This methodology provides a guideline for manufacturers to make sound decisions that can be tightly integrated with their business strategy.
Determination of Sustainable Design-Centered Factors for Manufacturing Bioprinting Material of Polylactic Acid
Authors: Wang Steve Hsueh-Ming , Chang Shu-Ping , Shi Jing
Published: September 2015

Sustainable design-centered manufacturing (SDM) is a competitive advantage for new product development. In this research, we determine the SDM factors for Polylactic Acid (PLA) production from cradle to gate. PLA is a mainstream material for bioprinting. We utilize a holistic method to determine the most sensitive and significant sustainability factors among economic, environmental, and social pillars, by adopting ISO 14040 and 14044 frameworks, life cycle cost analysis, and regression analysis methods. The results show that three major sustainability impact factors are profit, water consumption, and health and wellness effects, and the corresponding strategies are proposed. As a result, SDM can help increase profitability, create positive social impacts, reduce waste of resources, and utilize resources with efficiency.
Energy Intensity and Quality of Recyclate in Composite Recycling
Authors: Shuaib Norshah A. , Mativenga Paul T.
Published: September 2015

Composite materials are widely used in various sectors such as aerospace, wind energy and automotive. The high demand especially for thermoset based glass (GFRP) and carbon fibre reinforced polymer (CFRP) composite materials has led to a rise in volumes of manufacturing scrap and end-of-life products as composite waste. Unlike thermoplastic polymers, thermoset polymers have difficulties in recycling due to their cross-linked nature. In this paper, thermoset composite recycling processes which are grouped into mechanical, thermal and chemical methods are assessed from the perspectives of energy consumption, processing rate and mechanical performance of the recycled products. The paper presents a benchmark of composite technologies as well as identifies research challenges.
Cloud Manufacturing Resource Management Based on Metadata
Authors: Zhao Chun , Zhang Lin , Zhang Xuesong , Zhang Liang
Published: September 2015

Centralized management and sharing of manufacturing resources is one of the important functions of cloud manufacturing platform. There are many kinds of manufacturing resources, centralized management, optimized scheduling, quick searching for various manufacturing resources become important issues in a cloud manufacturing platform. This paper presents a resource management model based on metadata to realize the access and unified management of the hardware resources, software resources and knowledge resources. Two management approaches respectively for static and dynamic resource data are introduced to realize resource state monitoring and real-time information collecting. On this basis, the relationship between static and dynamic data is determined and service-oriented of resources is realized.
Layerwise Automated Visual Inspection in Laser Powder-Bed Additive Manufacturing
Authors: Aminzadeh Masoumeh , Kurfess Thomas
Published: September 2015

Laser powder-bed fusion (L-PBF) is an additive manufacturing (AM) process that enables fabrication of functional metal parts with near-net-shape geometries. The drawback to L-PBF is its lack of precision as well as the formation of defects due to process randomness and irregularities associated with laser powder fusion. Over the past two decades much research has been conducted to control laser powder fusion in order to provide parts of higher quality.

This paper addresses online quality monitoring in AM by in-situ automated visual inspection of each layer which is aimed to geometric objects and defects from high-resolution visual images. A scheme for online defect detection system is presented that consists of three levels of processing: low-level, intermediate-level, and high-level processing. Each level is described and appropriately divided to several stages, when insightful. Techniques that are feasible in each level for successful defect detection and classification are identified and described. Requirements and specifications of the measurement data to achieve desired performance of the online defect detection system are stated.

