bluuebunny/crossref_metadata_2025 huggingface dataset:
Joining Dissimilar Materials Using Friction Stir Scribe Technique
Authors: Upadhyay Piyush , Hovanski Yuri , Jana Saumyadeep , Fifield Leonard S.
Published: September 2016

Development of a robust and cost-effective method of joining dissimilar materials could provide a critical pathway to enable widespread use of multi-material designs and components in mainstream industrial applications. The use of multi-material components such as steel-aluminum and aluminum-polymer would allow design engineers to optimize material utilization based on service requirements and could often lead to weight and cost reductions. However, producing an effective joint between materials with vastly different thermal, microstructural, and deformation responses is highly problematic using conventional joining and/or fastening methods. This is especially challenging in cost sensitive, high volume markets that largely rely on low cost joining solutions. Friction stir scribe technology was developed to meet the demands of joining materials with drastically different properties and melting regimes. The process enables joining of light metals like magnesium and aluminum to high temperature materials like steel and titanium. Viable joints between polymer composites and metal can also be made using this method. This paper will present the state of the art, progress made, and challenges associated with this innovative derivative of friction stir welding in reference to joining dissimilar metals and polymer/metal combinations.
Platform-Dependent Liquid Handling in High-Throughput Biodosimetry Tool
Authors: Bian Dakai , Tsui Jason C. , Repin Mikhail , Garty Guy , Turner Helen , Yao Y. Lawrence , Brenner David J.
Published: September 2016

Due to the need of high speed and efficient biodosimetric assays for triage and therapy in the event of radiological or nuclear attack, a robotically-based automated biodosimetry tool (RABiT) has been developed over the past few years. Adapting the micronucleus assay from filter plates to V-shaped plates presented challenges in the liquid handling, namely cell splashing out of the V-shaped well plate during the cell harvesting, poor cell distribution on the bottom of the image plate during the dispensing, and cell loss from the image plate during the aspiration in the liquid handling process. Experimental and numerical investigations were carried out to better understand the phenomena and mitigate the problems. Surface tension and contact angle among the fluids and the plate wall were accounted for in the discrete and multiphase numerical models. Experimental conditions were optimized based on the numerical results showing the relationship between nozzle speed and amount of splashed liquid, and the relationship between aspiration speed and number of escaped cells. Using these optimized parameters, numbers of micronuclei in binucleated cells showed the same dose dependence in the RABiT-prepared samples as those in the manually prepared ones. Micronucleus assay protocol was fully realized on RABiT.
A Study on Copper Surface Pre-Treatment and Welding With Lasers
Authors: Jiao Junke , Wang Qiang , Wang Feiya , Zhang Wenwu
Published: September 2016

To improve the copper absorption coefficient to lasers, and to realize a high welding quality with a low power laser machine, a black-treating method was proposed in this study. With this method, the reflection coefficient of the copper to lasers with 1064nm wavelength could be reduced from 95% to 15.5%. The experimental study of copper welding with a 500 W fiber laser machine was carried out. The shape, the strength and the micro-hardness of the welding seam with different welding velocity and defocus amount were compared. And, the best welding parameter was obtained. Moreover, the laser welding quality of copper with black-treating and that with graphite coating was compared, and the result showed that the micro-hardness and the strength of the welding seam of copper with black-treating was better than that with graphite coating.
Sustainable Process Planning for Subtractive and Additive Manufacturing Unit Processes
Authors: Linke Barbara , Garcia Destiny , Kaur Gurpreet , Ghadamli Farhad
Published: September 2016

Sustainability in manufacturing implies regarding economic, environmental and social aspects and is of increasing concern to companies and consumers. Traditionally, process planning decisions were mainly based on costs and quality. This paper shows a method to compare different process chains in terms of sustainability indicators. It proposes to include non-value adding steps such as quality control or transport. The method is explained with a case study, where students design, plan, manufacture, and test models for water table experiments. Common additive and subtractive manufacturing processes are applied.
Springback Behavior of Carbon-Fiber-Reinforced Plastic Laminates With Metal Cover Layers in V-Die Bending
Authors: Hahn Marlon , Weddeling Christian , Ben Khalifa Nooman , Shabaninejad Arash
Published: September 2016

The V-die bending of a carbon-fiber reinforced thermoplastic laminate bonded to thin cover layers made of microalloyed steel was investigated. Such hybrid semi-finished products are gaining importance in transport-related lightweight designs. Experiments were conducted for different forming temperatures and dwell times to determine suitable process parameters. The punch radius was varied to evaluate its influence on the springback/negative springback of the fiber-metal laminate (FML). The results, which are in good accordance with a simple analytical model, showed that the solidification of the composite core can compensate for the springback of the metal layers. Micrographs further revealed that the fiber orientation can affect the thickness distribution in the bend area.
In Situ Sensor-Based Monitoring and Computational Fluid Dynamics (CFD) Modeling of Aerosol Jet Printing (AJP) Process
Authors: Salary Roozbeh (Ross) , Lombardi Jack P. , Tootooni M. Samie , Donovan Ryan , Rao Prahalad K. , Poliks Mark D.
Published: September 2016

