bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Investigation of Vibration Assisted Helical Milling of 7075 Aluminum Alloy
Authors: Ali Mariam N. , El-Hofy Hassan
Published: November 2019

Vibration-assisted helical milling (VAHM) is a novel machining process in which an axial ultrasonic vibration is superimposed to the milling cutter. The current work aims to experimentally investigate the influence of applying ultrasonic vibration on the machining performance during helical milling of 7075 aluminum alloy. A full factorial design of experiment is first implemented. Analysis of Variance (ANOVA) is then performed to study the effect of rotational speed (n), tangential feed (Ft), helical pitch (P) and ultrasonic vibration on the process performance. The output response variables considered in this investigation are cutting forces (axial, tangential and radial), torque and hole quality in terms of out-of-roundness, hole size error and surface roughness. The results show that the best cutting conditions to minimize the cutting forces and the diameter deviation are the rotational speed of 5000 rpm, tangential feed of 100 mm/min and helical pitch of 0.1 mm/rev with the assistance of the ultrasonic vibration. The ultrasonic vibration improves the performance of helical milling by decreasing the axial cutting forces.
Real-Time Prognostic and Dynamic Maintenance Window Scheme for Reconfigurable Manufacturing Systems
Authors: Dong Yifan , Xia Tangbin , Xiao Lei , Pan Ershun , Xi Lifeng
Published: November 2019

Real-time condition acquisition and accurate time-to-failure (TTF) prognostic of machines are both crucial in the condition based maintenance (CBM) scheme for a manufacturing system. Most of previous researches considered the degradation process as a population-specific reliability characteristics and ignored the hidden differences among the degradation process of individual machines. Moreover, existing maintenance scheme are mostly focus on the manufacturing system with fixed structure. These proposed maintenance scheme could not be applied for the reconfigurable manufacturing system, which is quite adjustable to the various product order and customer demands in the current market. In this paper, we develop a systematic predictive maintenance (PM) framework including real-time prognostic and dynamic maintenance window (DMW) scheme for reconfigurable manufacturing systems to fill these gaps. We propose a real-time Bayesian updating prognostic model using sensor-based condition information for computing each individual machine’s TTFs, and a dynamic maintenance window scheme for the maintenance work scheduling of a reconfigurable manufacturing system. This enables the real-time prognosis updating, the rapid decision making for reconfigurable manufacturing systems, and the notable maintenance cost reduction.
Conceptualization and Design of a Low-Cost MTConnect-Enabled Refractometer for Coolant Health Monitoring
Authors: Feldhausen Thomas , Hirani Asimm , King Walter , Lynn Roby , Kurfess Thomas
Published: November 2019

Monitoring of the health of water-based coolant used for machining requires measurement of various parameters of the coolant, including refractive index, temperature, pH, and turbidity. One of the primary parameters that is used to determine the concentration of the coolant is the refractive index, which is typically measured manually by an operator at regular intervals during machine operation. This paper describes the conceptualization and preliminary design of a coolant health monitoring system that will automatically measure the refractive index of the coolant and will digitize the resulting measurement for communication to a factory supervisory control and data acquisition (SCADA) system. To enable rapid integration into a factory’s network architecture, the coolant concentration measurement will be transmitted by the monitoring system using the MTConnect format. Having an MTConnect-enabled sensor will allow the data to be remotely aggregated and compared to other machine data to help give a better understanding of overall machine health. The economical approach to its design allows the coolant health monitor to be realizable for both small manufacturing enterprises (SMEs) and large manufacturers alike. This widespread implementation will further benefit industry’s movement toward Internet-of-Things (IoT)-equipped manufacturing facilities.
Out-of-Autoclave Repair of Composite Laminates by Using Shape Memory Polymer Foams
Authors: Bellisario D. , Quadrini F. , Santo L. , Iorio L. , Gallo N. , Corvaglia S.
Published: November 2019

Composite repairing is an issue because of the size of the parts, the cost of the production equipment and the poor consolidation between the parent part and the repairing patches. In this study an out-of-autoclave procedure is proposed where the agglomeration pressure is provided by shape memory foams. These foams can be shaped in the desired form by means of a thermos-mechanical cycle, and provide additional pressure if constrained during recovery. Shape recovery is achieved by using the same thermal cycle which is necessary for the cure of the patches. In this study, thermoplastic shape memory foams have been characterized to evaluate the agglomeration pressure they can provide as a function of the compression strain. In order to show the feasibility of their application, the cure of a composite laminate has been performed by using pre-shaped shape memory foams. Results show that a good consolidation is achieved despite of the absence of a vacuum bag.
Conformal Circuit Fabrication via Flash Light Sintering and Forming
Authors: Devaraj Harish , Malhotra Rajiv
Published: November 2019