Image processing algorithms are developed for first level of processing and implemented for segmentation of geometric objects. Due to the large variation of intensities within the powder region and fused regions, and also the non-multi-modal nature of the image, the basic segmentation algorithms such as thresholding do not produce appropriate results. In this work, morphological operations are effectively designed and implemented following thresholding to achieve the desired object segmentation. Examples of implementations are given. The paper provides the results of object segmentation which is the initial stage of development of an in-situ automated visual inspection for L-PBF process.
Heat Treatment Response of Steel Fatigue Sample During Vacuum Carburization and High Pressure Gas Quenching Process
Authors: Li Zhichao (Charlie)
Published: September 2015

A hollow R.R. Moore rotation fatigue sample made of AISI 9310 is processed using vacuum carburization and high pressure gas quenching. The vacuum carburization schedule is designed to through carburize the thin wall section of the fatigue sample to 0.7% wt.% carbon, followed by 10 bar nitrogen quench. Some samples showed significant bow distortion after quench hardening, and further investigations indicated that the unbalanced wall thickness from machining is the main cause of the bow distortion. In this paper, DANTE, a commercial heat treatment software is used to study the cooling, phase transformation, and stress evolution during quenching. The effect of unbalance wall thickness on distortion is also investigated. Residual stress state in the quench hardened sample is critical to the fatigue performance during rotational bending fatigue tests. In this study, the unbalanced geometry has insignificant effect on the residual stresses after quench hardening. However, the unbalanced geometry will affect the applied stress significantly during a rotation fatigue test.
Numerical Study of Factorial Impact of Thin Layer Ring on Improving Thermal Performance of Ice Thermal Storage System
Authors: Xie Junling , Yuan Chris
Published: September 2015

Ice thermal storage system is a novel technology used in HVAC&R systems for improving energy efficiency of manufacturing facilities. In this paper, the investigation of ice formation in a typical ice thermal storage system was conducted to study the factorial effect of the new structure of thin layer ring placed in a rectangular cavity filled with water on solidification process. Numerical method was used for the computational solutions of fluid flow domain. The performance of the thin layer ring was successfully demonstrated by achieving an increased ice generation area and shortening the time period of ice formation for a typical ice thermal storage system. More detailed research on material, thickness and arrangement of the ring has been comparatively conducted for heat transfer enhancement. The parameters of thin layer ring from three perspectives have been investigated statistically with nine combinations of model are carried out by combining different levels of each factor via Taguchi Method. The results show the contribution ratio of each factor of thin layer ring on improving energy efficiency of ice thermal storage system.
Sustainability Performance Assessment of Alternate Machining Technologies
Authors: Singh Kuldip , Madan Jatinder
Published: September 2015

A method to assess and compare sustainability performance of alternative machining technologies is presented in this paper. The alternative machining technologies use different techniques for cooling of the tool and work-piece interface. The paper considers three technologies, conventional flood machining (CFM) that uses cooling lubricant fluids (CLFs), cryogenic machining (CryoM) and near dry machining (NDM). An overall sustainability score (OSS) has been proposed that represents sustainability, taking into account three important factors, namely (i) machining cost (ii) quality and (iii) environmental impacts. OSS is used to compare alternative machining technologies with an objective to find the most sustainable machining process. A turning operation case study is conducted to showcase the effectiveness of the proposed method.
Airflow Assisted Electrohydrodynamic Jet Printing: An Advanced Micro-Additive Manufacturing Technique
Authors: Tse Lai Yu Leo , Barton Kira
Published: September 2015

Electrohydrodynamic jet (e-jet) printing is a growing technology for high resolution (<20μm) printing. It enjoys the advantages of other additive manufacturing technologies and is compatible with a large range of materials. E-jet applications include electronic fabrication, high-resolution prototyping, and bio-medical devices. Despite the diverse range of applications, e-jet printing dynamics are sensitive to varying standoff heights and changing electric fields. As such, conventional e-jet printing generally consists of a conductive nozzle printing onto a flat, conductive substrate. To address this limitation, this paper presents an airflow assisted e-jet printhead that is shown to greatly reduce the substrate effects while providing good printing resolution (<15μm). The working principle and design challenges are provided. Experimental demonstrations validate the performance capabilities of the modified e-jet printhead.
Compensations for Tool Path to Enhance Accuracy During Double Sided Incremental Forming
Authors: Lingam Rakesh , Bhattacharya Anirban , Asghar Javed , Reddy N. Venkata
Published: September 2015