The aim of this paper is to demonstrate a pathway for in situ real-time monitoring and closed-loop control of aerosol jet printing (AJP) process. To achieve this aim, we instrumented an Optomec AJ-300 aerosol jet printer with multiple temporal and image-based sensors. Experiments were conducted by varying the sheath gas flow rate (ShGFR) and, subsequently, the line morphology was acquired online using a CCD camera mounted coaxial to the nozzle (perpendicular to the platen). To assess the line morphology, we devised a novel digital image processing method that quantifies aspects of line morphology, such as line density, overspray, continuity, edge smoothness, etc. As a result, an optimal process window was established. Next, the underlying aerodynamic phenomena that influence the line morphology are explained based on a two dimensional computational fluid dynamics (2D-CFD) model. Thus, the image processing approach proposed in this work can be used to detect incipient process drifts, while the CFD model will be valuable to suggest the appropriate corrective action to bring the process back in control. We further validate that there is a good agreement between the online and offline results with respect to the quantified morphology of the lines.
Additive Manufacturing of CFRP Composites Using Fused Deposition Modeling: Effects of Process Parameters
Authors: Ning Fuda , Cong Weilong , Jia Zhenyuan , Wang Fuji , Zhang Meng
Published: September 2016

Fused deposition modeling (FDM) is one of the attractive additive manufacturing (AM) technologies for rapid prototyping with complex structures in a short timeframe. Thermoplastics are currently used as common feedstocks to fabricate prototypes in FDM process. However, FDM-fabricated pure thermoplastic parts cannot be used as load-bearing parts in the actual applications due to their limited tensile strength. Such condition could be improved by developing carbon fiber reinforced plastic (CFRP) composites using FDM for potential industrial end users. It is crucial that proper selections of FDM process parameters during fabricating CFRP composite parts could ensure the part quality and properties. However, the effects of FDM process parameters on the tensile properties of CFRP composites have not been explored. In this paper, CFRP composite specimens with 5 wt% carbon fiber content were fabricated using a FDM machine. Tensile testing was conducted to obtain the tensile properties. The effects of process parameters (including infill speed, nozzle temperature, and layer thickness) on the tensile properties of FDM-fabricated CFRP composite parts were investigated.
Effect of Multi-Layer Laser Heating on the Microstructure and Microhardness of Laser Hot-Wire Deposited FV520B Steel
Authors: Wei Shaopeng , Wang Gang , Huang Zilin , Wen Peng , Rong Yiming
Published: September 2016

The mechanical and microstructural properties of FV520B martensitic stainless steel fabricated by laser hot-wire deposition are presented. An investigation based on experimental method was conducted to analyze the development of microstructure and microhardness under multiple laser heating. Multiple layers were cladded on the surface of martensitic stainless steel FV520B by fiber laser. A defect-free and high forming quality coatings were obtained. The microstructure of clad layer and heat affected zone was characterized using an optical microscope, SEM and EBSD. The gradient microhardness from the cladding layer to the substrate was tested. Subsequently, the effect of thermal history under multi-layer laser heating on the microstructure and microhardness was analyzed. Results indicate that the hardening trend in the coating/substrate interface and softening trend in the heat affected zone under laser heating. The tempering effect of the following-layer laser heating facilitates the reprecipitation of the hardening phases in heat affected zone.
Effect of Preheat on Improving Beneficial Surface Residual Stresses During Induction Hardening Process
Authors: Li Zhichao (Charlie) , Freborg Andrew , Ferguson Lynn
Published: September 2016

Applications of the induction hardening process have been gradually increasing in the heat treatment industry due to its energy efficiency, process consistency, and clean environment. Compared to traditional furnace heating and liquid quenching processes, induction hardening is more flexible in terms of process control, and it can offer improved part quality. The commonly modified parameters for the process include the inductor power and frequency, heating time, spray quench delay and quench severity, etc. In this study, a single shot induction hardening process of a cylindrical component made of AISI 4340 is modeled using DANTE®. It is known that the residual stresses in a hardened steel component have a significant effect on high cycle fatigue performance, with higher magnitudes of surface residual compression leading to improved high cycle fatigue life. Induction hardening of steel components produces surface residual compression due to the martensitic transformation of the hardened surface layer, with a high magnitude of compression preferred for improved performance in general. In this paper, a preheat concept is proposed with the induction hardening process for enhanced surface residual compression in the hardened case. Preheating can be implemented using either furnace or low power induction heating, and both processes are modeled using DANTE to demonstrate its effectiveness. With the help of computer modeling, the reasons for the development of residual stresses in an induction hardened part are described, and how the preheat can be used to improve the magnitude of surface residual compression is explained.
Design of a Skin Grafting Methodology for Burn Wound Using an Additive Biomanufacturing System Guided by Hyperspectral Imaging
Authors: Ding Houzhu , Dole Antonio , Tourlomousis Filippos , Chang Robert C.
Published: September 2016