This paper investigates sequential Thermoforming and Flash Light Sintering (FLS) of conductive silver nanowire interconnects printed on planar polymer sheets. The resulting interconnect-polymer assemblies are pre-shaped to a desired 3D geometry and can be robustly attached to the surface. This approach avoids interconnect delamination in manual conformation of planar flexible electronics, eliminates heating of the 3D object in direct conformal printing, and enables easy circuit replacement. The effect of the forming strain and FLS fluence on the resistance of the interconnect are studied. The interconnect resistance increases after thermoforming but is reduced significantly by subsequent FLS. The resistance depends nonlinearly on the forming strain, interconnect thickness, and FLS fluence. With the optimal parameters found here this process achieves interconnect resistance of < 10 Ω/cm within 90.8 seconds at 100% maximum strain over a 1 square-inch forming area. The application of this process for complex surfaces is demonstrated via a simple conformal LED-lighting circuit.
Laser Direct Energy Deposition Welding of AISI 316 Stainless Steel Sheets
Authors: Ascari Alessandro , Fortunato Alessandro , Liverani Erica , Lutey Adrian H. A.
Published: November 2019

The present paper assesses the applicability of laser powder direct energy deposition for welding of thin stainless steel sheets. Considering the rapid development of laser cladding and relatively wide range of equipment available in modern industrial settings, this technology can also be applied to laser welding, where the procedure is performed with a filler material comprising blown powder. To this end, an exhaustive experimental campaign has been carried out with the aim of evaluating the influence of the main process parameters, including laser power and powder feed rate, on the resulting weld bead characteristics. Two joint configurations have also been considered to assess the best solution in terms of both chamfer shape and sheet positioning. Butt and lap joints were prepared, with 30° and 45° V-groove configurations tested and characterized in the former case. In order to assess the resulting weld quality, metallographic analyses were carried out to measure the main morphological parameters of the weld beads, including width, penetration depth and reinforcement, and to evaluate the possible presence of defects such as pores, cracks or lack of melting. Tensile tests were also carried out with the purpose of characterizing the overall mechanical performance of the joints. These tests demonstrated good overall process feasibility and highlighted the fact that lap joints and 30° V-groove butt joints were the best configurations in terms of both weld bead quality and fused zone morphology.
Singular Vector-Inspired Dictionary Learning for Sparse Decomposition of Vibration Signal
Authors: Ding Baoqing , Yan Ruqiang , Wang Shibin , Tong Chaowei , Chen Xuefeng
Published: November 2019

Dictionary design is a primary challenge for sparsity-assisted fault diagnosis techniques. The dictionary can either be specified through signal priors or learned from data samples. In this paper, we propose a singular vector-inspired dictionary learning (SVDL) method, combining signal priors and data samples for sparse decomposition of machinery vibration signal. The SVDL is a data driven scheme for learning dictionary atoms and simultaneously exploring the prior information. It is achieved by alternating between atom design and dictionary update steps. First, we introduce the singular vector as vibration signal priors to atom design procedure. Through singular value decomposition on the Hankel matrix of the vibration signal, the inherent signal features corresponding to mechanical fault can be expressed with some singular vectors. These vectors, closely related to fault features, are extracted as basis vectors to constitute atoms. Second, the vector quantization method is used for atom design, by clustering the extracted basis vectors for the purpose of learning representative atoms. As to the dictionary update step, a strategy including sparse coding and dictionary optimization is adopted to simplify and update atoms. The results of the numerical simulation and experimental application show that the proposed SVDL method outperforms the classical K-SVD method for vibration signal denoising and fault feature extraction.
Exploring the Multi-Stage Effects of Material Preparation and Printing on 3D Printing Product Quality
Authors: Hajifar Sahand , Purnanandam Ramanarayanan , Sun Hongyue , Zhou Chi
Published: November 2019

3D printing is a promising technique to fabricate flexible parts and reduce the supply chain. Various materials, such as metal powders, plastics, ultraviolet (UV) sensitive resins, can be fabricated from 3D printing and form the final printed part. Currently, most researchers either focus on exploring printable materials with good property or focus on the process quality control given a certain type of material. However, for many 3D printing processes, the printing process and product properties are dependent on both the material properties and process settings. To the best of the authors’ knowledge, the quantitative analysis of the interactions of material properties and printing process settings are rarely studied. In this paper, we treat the material preparation and 3D printing as different manufacturing stages, and we explore the multi-stage effects in 3D printing. In particular, we add carbon fiber to the CLEAR resin to alter the material properties for a stereolithography (SLA) 3D printing process. It is observed that the part properties are jointly affected by material properties and printing process settings. Therefore, the material property and process settings should be jointly considered for optimizing 3D printing processes.
Sensitivity Analysis Between Error Motions and Machined Shape Errors in Five-Axis Machining Centers: In Case of S-Shaped Machining Test by a Square End Mill
Authors: Li Zongze , Sato Ryuta , Shirase Keiichi , Ihara Yukitoshi
Published: November 2019