Incremental Sheet Metal Forming (ISMF) is a flexible sheet metal forming process that enables forming of complex three dimensional components by successive local deformations without using component specific tooling. ISMF is also regarded as die-less manufacturing process and in the absence of part-specific dies, geometric accuracy of formed components is inferior to that of their conventional counterparts. In Single Point Incremental Forming (SPIF), the simplest variant of ISMF, bending near component opening region is unavoidable due to lack of support. The bending in the component opening region can be reduced to a larger extent by another variant of ISMF namely Double Sided Incremental Forming (DSIF) in which a moving tool is used to support the sheet locally at the deformation zone. However the overall geometry of formed components still has unacceptable deviation from the desired geometry. Experimental observation and literature indicates that the supporting tool loses contact with the sheet after forming certain depth. Present work demonstrates a methodology to enhance geometric accuracy of formed components by compensating for tool and sheet deflection due to forming forces. Forming forces necessary to predict compensations are obtained using force equilibrium method along with thickness calculation methodology developed using overlap that occurs during forming (instead of using sine law). Results indicate that there is significant improvement in accuracy of the components produced using compensated tool paths.
Basic Investigations in Incremental Profile Forming
Authors: Grzancic Goran , Becker Christoph , Ben Khalifa Nooman , Tekkaya A. Erman
Published: September 2015

Increasing demands in profile manufacturing lead to a constant increase of the geometric complexity of the profile. Especially in times where lightweight design and load adaption are of huge importance, a need for new profile manufacturing technologies exists. In order to cope with this development a new profile forming method was invented, the Incremental Profile Forming (IPF). IPF allows the flexible manufacturing of profiles with varying cross section geometries along the longitudinal profile axis and offers therefore high potential for the manufacturing of lightweight design parts. Due to the high degree of innovation research work regarding the process fundamentals as well as the process limits is necessary. For this reason, the results of the first basic experimental and numerical investigations are presented. While in the experiments the potential of the process is shown in feasibility studies, first analysis of the forming process as well as the influence of diverse process parameters on the process was carried out in numerical investigations. Finally first analytical approaches for predicting the forming behavior are presented.
Nanocrystalline Diamond Coated Tool Performance in Machining of LM6 Aluminium Alloy/Alumina MMC
Authors: Kannan Ramasubramanian , Narayanaperumal Arunachalam , Rao Mamidanna Sri Ramachandra
Published: September 2015

Aluminium based metal matrix composites (MMC) gain its importance in automotive and aerospace applications due to their high strength to low weight ratio, which leads to reduced fuel consumption and improved performance. However the usage of MMC is limited due to its poor machinability. The presence of hard reinforcing particles in MMC makes these materials difficult to machine. A cutting tool with high hardness and low coefficient of friction is required for machining this MMC material effectively. In this paper a comparative study on machinability of different coated tools on LM6 aluminum alloy/alumina MMC are conducted and presented. Experimental results on tool wear, cutting force and surface finish indicate that nano-crystalline diamond coated tools (NCD) outperform the other commercially available coated tools for machining this metal matrix composites.
Investigation of Finite Element Thermal Models for Workpiece Temperature in Cylinder Boring
Authors: Chen Lei , Yang Juhchin A. , Shih Albert J. , Tai Bruce L.
Published: September 2015

The accuracy and computational efficiency of four finite element thermal models for workpiece temperature in cylinder boring are studied. High temperature in precision cylinder boring of automotive engine block can distort the workpiece, leading to thermally-induced dimensional and geometrical errors. In cylinder boring, the depth of cut is small compared to the bore diameter, so a fine mesh is usually needed to analyze the workpiece temperature distribution; however fine mesh on a relatively large workpiece also takes extensive computational resources. To understand the trade-off between accuracy and computational efficiency, the advection, surface heat, heat carrier, and ring heat finite element thermal models are introduced and compared quantitatively in a boring process. It is found comparable global temperature estimation from all four models. For the temperature near the cutting zone, the advection and surface heat models are more accurate to predict local temperatures but consume more computational resources. The heat carrier model predicts the surface temperature with reasonable accuracy and computational time. The ring heat model is the most computationally efficient but fails to accurately estimate local peak temperatures.
Machining Force Modeling of Vibration-Assisted Nano-Machining Process
Authors: Kong Xiangcheng , Zhang Li , Dong Jingyan , Cohen Paul H.
Published: September 2015