Skin thermal burn wounds are classified by depth and require different levels of medical intervention. In this paper, the authors propose a novel treatment method where hyperspectral imaging (HSI) is applied to measure skin burn wound information that guide an additive biomanufacturing process to print a custom engineered skin graft in three dimensions (3D). Two dimensional principle component analysis (2DPCA) for noise reduction is applied to images captured by HSI in the visible wavelength range from 375 nm to 750 nm. A multivariate regression analysis is used to calculate hemodynamic biomarkers of skin burns, specifically the total hemoglobin concentration (tHb) and oxygen saturation (StO2) of the injured tissue. The biomarker results of the skin burn images are mapped spatially to show the burn wound depth distribution. Based on the biomarker values, the burn area is segmented into different sub areas with different burn degrees. Depth profiles of deep burns which require skin grafting are extracted from the burn distribution map. Next, each profile is processed to generate an additive biomanufacturing toolpath with a prescribed internal tissue scaffold structure. Using the toolpath, a 3D printer processes a custom graft from an alginate polymer hydrogel material. Alginate is chosen as the print material since it can be stretched into aligned fibers to create a porous structure that facilitates oxygen and nutrient uptake. The resultant printed construct demonstrates the feasibility of fabricating patient-specific tissues with custom-geometry grafts for treating clinical burns.
Effects of Process Parameters on Friction Stir Spot Welding of Aluminum Alloy to Advanced High-Strength Steel
Authors: Chen Kai , Liu Xun , Ni Jun
Published: September 2016

Friction stir spot welding (FSSW) process has been successfully applied for joining aluminum alloy 6061 to TRIP 780/800 steel. Effects of tool plunge speed and dwell time on the weld strength were studied through design of experiments and analysis of variance. It is shown that dwell time is a more dominant parameter in affecting the weld strength than plunge speed. Cross sections of weld specimens show the formation of hook with a swirling structure. Higher magnified SEM view with EDS analysis reveals the swirling structure to be composed of alternating thin layers of steel and Al-Fe intermetallic compounds (IMCs). During tensile shear test, cross nugget failure is the only failure mode. Cracks are initiated in the swirling structure at the tensile side of the weld nugget and cleavage feature can be observed on the fractured surface.
A Thermal Model to Predict Tool Temperature in Machining of Ti-6Al-4V Alloy With an Atomization-Based Cutting Fluid Spray System
Authors: Tanveer Asif , Marla Deepak , Kapoor Shiv G.
Published: September 2016

In this study a heat transfer model of machining of Ti-6Al-4V under the application of atomization-based cutting fluid spray coolant is developed to predict the temperature of the cutting tool. Owing to high tool temperature involved in machining of Ti-6Al-4V, the model considers film boiling as the major heat transfer phenomenon. In addition, the design parameters of the spray for effective cooling during machining are derived based on droplet-surface interaction model. Machining experiments are conducted and the temperatures are recorded using the inserted thermocouple technique. The experimental data are compared with the model predictions. The temperature field obtained is comparable to the experimental results, confirming that the model predicts tool temperature during machining with ACF spray cooling satisfactorily.
Interface Characterization of Al-Cu Micro-Laminates Fabricated by Electrically-Assisted Roll Bonding
Authors: Moradi Marzyeh , Ng Man-Kwan , Lee Taekyung , Cao Jian , Picard Yoosuf N.
Published: September 2016

Interface characteristics of Al/Cu micro-laminates fabricated by an Electrically-Assisted Roll Bonding (EARB) process were studied to understand the underlying physical/chemical phenomena that lead to bond strength enhancement when applying electrical current during deformation. Peel tests were conducted for the Al/Cu roll-bonded laminates produced with no current and under 50A and 150A applied current. After peel tests using a micro-tensile machine, the fractured surfaces of both the Al and Cu–sides were examined using scanning electron microscopy (SEM) for fractography and SEM-based energy dispersive (EDS) analysis. Results revealed the strong dependence of the fracture path and its morphology on the strength of the bond, which is influenced by various phenomena occurring at the interface during EARB, such as microextrusion through surface micro-cracks, possible formation of intermetallic components and thermal softening during simultaneous application of strain and high current density.
Automating Asset Knowledge With MTConnect
Authors: Venkatesh Sid , Ly Sidney , Manning Martin , Michaloski John , Proctor Fred
Published: September 2016