Five-axis machining center, combined three linear and two rotary axes, has been increasingly used in complex surface machining. However, as the two additional axes, the machined surface under table coordinate system is usually different from the tool motion under machine coordinate system, and as a result, it is very tough to predict the machined shape errors caused by each axes error motions. This research presents a new kind of sensitivity analysis method, to find the relationship between error motions of each axis and geometric errors of machined shape directly. In this research, the S-shaped machining test is taken as a sample to explain how the sensitivity analysis makes sense. The results show that the presented sensitivity analysis can investigate how the error motions affect the S-shaped machining accuracy and predicted the influence of error motions on certain positions, such as the reversal errors of the axes around motion reversal points. It can be proved that the presented method can help the five-axis machining center users to predict the machining errors on the designed surface of each axes error motions.
The Quality of Slicing Technologies for Digital Light Processing 3D Printing
Authors: Kwok Tsz-Ho
Published: November 2019

The process planning of a manufacturing method is the key to ensure the quality of the fabricated part. In Additive Manufacturing (AM), slicing is a crucial step in process planning to convert a Computer-Aided Design (CAD) model to a machine-specific format. If the slicing results were incorrect, the manufacturing quality would have no way to be assured. Therefore, it is important to understand the performance of different slicing technologies for AM. Digital Light Processing (DLP) printing is an important AM process that has a good surface finish, high accuracy and fabrication speed, and is widely applied in many dental and engineering industries. However, while most other AM processes are toolpath-based, as a process that uses images as the fabrication tool, the DLP printing has its process planning understudied. Therefore, the main goal of this paper is to study, compare and benchmark the slicing technologies for DLP printing. Three slicing technologies are compared: contour, voxelization, and ray-tracing. They are tested with some common defects in slicing, and their usage in computational resources is also reported. The summary and suggestion are given at the end.
The Realities of Friction in Metal Plastic Flow With Corresponding Results During Metal Cutting
Authors: Lortz Wolfgang , Pavel Radu
Published: November 2019

Metal cutting is a dynamic process with two types of friction: on the one hand, external friction between two different bodies, and on the other hand, an internal friction inside the same material, due to plastic flow. These two different types of friction lead to different chip formation processes. In the case of built-up-edge (BUE), low velocity creates low energy, resulting in a self-hardening effect with BUE. With increasing velocity, the energy will increase and will result in high temperatures with a built-up-layer (BUL). Furthermore, under special circumstances, friction will lead to a self-blockade (a self-blocking state). This situation describes the third stage in metal plastic flow — the creation of a segmental chip. In this case the internal friction takes over.

One question arises: “How can we determine these two types of different friction?” For solving these phenomena new fundamental equations based on mathematics, physics and material behavior have to be developed. This paper presents newly developed equations, which deliver the theoretical distribution of yield shear stress as well as strain rate with corresponding grid deformation pattern in metal plastic flow. For an actual cut, the plastic deformation pattern remains when the process is stopped, and therefore the theoretical result can be compared with cross-sections of the relevant chip formation areas — contrary to outputs such as stress, strain rate and temperatures which are all functions of position and time.

All this will be shown and discussed in the paper, and stands in good agreement with experimental results.
A Hybrid Approach for Heterogeneous High-Density Data for Surface Topology Classification: A Case Study
Authors: Dastoorian Romina , Wells Lee , Tian Wenmeng
Published: November 2019

Recent measurement system developments have brought new opportunities to enhance the performance of quality control (QC) systems in manufacturing. Digital cameras and 3D optical scanners are among the advanced measurement systems that can represent an entire product’s surface. These data-rich environments have been widely used in automated surface defect detection. However, despite the fact that datasets from both digital cameras and 3D optical scanners can both represent a surface, the datasets are fundamental different and contain different information regarding a part’s surface. Extensive research efforts have been conducted on developing QC tools for each of these datasets individually, very few researches were focused on approaches to take advantage of both 3D point clouds (obtained from technologies such as 3D optical scanners) and digital images (obtained from digital cameras) at the same time. This paper proposes a hybrid approach for surface inspection of additive manufacturing parts through Multilinear Principal Component Analysis (MPCA). This proposed approach is demonstrated with additively manufactured parts, which shows the advantage of combining this information for surface classification.
Modeling for Chemical-Etching Enhanced Pulsed Laser Ablation
Authors: Zhang Xing , Mao Bo , Histed Rebecca , Liao Yiliang
Published: November 2019

