Showing papers on "Process variable published in 2010"

The effect of process parameters on machining of magnesium nano alumina composites through EDM

Abstract: The effects of electrical discharge machining (EDM) parameters on drilled-hole quality such as taper and surface finish are evaluated. Microwave-sintered magnesium nano composites (reinforced with 0.8 and 1.2 wt.% of nano alumina) are used as work materials. Experiments were conducted using Taguchi methodology to ascertain the effects of EDM process parameter. The process parameters such as pulse-on time, pulse-off time, voltage gap, and servo speed were optimized to get better surface finish and reduced taper. ANOVA analyses were carried out to identify the significant factors that affect the hole accuracy and the surface roughness. Confirmation tests were performed on the predicted optimum process parameters. Pulse-on time and the servo speed are identified as major response variables. Micro structural changes and the effects of nano particle reinforcement in the drilled hole were studied through SEM micrographs.

Study of process parameters effect on the filling phase of micro-injection moulding using weld lines as flow markers.

Abstract: Micro-injection moulding (micro-moulding) is a process which enables the mass production of polymer micro-products. In order to produce high-quality injection moulded micro-parts, a crucial aspect to be fully understood and optimised is the filling of the cavity by the molten polymer. As a result, the relationships between the filling pattern and the different process parameter settings have to be established. In this paper, a novel approach based on the use of weld lines as flow markers to trace the development of the flow front during the filling is proposed. The effects on the filling stage of process parameters such as temperature of the melt, temperature of the mould, injection speed and packing pressure have been investigated. An optical coordinate measuring machine has been employed for the investigation. The micro-cavity, which presents micro-features ranging from 600 μm down to 150 μm, has been manufactured by micro-electrodischarge machining. A commercially available polystyrene grade polymer has been moulded using a high-speed injection moulding machine. The design of experiment technique was employed to determine the effect of the process parameters on the filling phase of the micro-cavity. In addition, extensive measuring uncertainty analysis was performed to validate the experimental plan. Results show that the temperature of the mould and the injection speed are the most influencing process parameters during the injection moulding of a micro-component.

Statistical Characterization of Ultrasonic Additive Manufacturing Ti/Al Composites

Abstract: Ultrasonic additive manufacturing (UAM) is an emerging solid-state fabrication process that can be used for layered creation of solid metal structures. In UAM, ultrasonic energy is used to induce plastic deformation and nascent surface formation at the interface between layers of metal foil, thus creating bonding between the layers. UAM is an inherently stochastic process with a number of unknown facets that can affect the bond quality. In order to take advantage of the unique benefits of UAM, it is necessary to understand the relationship between manufacturing parameters (machine settings) and bond quality by quantifying the mechanical strength of UAM builds. This research identifies the optimum combination of processing parameters, including normal force, oscillation amplitude, weld speed, and number of bilayers for the manufacture of commercially pure, grade 1 titanium+1100-O aluminum composites. A multifactorial experiment was designed to study the effect of the above factors on the outcome measures ultimate shear strength and ultimate transverse tensile strength. Generalized linear models were used to study the statistical significance of each factor. For a given factor, the operating levels were selected to cover the full range of machine capabilities. Transverse shear and transverse tensile experiments were conducted to quantify the bond strength of the builds. Optimum levels of each parameter were established based on statistical contrast trend analyses. The results from these analyses indicate that high mechanical strength can be achieved with a process window bounded by a 1500 N normal force, 30 μm oscillation amplitude, about 42 mm/s weld speed, and two bilayers. The effects of each process parameter on bond strength are discussed and explained.

Desirability-Based Multi-Criteria Optimization of HVOF Spray Experiments to Manufacture Fine Structured Wear-Resistant 75Cr3C2-25(NiCr20) Coatings

Abstract: Thermal spraying of fine feedstock powders allow the deposition of cermet coatings with significantly improved characteristics and is currently of great interest in science and industry. However, due to the high surface to volume ratio and the low specific weight, fine particles are not only difficult to spray but also show a poor flowability in the feeding process. In order to process fine powders reliably and to preserve the fine structure of the feedstock material in the final coating morphology, the use of novel thermal spray equipment as well as a thorough selection and optimization of the process parameters are fundamentally required. In this study, HVOF spray experiments have been conducted to manufacture fine structured, wear-resistant cermet coatings using fine 75Cr3C2-25(Ni20Cr) powders (−8 + 2 μm). Statistical design of experiments (DOE) has been utilized to identify the most relevant process parameters with their linear, quadratic and interaction effects using Plackett-Burman, Fractional-Factorial and Central Composite designs to model the deposition efficiency of the process and the majorly important coating properties: roughness, hardness and porosity. The concept of desirability functions and the desirability index have been applied to combine these response variables in order to find a process parameter combination that yields either optimum results for all responses, or at least the best possible compromise. Verification experiments in the so found optimum obtained very satisfying or even excellent results. The coatings featured an average microhardness of 1004 HV 0.1, a roughness Ra = 1.9 μm and a porosity of 1.7%. In addition, a high deposition efficiency of 71% could be obtained.