In order to maximize assets, manufacturers should use real-time knowledge garnered from ongoing and continuous collection and evaluation of factory-floor machine status data. In discrete parts manufacturing, factory machine monitoring has been difficult, due primarily to closed, proprietary automation equipment that make integration difficult. Recently, there has been a push in applying the data acquisition concepts of MTConnect to the real-time acquisition of machine status data. MTConnect is an open, free specification aimed at overcoming the “Islands of Automation” dilemma on the shop floor. With automated asset analysis, manufacturers can improve production to become lean, efficient, and effective. The focus of this paper will be on the deployment of MTConnect to collect real-time machine status to automate asset management. In addition, we will leverage the ISO 22400 standard, which defines an asset and quantifies asset performance metrics. In conjunction with these goals, the deployment of MTConnect in a large aerospace manufacturing facility will be studied with emphasis on asset management and understanding the impact of machine Overall Equipment Effectiveness (OEE) on manufacturing.
Implementing the ISO 15746 Standard for Chemical Process Optimization
Authors: Shao Guodong , Denno Peter , Jones Albert , Lu Yan
Published: September 2016

This paper proposes an approach to integrating advanced process control solutions with optimization (APC-O) solutions, within any factory, to enable more efficient production processes. Currently, vendors who provide the software applications that implement control solutions are isolated and relatively independent. Each such solution is designed to implement a specific task such as control, simulation, and optimization — and only that task. It is not uncommon for vendors to use different mathematical formalisms and modeling tools that produce different data representations and formats. Moreover, instead of being modeled uniformly only once, the same knowledge is often modeled multiple times — each time using a different, specialized abstraction. As a result, it is extremely difficult to integrate optimization with advanced process control.

We believe that a recent standard, International Organization for Standardization (ISO) 15746, describes a data model that can facilitate that integration. In this paper, we demonstrate a novel method of integrating advanced process control using ISO 15746 with numerical optimization. The demonstration is based on a chemical-process-optimization problem, which resides at level 2 of the International Society of Automation (ISA) 95 architecture. The inputs to that optimization problem, which are captured in the ISO 15746 data model, come in two forms: goals from level 3 and feedback from level 1. We map these inputs, using this data model, to a population of a meta-model of the optimization problem for a chemical process. Serialization of the metamodel population provides input to a numerical optimization code of the optimization problem. The results of this integrated process, which is automated, provide the solution to the originally selected, level 2 optimization problem.
Predicting the Force Needed to Create a Compression Seal in an Ultra-Thin Elastoviscoplastic Membrane
Authors: McNeff Patrick S. , Paul Brian K.
Published: September 2016

In this paper, a finite element model is developed, and experimentally validated, for predicting the force required to produce a compression seal between a polycarbonate sealing boss and a 25 μm thick elastoviscoplastic hemodialysis membrane. This work leverages previous efforts to determine the conditions for hermetic sealing in a microchannel hemodialyser fabricated using hot-embossed polycarbonate microchannel laminae containing sealing boss features. Methods are developed for mechanically characterizing the thin elastoviscoplastic hemodialysis membrane. Experimental data for assessing the depth of penetration into the membrane as a function of force show an R2 value of 0.85 showing good repeatability. The average percent error was found to be −8.0% with a range between −21.9% and 4.4% error in the strain region of interest.
Solutions for Sustainable Machining
Authors: Uhlmann Eckart , Peukert Bernd , Thom Simon , Prasol Lukas , Fürstmann Paul , Sammler Fiona , Richarz Sebastian
Published: September 2016

The manufacturing industry contributes over 19% to the world’s greenhouse gas emissions [1, 3] and 31% of the total energy consumed annually in the United States of America [2, 3]. There is therefore an increasing demand for sustainable solutions for the production technology industry. At the Technische Universitaet (TU) Berlin, Germany, a collaborative research center (CRC) is focusing on new solutions for the sustainable machining of high performance alloys, with developments from machine tools frames to cutting tool technology being undertaken. An innovative machine tool concept with a modular frame, which allows a high level of flexibility, has been developed. Furthermore, add-on upgrading systems for older machine tools, which are particularly relevant for developing countries, have been developed. These systems allow the accuracy of outdated machine tools to be increased, thus making the machine tools comparable to modern systems. Finally the cutting process also requires solutions for dry machining, as the use of cooling lubricant is environmentally damaging and a significant cost contributor in machining processes. Two solutions are being developed at the TU Berlin: an internally cooled cutting tool and a heating concept for ceramic tools to allow dry machining of high temperature alloys, for example for the aerospace industry.
The Leidenfrost Effect at the Nanoscale
Authors: Cordeiro Jhonatam , Desai Salil
Published: September 2016