Pulsed laser ablation (PLA) under active liquid confinement, also known as chemical etching enhanced pulsed laser ablation (CE-PLA), has emerged as a novel laser processing methodology, which breaks the current major limitation in underwater PLA caused by the breakdown plasma and effectively improves the efficiencies of underwater PLA-based processes, such as laser-assisted nano-/micro-machining and laser shock processing. Despite of experimental efforts, little attention has been paid on CE-PLA process modeling. In this study, an extended two-temperature model is proposed to predict the temporal/spatial evolution of the electron-lattice temperature and the ablation rate in the CE-PLA process. The model is developed with considerations on the temperature-dependent electronic thermal properties and optical properties of the target material. The ablation rate is formulated by incorporating the mutual promotion between ablation and etching processes. The simulation results are validated by the experimental data of CE-PLA of zinc under the liquid confinement of hydrogen peroxide.
Analysis of Polycrystalline Diamond Micro-Grinding Tool Topography Using Image Processing
Authors: Pratap Ashwani , Patra Karali
Published: November 2019

Polycrystalline diamond (PCD) micro-grinding tools are shaped using different electro-discharge machining processes among which wire electro-discharge grinding (WEDG) process is widely accepted due to its capability of producing highly precise, ultra-thin and dimensionally accurate tools. Topographical analysis of the tool surface is inevitable as abrasive cutting edge density and grit protrusion heights affect the cutting process and are equally demanding parameters in modeling of the process. Analysis of micro-grinding tool topography and determining the tool surface statistics have always been a vital challenge due to random positioning and orientation of the abrasives on the tool surface. Current study deals with dressing of polycrystalline diamond micro-tool using wire-electro-discharge grinding and thereafter analysis of tool surface topography using novel image processing technique. In contrast to most of the previous experimental studies based on wheel replication and touch probe data to analyze the conventional grinding tool surface, we develop a sequential methodology using various available image processing algorithm tools and its application on the actual 3D surface data of the miniature sized PCD tool to capture the abrasive density and protrusion heights distribution. It is observed that image processing employing leveling, threshold, watershed algorithm and edge detection provided accurate outlook into the tool surface. Static cutting edge density is found to be 165–170 grits (per mm) and its variation with respect to depth into tool surface is also observed.
Surface Modifications of Titanium With Covalently-Bonded Silver Nanoparticles for Antimicrobial Applications
Authors: Maharubin Shahrima , Shu Xiaomei , Singh Manavi , De los Reyes Benildo , Tan George
Published: November 2019

Formation of biofilm on implant surface is one of the major causes for port-operative infection. Incorporation of antimicrobial silver nanoparticles (AgNPs) on implant surface has been studied as an effective remedy in recent decades. This paper presents a novel AgNPs-titanium composite foil manufactured through covalent attachment of AgNPs for biofilm control. This composite foil was fabricated by a series of chemical reactions including thiol-derivatization and formation of Ag-S covalent bonds. The film structure and properties were characterized through scanning electron microscopy (SEM), Energy dispersive X-ray Spectroscopy (EDS) and surface profiling. The antimicrobial performance was examined against gram positive bacterial strain Staphylococcus aureus. Results indicate that the prepared composite foil effectively reduced bacterial attachment in short term exposure and possess high stability against the release of nanoparticles. This novel antimicrobial composite material has a great potential to be used in the future biomedical instrumentation.
Molecular Dynamics Simulation of Nanoparticle Infiltration During Binder Jet Printing Additive Manufacturing Process: A Preliminary Study
Authors: James Sagil , Navarro Cristian
Published: November 2019

Binder Jetting Process involves binding layers of powder material through selective deposition of a liquid binder. Binder jetting is a fast and relatively inexpensive process which does not require a high-powered energy source for printing purpose. Additionally, the binder jetting process is capable of producing parts with extreme complexities without using any support structures. These characteristics make binder jetting an ideal choice for several applications including aerospace, biomedical, energy, and several other industries. However, a significant limitation of binder jetting process is its inability to produce printed parts with full density thereby resulting in highly porous structures. A possible solution to overcome the porosity problems is to infiltrate the printed structures with low-melting nanoparticles. The infiltrating nanoparticles help fill up the voids to densify the printed parts and also aids in the sintering of the printed green parts. In addition to increasing the density, the nanoparticle infiltration also helps improve the mechanical, thermal and electrical properties of the printed part along with bringing multi-functionality aspect. Currently, there is a lack of clarity of the nanoparticle infiltration process performed to improve the quality of parts fabricated through binder jetting. This research employs Molecular Dynamics simulation techniques to investigate the nanoparticle infiltration during binder jetting additive manufacturing process. The simulation is performed at different operating temperatures of 1400 K, 1500 K, and 1600 K. The study found that the infiltration process is significantly affected by the operating temperature. The infiltration height is found to be highest at the operating temperature of 1600 K while the porosity reduction is found to be maximum at 1500 K. The infiltration kinetics is affected by the cohesion of the nanoparticles causing blockage of channels at higher operating temperatures. The simulation model is validated by comparing with the Lucas-Washburn infiltration model. It is seen that the simulation model deviates from the theoretical prediction suggesting that multiple mechanisms are driving the infiltration process at the nanoscale.
Laser Forming of Metal Foam Sandwich Panels: Effect of Panel Manufacturing Method
Authors: Bucher Tizian , Zhang Min , Chen Chang Jun , Verma Ravi , Li Wayne , Yao Y. Lawrence
Published: November 2019

Sandwich panels with metal foam cores have a tremendous potential in various industrial applications due to their outstanding strength-to-weight ratio, stiffness, and shock absorption capacity. A recent study paved the road towards a more economical implementation of sandwich panels, by showing that the material can be successfully bent up to large angles using laser forming. The study also developed a fundamental understanding of the underlying bending mechanisms and established accurate numerical models.