Optimization of carrot pomace powder incorporation on extruded product quality by response surface methodology

Abstract: Rice and gram flour mix with carrot pomace powder (CPP) was used for the extrudates under study Response surface methodology was used to analyze the effect of die temperature (65–125C), feed rate (25–85 g/s), feed moisture (10–30%, wb) and CPP (15–155%) on extrudate moisture, expansion index, bulk density and sensory characteristics of extrudates Regression equations describing the effect of each variable were obtained Die temperature was observed to be the most effective (P < 005) process variable to affect the selected responses, followed by change in feed moisture and CPP Overall acceptability (OA) of the experimental samples ranged from 34 to 79 for the selected process variables An optimization of process variables using regressed equation was attempted for maximum desirability in responses Optimum incorporation level of CPP was found to be 5%, with OA score of 74 The study demonstrated that an acceptable extruded product can be prepared by CPP incorporation PRACTICAL APPLICATIONS Extrusion is a widely used processing technology in many ready-to-eat cereal-based snacks A lot of work has been done on cereal-based extrusion along with pulse supplementation for improved protein quality The present study also takes its basis from such previous studies Innovative approach in this study involves utilization of a by-product through incorporation of carrot pomace powder (CPP) in pre-extrusion mix Furthermore, a polynomial model is established for each process variable, and CPP incorporation is optimized for the desired quality of extrudates

An analytical energy model for metal foil deposition in ultrasonic consolidation

Abstract: Purpose – Recently, a number of research projects have been focused on an emerging additive manufacturing process, termed ultrasonic consolidation (UC). The purpose of this paper is to present an analytical energy model aimed at investigating the effects of process parameters on bond formation in UC.Design/methodology/approach – In the model, two factors are defined, energy input to the workpiece within a single cycle of ultrasonic vibration (E0) and total energy input to the workpiece (Et), to evaluate to the magnitude of transmitted energy into the workpiece during UC.Findings – It is found that linear weld density, E0 and Et are affected by process parameters in similar manners.Research limitations/implications – The current model is developed based on several simplifying assumptions, and energy dissipation and bond degradation during UC are not considered in the model.Originality/value – The current model gives a useful understanding of the effects of process parameter on the bond formation in UC from...

Process parameter influence to negative tone development process for double patterning

Abstract: Process parameter influence in resist process with negative tone development (NTD) to pattern size (CD), CD uniformity (CUD), and defectivity are studied to estimate the impact for process stability in high volume manufacturing (HVM) of semiconductor devices. Since double exposure process is one of the candidates in contact hole patterning, exposure to exposure delay was studied. There is a possibility to design the off-line system with NTD process, therefore, exposure - PEB delay and PEB - development delay were studied. As basic development parameter studies, development time, developer temperature, developer volume, and rinse time dependency on CD, CDU, and defectivity were investigated.

Researches into Influence of Process Parameters on FDM Parts Precision

Abstract: In the field of RPM( rapid prototyping manufacturing), accuracy and efficiency have become the bottleneck that slows down its development, so how to improve parts precision has been one of the hot research questions. A variety of factors are analyzed which have effect on parts precision , such as extrusion temperature, envelope temperature, extrusion velocity, filling velocity, slicing orientation, slicing thickness, filament-width compensation, and delay time, and then corresponding measures to improve parts precision is presented.

Identification of the optimal (α + β) forging process parameters of Ti–6.5Al–3.5Mo–1.5Zr–0.3Si based on processing-maps

Abstract: The deformation behavior of Ti–6.5Al–3.5Mo–1.5Zr–0.3Si at the deformation temperature of 780–990 °C and the strain rate between 0.001 and 70.0 s −1 was systematically investigated for the identification of the optimal process parameters and the control of microstructure in (α + β) forging process. The processing-maps (P-maps) of the Ti-alloy in the above-mentioned deformation conditions were first constructed based on the experimental data of isothermal compression test. The experimental results show that the flow stress of the alloy is affected by the deformation temperature, strain rate and strain in the deformation process. The flow stress curves generated based on the experiments exhibit a steady-state characteristic and the flow softening behavior at the higher temperature and the lower strain rate. The suitable process parameters in (α + β) forging region are identified to be 855–920 °C, 0.001–0.005 s −1 for the strain less than 0.7. Under this process parameter configuration, the optimum deformation condition is 890 °C, 0.001 s −1 . When the strain is greater than 0.7, the process parameter configurations for superplasticity deformation identified based on P-maps, microstructure observation and verified by the physical experiment of superplasticity deformation are 785–810 °C, 0.001–0.002 s −1 ; 875–925 °C, 0.001–0.005 s −1 and 945–990 °C, 0.001–0.016 s −1 . The optimum (α + β) forging process parameters are 810 °C, 0.001 s −1 ; 900 °C, 0.001 s −1 and 960 °C, 0.001 s −1 .