Nanotechnology has been presenting successful applications in several field, such as electronics, medicine, energy and new materials. However, the high cost of investment in facilities, equipment and materials as well as the lack of some experimental analysis at the nanoscale can restrain research in nanotechnology. The implementation of accurate computer models can alleviate this problem. This work investigates the Leidenfrost effect at the nanoscale using molecular dynamics simulation. Models of water droplets with diameters of 4nm and 10nm are simulated over gold and silicon substrates. To induce the Leidenfrost effect, droplets at 293K were deposited on the substrates at 373K. As a baseline, simulations were run with substrates at room temperature. Results show that for substrates at 293K, the 4nm droplet has higher position variability than the 10nm droplets. For substrates at 373K, the 4nm droplets have higher velocities than the 10nm droplets. The wettability of the substrate also influences the Leidenfrost. Droplets over the gold substrate which has hydrophobic characteristics have higher velocities as compared to droplets over silicon that has a hydrophilic behavior. Moreover, the Leidenfrost effect was observed at the boiling temperature of water (373K) which is a significantly lower temperature than reported in previous experiments at the microscale.
Anisotropy Effect on Cutting Monocrystal Sapphire by Micro-Laser Assisted Machining Technique
Authors: Mohammadi Hossein , Patten John A.
Published: September 2016

Machining of hard and brittle materials such as ceramics and semiconductors has been a challenge for many years. They have many applications in optics, MEMS and electronic industries due to their many desirable properties, such as being light weight, strong, and hard. Achieving good surface finish, avoiding surface and subsurface damage and at the same time achieving a high material removal rate are extremely challenging for these materials. Materials such as single crystal silicon and sapphire have a crystal orientation or anisotropy effect which makes their machining even more difficult. Because of this characteristic, their behavior is directional and they have different fracture toughness for each direction. In past works in our research group, it has been demonstrated that machining of brittle materials in ductile regime is possible due to the high pressure phase transformation (HPPT) occurring in the material caused by the high compressive and shear stresses induced by a single point diamond tool tip. In the current study scratch tests were performed on the monocrystal sapphire in four different perpendicular directions and to further augment the process, traditional cutting is coupled with a laser to heat and soften the material to either enhance the ductility, resulting in a deeper cut, or reducing brittleness leading to decreased fracture damage. Results of scratch tests, with and without laser heating, for different cutting loads have been compared. The effect of laser heating was studied by analyzing the image of cuts and verifying the depth of cuts which were made using varying laser power during the process. Microscopic images and three-dimensional profiles of the cuts taken by using a white light interferometer were investigated.
Machine Condition Detection for Milling Operations Using Low Cost Ambient Sensors
Authors: Narayanan Anantha , Kanyuck Alec , Gupta Satyandra K. , Rachuri Sudarsan
Published: September 2016

In recent years, sensor technology and data mining capabilities have advanced greatly, allowing advanced manufacturing enterprises to closely monitor their manufacturing operations. At the same time, a thriving market has developed for low cost consumer level sensors and processors. A proliferation of low cost sensing hardware, combined with the availability of free and open source software for performing data analytics, provides a new opportunity for smaller manufacturers. Yet, these tools have not been investigated deeply in the manufacturing world. In this work, we use a combination of low cost sensing hardware and free and open source software to monitor a milling machine operation. We demonstrate that the data collected from these sensors can be used to reliably determine the operating condition of the machine. These techniques will be very valuable for small manufacturers, to determine key factors such as machine utilization, or to detect catastrophic failures early during machining.
Effects of Die Size on Pellet Quality for Cellulosic Ethanol Manufacturing
Authors: Zhang Qi , Heng Lin , Zhou Jiping , Li Zhichao
Published: September 2016

Cellulosic ethanol can be used as a sustainable alternative transportation fuel. A major obstacle to restrict large-scale cellulosic ethanol manufacturing is low bulk density of cellulosic biomass that increases costs during transportation, storage and application of biomass. Biomass pelleting can significantly increase density of biomass. Pellets with high density can be handled, transported, stored and utilized easily. Ring-die pelleting, a traditional pelleting method, is widely used in biomass densification industry. This paper reported an experimental study to compare pellet quality (such as equilibrium moisture content, density, and durability) and microstructure of corn stover processed by a ring-die pellet mill with three different die sizes. Results showed that round and bigger die (32 mm instead of 9 mm) results in higher pellet density, durability, and lower equilibrium moisture content.
Evaluating Rigid and Semi-Flexible Fiber Orientation Evolution Models in Simple Flows
Authors: Lambert Gregory M. , Baird Donald G.
Published: September 2016

As American vehicle fuel efficiency requirements have become more stringent due to the CAFE standards, the auto industry has turned to fiber reinforced polymer composites as replacements for metal parts to reduce weight while simultaneously maintaining established safety standards. Furthermore, these composites may be easily processed using established techniques such as injection molding and compression molding. The mechanical properties of these composites are dependent on, among other variables, the orientation of the fibers within the part.

Several models have been proposed to correlate fiber orientation with the kinematics of the polymer matrix during processing, each using various strategies to account for fiber interactions and fiber flexing. However, these all require the use of empirical fitting parameters. Previous work has obtained these parameters by fitting to orientation data at a specific location in an injection-molded part. This ties the parameters to the specific mold design used. Obtaining empirical parameters is not a trivial undertaking and adds significant time to the entire mold design process. Considering that new parameters must be obtained any time some aspect of the part or mold is changed, an alternative technique that obtains model parameters independent of the mold design could be advantageous.