Nanofabrication technology is very important for many emerging engineering and scientific applications. Among different nanofabrication technologies, vibration-assisted nano-machining provides a low cost easy-to-setup approach to produce structures with nano-scale resolution. It is critical to understand the mechanism for the nano-machining process and predict the cutting force, so as to provide guidelines to achieve higher productivity and reduce tip wear. In this article, a machining force model for tip-based nano-machining process is developed and validated. We analyze the instantaneous engagement area between cutting tool (AFM tip) and workpiece (PMMA film) at the given tip position for the vibration-assisted nano-machining process. A discrete voxel method is adopted to calculate the material removal rate at each moment, and an empirical machining force model is developed by correlating the cutting force with material removal rate. The model was verified by experiments over a large range of machining conditions, and the coefficients and parameters in the force model was obtained using Mean Square Error (MSE) method by comparing the predicted machining force from the force model and measured machining force from experiments. The results show good fit between predicted machining force and measured machining force.
Locally Applied Direct Electric Current’s Effect on Springback of 2024-T3 Aluminum After Single Point Incremental Forming
Authors: Ruszkiewicz Brandt J. , Roth John T. , Johnson David H.
Published: September 2015

Incremental forming is a sheet metal forming technology that utilizes a spherical tipped tool and a CNC machine to form a part through a series of spiraling tool paths. Springback is one of the largest concerns for incremental forming since a part can be the exact shape desired after forming until the part is unclamped from its forming fixtures, at which point it will springback due to the residual stresses resident in a part due to the forming process. This paper demonstrates how locally applied electric current can be utilized to reduce the springback due to residual stresses. The tests conducted in this paper demonstrate this concept via incrementally formed truncated-pyramid shapes that were formed from 2024-T3 aluminum. The residual stress concentration locations of the pyramid were determined using FEA. Direct electric current was locally applied to the stress concentrations of the pyramid prior to unclamping. Various current densities, time intervals, and electrical pulse locations were examined to find the ideal conditions for reducing springback for a tested geometry of 2024-T3 aluminum.
Direct Electric Current Spot Treatment’s Effect on Springback of 90 Degree Bent 2024-T3 Aluminum
Authors: Ruszkiewicz Brandt J. , Scriva Christopher , Reese Zachary C. , Nikhare Chetan P. , Roth John T. , Ragai Ihab
Published: September 2015

One of the largest issues for sheet metal forming techniques such as stamping and incremental forming is springback. Springback is the elastic recovery of a material after it has been formed resulting in distorted part geometries. Springback can be compensated for during the forming process, however, this often requires forming the metal further than the desired shape. Unfortunately, if a formed part is designed such that it is close to its forming limit, compensation could push the material too far and cause fracture. It has been shown that by pulsing electric current throughout an entire workpiece during forming, springback can be greatly reduced and sometimes eliminated.

This paper examines the effect of pulsing direct electric current, through localized points of a workpiece after it has been deformed into a 90-degree bend, but prior to the reversal of the bending die (i.e., while the part is still constrained). It was found that, with a high current density for a short amount of time, springback could be greatly reduced without the need to run a larger current through the entire workpiece. The largest springback reduction was seen when the electric current was forced to flow across the bend in the specimen. This finding is advantageous for industry as it will allow springback reduction in large parts that would normally require much larger power sources to generate the correct current density, if current is run through the entire part. A potential barrier between industry and this technology is that machines would need to be either created or modified to apply electric current at known places at a specific current density and time. To modify an existing machine may be difficult because the machine would need to be insulated from the electric current.
Effect of Thermal Assistance on the Joining of Al6063 During Flow Drill Screwdriving
Authors: Skovron Jamie D. , Ulutan Durul , Mears Laine , Detwiler Duane , Paolini Daniel , Baeumler Boris , Claus Laurence
Published: September 2015