In this study, these efforts were carried further, and the impact of the foam core structure, the facesheet and foam core compositions, as well as the adhesion method on the bending efficiency and bending limit was investigated. These factors were studied individually and collectively by comparing two fundamentally different sandwich panel types. Thermally-induced stresses at the facesheet/core interface were thoroughly considered. Numerical modeling was carried out under different levels of geometric accuracy, to complement bending experiments under a wide range of process conditions. Interactions between panel properties and process conditions were demonstrated and discussed.
Influence of Coating Spray on Surface Measurement Using 3D Optical Scanning Systems
Authors: Yang Yuhang , Chen Siyuan , Wang Letao , He Jingying , Wang Shang-Ming , Sun Luwen , Shao Chenhui
Published: November 2019

High-resolution 3D measurement is crucial for a wide range of applications in manufacturing. With the recent development of optical technologies, the performance of many 3D scanning systems has entered the practical range for object digitizing, reverse engineering, quality control, and many other manufacturing applications. In order to extend the measurement capability to reflective or transparent surfaces, a common practice for reducing the unwanted reflection and refraction is to coat the surfaces with micro-particle spray. There is, however, limited discussion about the influence of coating spray on the resulted measurement precision of 3D optical scanning systems, and due to lack of standardized procedure for spray coating, the variability caused by different operators in surface measurement remains to be examined. This paper investigates the 3D data acquisition of spray-coated surfaces with a structured-light scanning system through experiments and statistical analysis. Both surface roughness and spatial statistics are used to quantitatively evaluate the characteristics of the 3D measurement system. Gauge R&R study is conducted to determine measurement repeatability and reproducibility. The results demonstrate that both the number of spray pass and the skill of the individual operator can significantly affect the performance of the structured-light scanning system. Other pertinent suggestions for the operation of 3D optical scanning systems with spray coating are also provided.
Bearing Metrics for Health Monitoring of Machine Tool Linear Axes
Authors: Vogl Gregory W. , Galfond Brian C. , Jameson N. Jordan
Published: November 2019

Diagnostics and prognostics of rotating machinery ball bearings is quite mature with an abundance of available methods and algorithms. However, extending these algorithms to other ball bearing applications is challenging and may not yield usable results. This work used a linear axis to study the ability of an inertial measurement unit (IMU), along with nine signal features, to measure changes in geometric error motions due to induced faults on the recirculating ball bearings of two carriage trucks. The IMU data was analyzed with the nine features used for rotating machinery systems, including root-mean-square, standard deviation, and kurtosis. For each stage of degradation, the statistical population and median value of each feature were compared against the population and median for no degradation, to monitor feature changes due to ball damage. Correlation analyses revealed an ability of the standard deviation feature to detect statistically significant changes as small as 0.05 micrometers or 0.5 microradians, corresponding to a total damaged surface area of truck balls of less than 0.1 percent.
Preliminary Study on Effects of the Process Parameters on Mechanical Properties in Liquid Holographic Volumetric Additive Manufacturing Process
Authors: James Sagil , Shivakumar Thilakraj
Published: November 2019

The momentum of the additive manufacturing research is on a spurt. Additive manufacturing, also known as 3D printing process has been attracting the attention of the manufacturing community worldwide over the past decade. The 3D printing technology promises significant advances and applications in the area of automobiles, electronics, and medical devices and so on. However, this technology currently suffers from several limitations including large time consumption, need for support structures and limited range of material selection. This prevents its application in mass production. Holographic 3D printing, also referred to as (volumetric additive manufacturing) process is a very recent technique which uses multiple light beams intensified to form a build volume. A photosensitive liquid resin is solidified using the principle of constructive interference. The single light beam is not enough to produce the required intensity to cure the resin. While the combined interference could generate the required energy. The resulting part is printed in a fraction of seconds at once in contrast with the traditional 3D printing technology. This research studies the feasibility of a novel holographic volumetric additive manufacturing with an ultraviolet source of 365 nm as the primary source of energy. This propels the polymeric photochemical reaction between the monomer molecules. Also, experiments are conducted, incorporating various viscosity levels of the photopolymer material to suppress the oxygen dissolution. At the same time to observe the rate of curing of the photopolymer material. Finally, the mechanical properties of the build volume are analyzed.
Effect of Beam Oscillations on Formation of Defects in Electron Beam Welding of Copper Plate
Authors: Jaypuria Sanjib , Chakrabarti Debalay , Pratihar D. K. , Jha M. N.
Published: November 2019