This paper continues work looking to obtain empirical parameters from rheological tests. During processing, the fiberpolymer suspension is subjected to a complex flow with both shear and extensional behavior. Rather than use a complex flow, this study seeks to isolate and compare the effects of shear and extension on two orientation models. To this end, simple shear and planar extension are employed and the evolution of orientation from a planar random initial condition is tracked as a function of strain.

Simple shear was imparted using a sliding plate rheometer designed and fabricated in-house. A novel rheometer tool was developed and fabricated in-house to impart planar extension using a lubricated squeeze flow technique, where a low viscosity Newtonian lubricant is applied to the solid boundaries to minimize the effect of shearing due to the no-slip boundary condition. The Folgar-Tucker model with a strain reduction factor is used as a rigid fiber model and compared against a Bead-Rod model (a semi-flexible model) proposed by Ortman. Both models are capable of predicting the data, with the Bead-Rod model performing slightly better. Orientation occurs at a much faster rate under startup of planar extension, and also attains a much higher degree of flow alignment when compared with startup of steady shear.
A Method to Optimize Value Recovery From End-of-Life Products
Authors: Cong Liang , Zhao Fu , Sutherland John W.
Published: September 2016

Recovering valuable materials and components from end-of-life (EOL) products is an important means to mitigate the risk of disruption in the supply of virgin, critical materials. The economic viability of value recovery from EOL products is greatly affected by the dismantling process plan, i.e., the processes and the sequence used to recover components and materials. This paper presents an approach to find the optimal EOL strategy, which includes a method for automatic generation of disassembly model and making decisions on the best disassembly sequence, level and EOL options of components/parts. The approach also proposes to identify bottlenecks; degree of automation and destructive disassembly (dismantling) are considered as schemes to attenuate bottlenecks. The ultimate goal of the work is to provide recyclers with process plans to maximize their economic return and to help designers to evaluate product recyclability. A hard disk drive is used as a case study to demonstrate the effectiveness of the approach.
Solution and Aging Treatments of Inconel 718/TiC Nanocomposite From Selective Laser Melting
Authors: Wang Yachao , Shi Jing , Lu Shiqiang , Wang Yun
Published: September 2016

Fabricating metal matrix composites (MMCs) through laser assisted additive manufacturing (LAAM) has attracted much attention in recent years. This is because the traditional metal components produced by LAAM are usually inferior to the counterparts produced by conventional manufacturing processes, reflected by porosity, lower density, and thus poorer mechanical properties and service performance. Adding reinforcements to metal matrix in LAAM process can alleviate the challenge. Also, for components produced by LAAM processes, post treatment is often required to further strengthen the material, reduce residual stress, or clean off surface for dimensional accuracy. However, research regarding how post treatment affects the microstructure and mechanical properties of LAAM-produced MMCs is still very rare in literature.

In this study, a nano-TiC reinforced Inconel 718 composite is prepared using selective laser melting (SLM) technique. Various post heat treatment processes have been adopted to investigate their effect on final product properties. The motivation is that Inconel 718 is a Ni-based superalloy, whose full potential is explored in heat treatment after manufacturing processes. A composite with 0.5 wt.% nano-TiC addition is prepared. Three levels of solution temperatures at 940, 980, and 1020 °C (for 1 hr) or one level of annealing temperature at 1100 °C (for 1 hr) are adopted for the treatment, combined with the standard two-step aging (720 °C, 8 h, furnace cooling + 620 °C, 8 h, air cooling) on both the MMC and unreinforced Inconel 718 materials. Scanning electron microscopy (SEM) observation is conducted to analyze the microstructure of the composite and understand the reinforcing mechanism. Tensile tests are conducted to evaluate the tensile properties. It is discovered that compared with the pure Inconel 718 by SLM, the Inconel 718-TiC MMC exhibits improved ultimate tensile strength for both as-built and solution/annealing treated conditions. Microscopy observation shows that the dendritic structures of Inconel 718 is remarkably refined by the TiC particles in as-built samples, and grain coarsening is largely inhibited by the TiC particles for solution/annealing treated samples. For both reinforced and unreinforced Inconel 718, dissolving of Laves phase and precipitation of δ phase is observed, but annealing at 1100 °C is not favorable for the formation of δ phase. Aging treatment significantly increases the UTS values for both type of material. Moreover, the strengthening effect of added nano particles becomes less significant in the aged condition, due to the precipitation of γ′ and γ″. Future work includes the process parameter optimization, and further evaluation of other mechanical properties.
Identifying Uncertainty in Laser Powder Bed Fusion Models
Authors: Lopez Felipe , Witherell Paul , Lane Brandon
Published: September 2016