Process variable transmitter with two-wire process control loop diagnostics

Abstract: A two-wire process variable transmitter (12) for use in an industrial process, including a process variable sensor (14) configured to sense a process variable of a fluid of the industrial process. Output circuitry (36) is configured to provide an output on a two-wire process control loop (18) which is related to the sensed process variable. Loop current measurement circuitry (36) measures a loop current flowing through the two-wire process control loop (18) and terminal voltage measurement circuitry (36) measures a voltage related to a terminal voltage of the process variable transmitter (12). The terminal voltage can be a voltage measured across an electrical connection of the two-wire process variable transmitter (12) to the two-wire process control loop (18). Input circuitry (36) is configured to receive a diagnostic command from the two-wire process control loop (18). A microprocessor (30) configured to perform loop diagnostics on the two-wire process control loop (18) based upon the measured loop current and terminal voltage in response to receipt of a diagnostic command from the two-wire process control loop (18).

Batch control using bang-bang control

Abstract: A method for batch control in a system. The system comprises at least two batch processing sets that share at least one shared equipment. A batch is initiated in each processing set. Process variables from each batch are monitored. At least one process variable from at least one batch are adjusted using bang-bang control to prevent conflicts.

Evaluation of fatigue strength for the reliability of parts produced by direct metal laser sintering (DMLS)

Abstract: This work presents the results of a study to determine the reliability of components manufactured by direct metal laser sintering (DMLS) for fatigue strength. A standard procedure and specimen according to IS 5075-1986 had been used in the experiment. Using Taguchi's experimental design techniques, an orthogonal array of L4 experiments had been developed. Fatigue testing was carried out and analysis of variance (ANOVA) technique was employed to investigate the process parameters in order to identify the main process parameter that affects the performance of the fatigue component. It has been found that scan spacing had more influence on fatigue strength as compared to sintering speed and hatch type. The two-parameter Weibull distribution was adopted to find the reliability of the manufactured components. The Weibull shape parameter and scale parameter was estimated and found approximately by a normal distribution. Micro structural analysis shows that there is a better bonding between the materials when the sintering speed is reduced.

Inertia friction welding process analysis and mechanical properties evaluation of large rotor shaft in marine turbo charger

Abstract: The two aims of this study are first, determining the optimal welding process parameters by using the finite element simulation and second, determining the optimal tempering temperature by evaluating the mechanical properties of friction welded part for manufacturing large rotor shaft. Inertia welding was conducted in order to make the large rotor shaft of turbo charger for low speed marine diesel engine. The rotor shaft is composed of the 310mm diameter disk and the 140mm diameter shaft. Since diameters of disk and shaft are very different, the integration using friction welding reduces manufacturing cost compared with the forming process of which a disk and shaft are forged into one body. Finite element simulation was performed, because inertial welding friction process depended on many process parameters, including axial force, initial revolution speed and energy, amount of upset, and working time. It is expected that this modeling will significantly reduce the number of experimental trials needed when determining the optimal welding parameters. Inertia welding was carried out with optimal process parameter conditions obtained from the simulation results. Welded joint part, made by friction welding, had very poor mechanical properties, and so it required heat treatment. The base material used in the investigation was SFCMV1 (SANYO special steel, high strength low alloy Cr-Mo steel) of 140mm diameter. In the study, heat treatment test carried out quenching (950 °C, 4hr, oil cooling) and tempering (690–720 °C, 6hr, air cooling) for friction welding specimens. The various tests, including microstructure observation, tensile, hardness, and fatigue tests, were conducted to evaluate the mechanical properties under various heat treatment conditions after inertia welding.

Method of energy distribution and consumption control based on melt quality improvement for plastic injection and extrusion processes

Abstract: A method of improving energy consumption and/or melt quality of injection molding or extrusion machine can include controlling energy input to the melt from screw drive and heat sources. One or more sensors can measure a present value of at least one process parameter associated with the melt. A control algorithm can compare the present value of melt with a set value. If the present value deviates from the set value by more than a predetermined amount, the set value of at least one operating parameter can be adjusted. The algorithm can determine energy transferred to melt material from thermal and mechanical sources, and adjust set values to optimize energy consumption or improve melt quality. Process parameters can include melt temperature, melt quality characterized value, prospective throughput or injection cycle time, or prospective energy consumption value. Operating parameters can include barrel heating temperature, screw rotational speed, screw plasticizing back pressure, screw injection speed or screw injection pressure.