In the present study, electron beam welding bead-on-plate of electrolytic pitched copper (ETP-Cu) plate was carried out to study the behavior of different defects formed in the weld by varying the beam oscillation amplitudes. The defects like spattering, spiking and porosity were considered in this study. Spattering and spiking phenomena were determined with visual inspection and image analysis software, respectively. Porosity measurement was conducted with X-ray tomography. Spattering was found to decrease with the oscillation amplitude up to the optimized value and then, it showed an increasing effect with it. Spatters in the weld also contributed to the pore formation in the weld by the inside pores available in it. Spiking was found to be more dynamic, and not directly related to the oscillation amplitude. But, in general, it was increasing with the increase of amplitude. Spiking was found to have a linear relationship with mean diameter of pores, which implied that a weld with the sharper spikes was more prone to large size root pores in the weld. Mean diameter and volume fraction of the pores were tending to increase with oscillation amplitude; however, there were discontinuities in the trend at the optimized amplitude value. An optimized value of oscillation amplitude was found to be useful for suppressing these defects in the weld. However, a random oscillation amplitude could be more detrimental to the quality of the weld joint.
Friction Surfacing Using Consumable Tools: A Review
Authors: Seidi Ebrahim , Miller Scott F.
Published: November 2019

The friction surfacing technique is a new variation of friction stir welding process for modification of the surface properties of the substrate. There is a growing body of literature dealing with friction surfacing by consumable tool. This is a metallic deposition technique in which a rotating consumable tool deposits material onto a solid substrate. Friction surfacing has many applications in welding, coating, repair of defective components, hard surfacing and corrosion protection. This process does not generate high temperatures; therefore this technique is a suitable coating method capable of joining low melting point alloys. This review paper studies the basic principles and the use of friction surfacing as well as a survey of the latest researches and applications with emphasis on superficial and microstructural characterization, tensile, bending, effects of the different process factors such as axial force, rotation and travel speed, material deposition rate, energy consumption and different tool types. This review shows there are a few investigations dealing with novel tool/workpiece configurations for adding material for purposes other than coating, such as keyhole filling or dissimilar material joining. Also, the possible future directions for development and application of this technique are presented.
A Vision-Based Framework for Enhanced Quality Control in a Smart Manufacturing System
Authors: Yang Zixuan , Teng Huaiyuan , Goldhawk Jeremy , Kovalenko Ilya , Balta Efe C. , Lopez Felipe , Tilbury Dawn , Barton Kira
Published: November 2019

Dimensional metrology is an integral part of quality control in manufacturing systems. Most existing manufacturing systems utilize contact-based metrology, which is time consuming and not flexible to design changes. There have been recent applications of computer vision for performing dimensional metrology in manufacturing systems. Existing computer vision metrology techniques need repeated calibration of the system and are not utilized with data analysis methods to improve decision making. In this work, we propose a robust non-contact computer vision metrology pipeline integrated with Computer Aided Design (CAD) that has the capacity to enable control of smart manufacturing systems. The pipeline uses CAD data to extract nominal dimensions and tolerances. The dimensions are compared to the measured ones, computed using camera images and computer vision algorithms. A quality check module evaluates if the measurements are within admissible bounds and informs a central controller. If a part does not meet a tolerance, the central controller changes a program running on a specific machine to ensure that parts meet the necessary specifications. Results from an implementation of the proposed pipeline on a manufacturing research testbed are given at the end.
Binder Jetting Additive Manufacturing of Ceramics: Comparison of Flowability and Sinterability Between Raw and Granulated Powders
Authors: Du Wenchao , Miao Guanxiong , Liu Lianlian , Pei Zhijian , Ma Chao
Published: November 2019

The objective of this study is to compare three different feedstock powders for the binder jetting process by characterizing their flowability and sinterability. Binder jetting additive manufacturing is a promising technology for fabricating ceramic parts with complex or customized geometries. Granulation is a promising material preparation method due to the potential high sinterability and flowability of the produced powder. However, no study has been made to systematically compare raw and granulated powders in terms of their flowing and sintering behaviors. This paper aims at filling this knowledge gap. Two raw powders (i.e., fine raw powder of 300 nm and coarse raw powder of 70 μm) and one granulated powder from spray freeze drying were compared. Different flowability metrics, including volumetric flow rate, mass flow rate, Hausner ratio, Carr index, and repose angle were measured. Different sinterability metrics, including sintered bulk density, volume shrinkage, and densification ratio were compared for all three powders. Results show that granulated powder achieved comparably high flowability to that of the coarse raw powder and also comparably high sinterability to that of the fine raw powder. Moreover, suitable metrics for the characterization of the sinterability and flowability for these three powders are recommended. This study suggests spray freeze drying produces high-quality feedstock powder for binder jetting process.
Graphene Synthesis on Ultrathin Metal Catalyst Films
Authors: Zhang Kaihao , Tawfick Sameh
Published: November 2019