A limitation frequently encountered in additive manufacturing (AM) models is a lack of indication about their precision and accuracy. Often overlooked, information on model uncertainty is required for validation of AM models, qualification of AM-produced parts, and uncertainty management. This paper presents a discussion on the origin and propagation of uncertainty in Laser Powder Bed Fusion (L-PBF) models. Four sources of uncertainty are identified: modeling assumptions, unknown simulation parameters, numerical approximations, and measurement error in calibration data. Techniques to quantify uncertainty in each source are presented briefly, along with estimation algorithms to diminish prediction uncertainty with the incorporation of online measurements. The methods are illustrated with a case study based on a transient, stochastic thermal model designed for melt pool width predictions. Model uncertainty is quantified for single track experiments and the effect of online estimation in overhanging structures is studied via simulation. The application of these concepts to estimation and control of the L-PBF process is suggested.
Friction Stir Welding of Aluminum Alloy 1100 and Titanium-Al Alloy
Authors: Dhindaw B. K. , De P. S. , Jayashree Priyadarshini
Published: September 2016

A intercalating joint between Al and Ti alloy is friction stir welded using a high speed steel tool. The material mixing occurs mainly in the shoulder region while the pin region shows nominal mixing. Microscopy and hardness experiments indicate sporadic formation of intermetallic compounds. The joint region near the shoulder and to some extent below it shows increase in hardness compared to the base Ti alloy.
The Effect of Magnetic Abrasive Finishing on the Needle Inner Friction Force and Biopsy Length
Authors: Li Weisi , Lin Wei-Chen , Nteziyaremye Valens , Yamaguchi Hitomi , Guo Dongming , Shih Albert
Published: September 2016

Increasing biopsy length could reduce the false negative rate in prostate biopsy diagnosis. In this paper, the effect of magnetic abrasive finishing (MAF) of needle inner surface on inner friction force and biopsy length was investigated. The test was conducted using the tissue-mimicking material polyvinyl chloride (PVC) and chicken breast. The inner friction forces of MAF-polished and unpolished needles were measured. In the PVC phantom, the smoothly polished needle had lowest inner friction force (0.0024 N/mm) and longest biopsy sample (34.3 mm). Although the roughly polished needle had a smoother surface than the unpolished needle, the significance of the effects on the biopsy performance due to the slight improvement of the needle surface was not observed. The biopsy tests with chicken breast tissue showed the trends similar to the case with PVC phantom. The smoothly polished needle had the smallest inner friction force (0.024 N/mm) and the longest biopsy sample (9.6 mm). These results showed that lowering the friction force between the needle and tissue facilitates the sliding of tissue along the needle, leading to a long biopsy sample. MAF can reduce the friction at the needle-tissue interface and obtaining longer biopsy samples.
Increasing the Fracture Strength and Strain of Bulk Metallic Glasses by Ultrasonic Nano-Crystal Surface Modification
Authors: Ma Chi , Dong Yalin , Ye Chang
Published: September 2016

A novel surface technique, ultrasonic nano-crystal surface modification (UNSM), was used to process BMGs (Bulk Metallic Glasses) to improve the fracture strength and strain. It has been found that the fracture strength and strain are increased by 14.6% and 15.3% respectively after UNSM. In addition, micro-defects (voids and cracks) are found at the surface layer of UNSM-treated specimen after fracture, while there are fewer micro-defects observed in the untreated sample. We attribute the improvement of fracture stress and strain to two mechanisms. First, the excess free volume generated in BMGs by UNSM helps the nucleation of shear bands and the redistribution of the localized deformation. Second, the compressive residual stress generate by UNSM can slow down crack propagation. Both mechanisms lead to the improvement of BMGs fracture strength and strain.
Fast Generation of Planar Micro-Structured Surfaces by Elliptical Vibration Texturing
Authors: Yang Yang , Guo Ping
Published: September 2016

Micro-structured surfaces have extensive applications in a wide array of fields, due to their improved functional performance. Existing manufacturing methods for these surfaces fall short of efficiency for volume production or are only applicable to a specific class of materials. In this paper, an innovative and highly-efficient machining method, elliptical vibration texturing (EVT), is proposed for rapid generation of micro-dimples on planar engineered surfaces. The cutting tool of the EVT process vibrates along an elliptical trajectory. The elliptical vibrations, when coupled with a high cutting velocity, impose micro-dimples onto workpiece surfaces while machining. The high productivity is achieved by adopting a newly designed tertiary motion generator which is able to deliver required elliptical vibrations at an ultrasonic frequency. The shape and distribution of the generated dimple patterns have been theoretically analyzed and predicted by a proposed simulation model. Preliminary texturing results using aluminum and brass as workpieces are given to validate the process principle and simulation model.
Mechanical Ruling of Diffraction Grating: Part II — Experimental Investigation and Numerical Simulation
Authors: Wang Qinghua , Shen Ninggang , Zhang Baoqing , Ding Hongtao
Published: September 2016