Wireless adapter with process diagnostics

Abstract: A process device (12) with diagnostics for use in an industrial process includes a process variable sensor or controller element (22) which is configured to sense or control a process variable of a process fluid of the industrial process. Circuitry (62) is coupled to the process variable sensor or control element (22) and configured to measure or control a process variable of the industrial process. A wireless communication adapter (30) includes wireless communication circuitry configured to communicate in the industrial process. The wireless communication circuitry is further configured to receive a process signal from another process device. Diagnostic circuitry is configured to diagnose operation of the industrial process as a function of the sensed process variable and the received process signal.

Process and apparatus for controlling coating deposition

Abstract: Method and apparatus for controlling a coating deposition process, where at least at one stage of the coating deposition process at least one of the coating precursors comprises a gas, a vapour or an aerosol. The method comprises monitoring ultrafine particles and adjusting at least one process parameter based on the monitoring. The apparatus comprises means (13) for monitoring ultrafine particles and means (14) for adjusting at least one process parameter based on the monitoring.

Effect of Process Parameters on TSV Formation Using Deep Reactive Ion Etching

Abstract: In the development of 3D package, through silicon via (TSV) formation technology by using deep reactive ion etching (DRIE) is one of the key processes. We performed the Bosch process, which consists of sequentially alternating the etch and passivation steps using SF6 with O2 and C4F8 plasma, respectively. We investigated the effect of changing variables on vias: the gas flow time, the ratio of O2 gas, source and bias power, and process time. Each parameter plays a critical role in obtaining a specified via profile. Analysis of via profiles shows that the gas flow time is the most critical process parameter. A high source power accelerated more etchant species fluorine ions toward the silicon wafer and improved their directionality. With O2 gas addition, there is an optimized condition to form the desired vertical interconnection. Overall, the etching rate decreased when the process time was longer. (Received May 12, 2010)

The Effects of Mold Design on the Pore Morphology of Polymers Produced with MuCell ®Technology

Abstract: In this study two molds were designed and used in MuCell technology to generate implants with a porous structure. To arrive the desired pore structure many process parameters were investigated for indicating the effects of process parameters on the pore morphology. This process parameter investigation was performed on each mold respectively, so that the influences of the mold design on the pore morphology have been researched by the same process parameter setting. It was found that the mold design also had effects on the pore structure in MuCell technology. A proper mold design could improve the generated pore structure, such as porosity, pore diameter, and interconnectivity.

Multiple Model and Neural based Adaptive Multi-loop PID Controller for a CSTR Process

Abstract: Multi-loop (De-centralized) Proportional-IntegralDerivative (PID) controllers have been used extensively in process industries due to their simple structure for control of multivariable processes. The objective of this work is to design multiple-model adaptive multi-loop PID strategy (Multiple Model Adaptive-PID) and neural network based multi-loop PID strategy (Neural Net Adaptive-PID) for the control of multivariable system. The first method combines the output of multiple linear PID controllers, each describing process dynamics at a specific level of operation. The global output is an interpolation of the individual multi-loop PID controller outputs weighted based on the current value of the measured process variable. In the second method, neural network is used to calculate the PID controller parameters based on the scheduling variable that corresponds to major shift in the process dynamics. The proposed control schemes are simple in structure with less computational complexity. The effectiveness of the proposed control schemes have been demonstrated on the CSTR process, which exhibits dynamic non-linearity. Keywords—Multiple-model Adaptive PID controller, Multivariable process, CSTR process.

Influence of Surface Tension and Inner Pressure on the Process of Fibre Drawing

Abstract: The present contribution deals with thermofluidynamical features occurring during the drawing of capillaries for microstructured optical fibres. Here, the process stability depends strongly on flow and thermal processes taking place as a preform is heated and drawn in the furnace. This is the case particularly for hollow fibres for which the existence of the inner hole directly depends on material parameters such as the surface tension and the rheological properties and on process parameter such as hole internal pressure and the process temperature. A fluid-mechanics model suggested in the literature that makes use of asymptotic analysis based on small aspect ratio of the micro capillaries, has been revisited and improved recently and the leading-order equations have been then examined in some asymptotic limits by Luzi et al. Starting from the novel class of solutions of the simplified equations of motion the present paper focuses on the effect of both surface tension and internal hole pressure since those are of essential importance during drawing. Thus, comparisons with experimental data are performed, in order to validate the analytical model developed in, which will be briefly presented here. The theoretical model gives very accurate predictions both when the internal hole is pressurized or when no pressure is applied, as long as the temperature does not reach too high values.