Graphene synthesis on ultra-thin catalysts can allow the use of graphene-coated metal films in electronic applications. Graphene coated thin films are expected to offer superior mechanical performance owing to the strength of graphene. However, several factors need to be considered to assure the stability of thin films at the high temperatures required for graphene synthesis. In this work, we present a systematic framework for the selection of thin films (< 1 micron thickness) to be used as catalyst for graphene synthesis. We present our progress towards the rapid synthesis of graphene at 1100°C in less than two minutes, thus avoiding solid state dewetting. The quality of the graphene is assessed by Scanning Electron Microscopy, Raman spectroscopy and indentation. It is shown that these films exhibit higher stiffness and resistance to crack propagation.
Determining Feasible Robot Placements in Robotic Cells for Composite Prepreg Sheet Layup
Authors: Malhan Rishi K. , Kabir Ariyan M. , Shah Brual , Centea Timotei , Gupta Satyandra K.
Published: November 2019

High-performance composites are widely used in industry because of specific mechanical properties and lightweighting opportunities. Current automation solutions to manufacturing components from prepreg (pre-impregnated precursor material) sheets are limited. Our previous work has demonstrated the technical feasibility of a robotic cell to automate the sheet layup process. Many decisions are required for the cell to function correctly, and the time necessary to make these decisions must be reduced to utilize the cell effectively. Robot placement with respect to the mold is a significant and complex decision problem. Ensuring that robots can collaborate effectively requires addressing multiple constraints related to the robot workspace, singularity, and velocities. Solving this problem requires developing computationally efficient algorithms to find feasible robot placements in the cell. We describe an approach based on successive solution refinement strategy to identify a cell design that satisfies all constraints related to robot placement.
Error Propagation in Digital Additive Remanufacturing Process Planning
Authors: Alkhateeb Mojahed , Rickli Jeremy L. , Christoforou Nicholas J.
Published: November 2019

A point cloud is a digital representation of a part that consists of a set of data points in space. Typically point clouds are produced by 3D scanners that hover above a part and records points in a large number that represent the external surface of a part. Additive remanufacturing offers a sustainable solution to end-of-use (EoU) core disposal and recovery and requires quantification of part damage or wear that requires reprocessing. This paper proposes an error propagation approach that models the interaction of each step of the additive remanufacturing process. This proposed model is formulated, and the results of the errors generated from the parameters of the scanner and point cloud smoothing are presented. Smoothing is an important step to reduce the noises generated from scanning, knowing the right smoothing factor is important since over smoothing results in dimensional inaccuracies and errors, especially in cores with smaller degrees of damage. It is important to know the error generated from scanning and point cloud smoothing to compensate in the following steps and generate appropriate material deposition paths. Inaccuracies in the 3D model renders can impact the remainder of the additive remanufacturing accuracy, especially because there are multiple steps in the process. Sources of error from smoothing, meshing, slicing, and material deposition are proposed in the error propagation model for additive remanufacturing. Results of efforts to quantify the scanning and smoothing steps within this model are presented.
An Experimental Study of Modulation-Assisted Turning of Ti6Al4V
Authors: Sandoval Juan , Nguyen Dinh , Kwon Patrick , Guo Yang
Published: November 2019

This paper presents an experimental study of modulation-assisted turning of Ti6Al4V. A piezo-actuated turning tool post has been designed and implemented on a CNC toolroom lathe to enable modulation-assisted turning process. Displacement and force measurements were performed to characterize the modulation turning process. Tool wear tests on conventional turning and modulation-assisted turning of Ti6Al4V with uncoated carbide tools were conducted for three different lubrication conditions, including dry, minimum quantity lubrication (MQL), and nano-platelet enhanced MQL (n-MQL). The tool wear study shows that modulation-assisted turning can reduce crater wear but increase the flank wear of the uncoated carbide tool. The cause leading to different performances of modulation-assisted turning on tool wear is discussed.
Rotary Ultrasonic Machining of CFRP Composites: Effects of Carbon Fiber Reinforcement Structure
Authors: Zhang Dongzhe , Wang Hui , Hu Yingbin , Chen Xiaoxu , Cong Weilong , Burks Anthony R.
Published: November 2019