This is Part II of a two-part series study on mechanical ruling of diffraction grating. In Part I, effects of the Al film preparation process on the film attributes were investigated in terms of surface morphology, microstructure and mechanical properties using SEM, XRD, nanoindentation and scratch tests. In this part, mechanical ruling experiments were carried out on the prepared Al films with various thicknesses. The effect of ruling loads on the groove geometry were investigated. The tool wear after the mechanical ruling tests was inspected. A three-dimensional thermomechanical coupled finite element (FE) model was developed to predict the deformation and temperature fields during mechanical ruling. The strain gradient plasticity model was used in the FE analysis to model the size effect during the process. The multi-pass effect on the variation of groove geometry was predicted and analyzed with the FE model under different loading conditions.
Surface Variation Modeling by Fusing Surface Measurement Data With Multiple Manufacturing Process Variables
Authors: Ren Jie , Wang Hui
Published: September 2016

Controlling surface shape variations plays a key role in high-precision manufacturing. Most manufacturing plants rely on a number of multi-resolution measurements on manufactured surfaces to evaluate surface shapes and resultant quality. Conventional research on surface shape modeling focused on interpolation and extrapolation of spatial data using sampled measurements based on presumed spatial relationship over entire surface locations. However, the prediction accuracy is heavily restricted by the density of sampled measurements, preventing cost-effective evaluation of surface shape in high precision. New opportunities emerge for cost-effective high-precision surface manufacturing when the industry begins to extensively collect in-plant process information. This paper explores the opportunity by investigating strategies for fusing surface measurement data with multiple process variables. The fusion is achieved by characterizing the relationships between surface height and process variables using (1) linear regression based co-Kriging and (2) fuzzy if-then rules as well as considering spatial correlations. Under (3) Bayesian sequential updating frameworks, a generic surface variation model is updated sequentially using different process information. Case studies are conducted for comparisons and demonstrate the advantages of the fuzzy inference based spatial model.
A System Design for Computer-Aided Manufacturing Shared, Interactive Process Setup Sheets
Authors: Hedrick R. , Urbanic R. J. , Novak Ashley
Published: September 2016

Computer-aided manufacturing (CAM) software is used to develop a process plan, which consists of an operations list, tool paths, tooling, process parameters, and depending on the system, material handling operations. Upon completing the development of a process plan, setup sheets are generated for the personnel involved in the setup, production, testing, and product validation activities for a product. Typically, this documentation is in a hardcopy format, or is a static electronic document, and the direction of the communication is unidirectional — from the process planner to the support personnel. With the ubiquitous communications tools available to individuals today, a more sophisticated approach should be taken to transmit, store, and communicate changes to and from the shop floor. Presently, standard setup documentation consists of the project information utilized for the developed process plan. Pictures such as screen captures of the tool path, virtual verification images, and physical elements such as specialty tools may be included. However, modifications are made continuously to improve the cycle time, quality, or to adjust for other product or process changes. This research focuses on the development of interactive setup sheets that utilize existing desktop CAD/CAM software and mobile technologies, with the potential for leveraging the advantages of manufacturing cloud computing. Videos, links to additional documentation, and the ability to edit a subset of process parameters such as a tool diameter are incorporated. The operator is able to physically change tools or other key process setup information, and then send the information to the CAM system in order to regenerate the updated tool paths and documentation. Complementing the flexible, agile, and reconfigurable paradigms is the communication flexibility provided by fast wireless networks along with, cloud computing resources that can accessed with mobile devices, which are ubiquitous in today’s society. This technology that has not yet been heavily employed in the manufacturing environment, and research leveraging these new tools need to be explored.
An Experimental Study on the Effect of Compression Force Uniformity in Electrosurgical Tissue Welding
Authors: Li Xiaoran , Borduin Russell , Chen Roland , Li Wei
Published: September 2016

Bipolar forceps are a type of electrosurgical device (ESD) widely used for tissue welding in modern surgeries. ESDs have many advantages over traditional surgical tools including reduced blood loss, improved efficiency and lower surgeon fatigue. However, these devices suffer from tissue sticking and damage due to overheating which leads to poor tissue joint quality. The problem is potentially caused by uneven power distribution due to non-uniform compression applied by the bipolar forceps. In this study, the effect of compression force uniformity was investigated with an experimental setup to achieve a uniform and consistent compression force at the jaws of bipolar forceps. Comparative tissue welding experiments were conducted under both uniform and non-uniform compression force conditions with tissue mimicking material. In situ welding process parameters including compression force, electrical voltage, and current were collected and analyzed to understand the effect of compression force uniformity. Comparing the uniform to non-uniform compression force cases, the results indicate that tissue impedance is lower due to increased tissue contact area; the electrical power is initially higher during the first few milliseconds, but becomes lower for the rest of the welding process recorded. The experimental device developed in this study provides an important platform to understand the difference of tissue welding process under uniform and non-uniform compression force conditions.