An increase in fuel economy standards has affected automakers’ decision toward designing lightweight vehicles and therefore transitioning from steel-based bodies to ones predominantly composed of aluminum. An introduction to lightweight materials couples that of lightweight joining with a thermo-mechanical process, Flow Drill Screwdriving (FDS). This process is favored in terms of robustness, short installation time, and only requiring access to one side. The most significant challenge of this process is reducing the material sheet separation to minimize any possibility of corrosion buildup. Warm forming of aluminum has been shown to increase ductility and formability of the material and thus the process benefits from a reduced cycle time that leads to cost reduction. In this study, the effect of an auxiliary heat source on the flow of Al6063 is investigated for the FDS application. In order to accomplish this task, a conduction-heating ring is implemented into the FDS process to raise the material temperature and thus reduce the total cycle time. Different preprocess material temperatures are studied to determine the effect of material temperature on the process time, installation torque, and sheet separation. As a result, with the thermal assistance, a reduction in the process time up to 52%, the maximum installation torque by 20%, and sheet separation by 11% were attained, indicating better quality joints at a lower cost.
Additive Manufacturing of CFRP Composites Using Fused Deposition Modeling: Effects of Carbon Fiber Content and Length
Authors: Ning Fuda , Cong Weilong , Wei Junhua , Wang Shiren , Zhang Meng
Published: September 2015

Additive manufacturing (AM) technologies have been successfully applied in various applications. Fused deposition modeling (FDM), one of popular AM techniques, is most widely used method for manufacturing of plastic materials. Due to the poor strength properties of pure plastic materials, there is a critical need to improve mechanical properties for FDM-fabricated pure plastic parts. One of the possible methods is adding reinforced materials (such as carbon fibers) into plastic materials to form carbon fiber reinforced plastic (CFRP) composites. The investigation in this paper is going to test if the properties of CFRP composites part will be enhanced compared with pure plastic part made by FDM. There are three major steps in this paper including producing thermoplastic matrix CFRP composites filaments extruded after blending plastic pellets and carbon fiber powder, printing parts in FDM process, and conducting tensile test. Effects of carbon fiber content and length on the mechanical properties (tensile strength, Young’s modulus, toughness, ductility, and yield strength) of specimens are investigated. This investigation will also provide guidance for future investigations of fabricating thermoset matrix CFRP composites by AM techniques.
Real-Time Maintenance Policy in Manufacturing Systems With Intermediate Buffers
Authors: Gu Xi , Jin Xiaoning , Ni Jun
Published: September 2015

Real-time maintenance decision making in large manufacturing system is complex because it requires the integration of different information, including the degradation states of machines, as well as inventories in the intermediate buffers. In this paper, by using a discrete time Markov chain (DTMC) model, we consider the real-time maintenance policies in manufacturing systems consisting of multiple machines and intermediate buffers. The optimal policy is investigated by using a Markov Decision Process (MDP) approach. This policy is compared with a baseline policy, where the maintenance decision on one machine only depends on its degradation state. The result shows how the structures of the policies are affected by the buffer capacities and real-time buffer levels.
Arbitrary Lagrangian Eulerian FEA Method to Predict Wavy Pattern and Weldability Window During Magnetic Pulsed Welding
Authors: Nassiri Ali , Chini Greg P. , Kinsey Brad L.
Published: September 2015

Finite element simulations of high strain rate forming processes have received significant attention over the last decade. For instance, in Magnetic Pulsed Welding (MPW), extremely high plastic strain regions develop. Thus, a traditional pure Lagrangian analysis is not able to accurately model the process due to excessive element distortion near the contact zone. In this study, the Arbitrary Lagrangian Eulerian (ALE) method is used to simulate a MPW process while retaining a high-quality mesh. Also the ALE method was able to numerically predict the necessary process parameters to achieve a wavy pattern region for two Al6061-T6 plates impacted during the MPW process. The captured wavy pattern region in this study can be used as a first estimation of parameters necessary to achieve a successful MPW component and thus reduce trial and error experimental investigations.