Carbon fiber reinforced plastic (CFRP) composites have been widely used in many applications due to their superior properties of high strength-weight ratio, high stiffness, and high wear resistance. For assembly purposes, hole making is necessary for different applications of CFRP composites. Rotary ultrasonic machining (RUM) has been proposed and investigated for hole making of CFRP composites. Studies on the effects of machining variables, tool variables, workpiece orientation, and cooling conditions on output variables in RUM of CFRP composites have been investigated. The carbon fiber reinforcement structures of CFRP composites also affect the machining performances and part’s quality. However, there is no reported investigation on studying carbon fiber reinforcement structures’ influences in RUM of CFRP composites. Experiments were conducted for this paper to investigate the effects of carbon fiber reinforcement structure on cutting force, torque, and surface roughness. Three major conclusions can be drawn from the results of this experimental investigation. First, CFRP composites with unidirectional structure led to the smallest cutting force and torque, followed by CFRP composites with plain woven structure and twill woven structure. Second, the surface roughness on CFRP composites with plain woven structure was the smallest, followed by the CFRP composites with unidirectional structure and twill woven structure. In addition, CFRP composites with different reinforcement structures have the same tendencies of output variables with different machining variables.
Dimensional Accuracy in PolyJet Printing: A Literature Review
Authors: Thakare Ketan , Wei Xingjian , Pei Zhijian
Published: November 2019

PolyJet printing process is one of the additive manufacturing methods to print parts with high dimensional accuracy. To date, dimensional accuracies of such process have been investigated by a number of studies. This review will summarize those studies, and identify current trends. With respect to methods of measurements used in the reported studies, it is noted that no special preference is given to use of any method. In addition, the effects of four control variables of PolyJet process: part orientation, layer thickness, surface finish type and materials, on dimensional accuracy are noted based on the results of reported studies. There is consistency in results in studies considering control variables of layer thickness, surface finish type and materials. However, the results are inconsistent in studies considering part orientation.
Effect of Tool Condition on Cutting Mechanism in Micromilling
Authors: Varghese Alwin , Kulkarni Vinay , Joshi Suhas S.
Published: November 2019

Cutting mechanism in micromilling is governed by the tool condition along with the machining parameters and workpiece material properties. A rapid tool wear in micromilling often deteriorates the surface quality, which could be due to the occurrence of plowing. The effects of tool condition on the transition in cutting mechanisms from shearing to plowing have not been adequately addressed in micro milling. In this work, we attempt to correlate cutting mechanism with tool conditions, so that their influence on force and surface profiles are investigated. Micro milling experiments are performed to investigate these correlations. A fluctuation parameter has been defined to quantify the fluctuation in force signal. It is evident that as the feed varies from 0.2 μm/teeth to 5 μm/teeth, the fluctuation reduces and similar fluctuations are reflected on the generated surface also. The surfaces corresponding to lower force fluctuations has an Ra value less than 350 nm. As cutting edge radius increases, surface finish decreases. However, with chipping, new sharper cutting edges are formed which may improve the surface finish locally but contribute to the overall variation in the surface profiles.
Simulating the Sequential Honing Process of Engine Cylinder Bore by Modeling Abrasives in Honing Stone
Authors: Zhou Zaoyang , Zhang Xueping , Lv Kunlun , Wu Jun , Yao Zhenqiang , Xi Lifeng
Published: November 2019

Sequential honing process is usually implemented in engine cylinder bore processing to obtain the cross-hatched surface texture with excellent function to balance lubricant storage capacities and supporting performance. Many researches have devoted to correlating honed surface quality of cylinder bore with honing process parameters by means of experiments or simulations. Quite a few efforts have addressed the effect of sequential multiple steps on the surface texture in the honing of engine cylinder bore. However, these researches cannot provide an explicit and analytical methodology to predict honed surface texture efficiently and accurately. This paper presents an analytical and explicit methodology to incorporate a proposed microscale abrasive model into the analytical simulation process of sequential honing. The proposed abrasive model synthetically considers the shape, size, posture, and position of abrasives randomly distributed in honing stone, which is incorporated into honing head motions in terms of rotation, oscillation and feeding. The kinematics of honing head is calculated by space-time discretization to capture the interaction between honing stones and cylinder bore surface. The above procedure acts as each single step for the sequential honing processes. This study investigates the sequential honing of two stages including semi-finish honing and plateau honing at different feeding speeds by applying the abrasive model with different abrasive sizes. The formation of cross-hatched surface texture was successfully achieved sequentially by semi-finish honing and plateaus honing. Then the Abbott-Firestone Curve of the honed surface can be obtained to analyze the influences of abrasive size and honing time of two stages on the surface roughness. Correctness of surface roughness predicted by the model is verified by comparing with a group of experiment measurements in terms of Abbott-Firestone Curve. Most errors of all the predicted Rk roughness family roughness parameters in the two honing stages are less than 15%. Based on the model, simulations are done to analyze the influences of abrasive size and honing duration time of two stages on the surface roughness. The result shows that the larger abrasive used in finish honing leads to the decrease of the material portions Mr1, Mr2 and the increase of the reduced valley depth Rvk. The longer plateau honing duration time is preferred to produce the larger Mr1, Mr2 and the smaller Rvk.