In Situ Functional Monitoring of Aerosol Jet-Printed Electronic Devices Using a Combined Sparse Representation-Based Classification (SRC) Approach

2018 ◽  
Author(s):  
Roozbeh (Ross) Salary ◽  
Jack P. Lombardi ◽  
Darshana L. Weerawarne ◽  
M. Samie Tootooni ◽  
Prahalada K. Rao ◽  
...  
Keyword(s):  
Sparse Representation ◽  
Functional Properties ◽  
Process Parameters ◽  
Flow Rate ◽  
Gas Flow ◽  
Electronic Devices ◽  
In Situ Monitoring ◽  
Gas Flow Rate ◽  
Aerosol Jet Printing

The goal of this work is in situ monitoring of the functional properties of aerosol jet-printed electronic devices. In pursuit of this goal, the objective is to develop a multiple-input, single-output (MISO) machine learning model to estimate the device functional properties in a near real-time fashion as a function of process parameters as well as 2D/3D features of line morphology. The aim is to use the MISO model for in situ estimation and thus, monitoring of line/device resistance in aerosol jet printing (AJP) process. To realize this objective, silver nanoparticle structures are printed by varying three process parameters: (i) sheath gas flow rate (ShGFR), (ii) exhaust gas flow rate (EGFR), and (iii) print speed (PS). Subsequently, line morphology is captured in situ using a high-resolution charge-coupled device (CCD) camera, mounted coaxial to the nozzle. Besides, utilizing 2D/3D quantifiers (introduced in the authors’ previous publications), the line morphology is further quantified, and the extracted features (e.g., line width, overspray, cross-sectional area, etc.) are fed as inputs to a novel sparse representation-based classification (SRC) model. The four-point probe method is used for measurement of resistance, and definition of a priori classification labels. The outcome of this research paves the way for future control of device functional properties in AJP process.

scholarly journals A Sparse Representation Classification Approach for Near Real-Time, Physics-Based Functional Monitoring of Aerosol Jet-Fabricated Electronics

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Roozbeh (Ross) Salary ◽  
Jack P. Lombardi ◽  
Darshana L. Weerawarne ◽  
M. Samie Tootooni ◽  
Prahalada K. Rao ◽  
...  
Keyword(s):  
Sparse Representation ◽  
Real Time ◽  
Functional Properties ◽  
Printed Electronics ◽  
Imaging System ◽  
Monitoring And Control ◽  
Wide Range ◽  
Sparse Representation Classification ◽  
Aerosol Jet Printing

Abstract Aerosol jet printing (AJP) is a direct-write additive manufacturing (AM) method, emerging as the process of choice for the fabrication of a broad spectrum of electronics, such as sensors, transistors, and optoelectronic devices. However, AJP is a highly complex process, prone to intrinsic gradual drifts. Consequently, real-time process monitoring and control in AJP is a bourgeoning need. The goal of this work is to establish an integrated, smart platform for in situ and real-time monitoring of the functional properties of AJ-printed electronics. In pursuit of this goal, the objective is to forward a multiple-input, single-output (MISO) intelligent learning model—based on sparse representation classification (SRC)—to estimate the functional properties (e.g., resistance) in situ as well as in real-time. The aim is to classify the resistance of printed electronic traces (lines) as a function of AJP process parameters and the trace morphology characteristics (e.g., line width, thickness, and cross-sectional area (CSA)). To realize this objective, line morphology is captured using a series of images, acquired: (i) in situ via an integrated high-resolution imaging system and (ii) in real-time via the AJP standard process monitor camera. Utilizing image processing algorithms developed in-house, a wide range of 2D and 3D morphology features are extracted, constituting the primary source of data for the training, validation, and testing of the SRC model. The four-point probe method (also known as Kelvin sensing) is used to measure the resistance of the deposited traces and as a result, to define a priori class labels. The results of this study exhibited that using the presented approach, the resistance (and potentially, other functional properties) of printed electronics can be estimated both in situ and in real-time with an accuracy of ≥ 90%.

scholarly journals The Effect of Process Parameters on the Microstructure and Mechanical Properties of AW5083 Aluminum Laser Weld Joints

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1443 ◽  
Author(s):  
Maroš Vyskoč ◽  
Miroslav Sahul ◽  
Mária Dománková ◽  
Peter Jurči ◽  
Martin Sahul ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Process Parameters ◽  
Flow Rate ◽  
Weld Joint ◽  
Gas Flow ◽  
Filler Wire ◽  
Shielding Gas ◽  
Gas Flow Rate ◽  
Weld Joints

In this article, the effect of process parameters on the microstructure and mechanical properties of AW5083 aluminum alloy weld joints welded by a disk laser were studied. Butt welds were produced using 5087 (AlMg4.5MnZr) filler wire, with a diameter of 1.2 mm, and were protected from the ambient atmosphere by a mixture of argon and 30 vol.% of helium (Aluline He30). The widest weld joint (4.69 mm) and the highest tensile strength (309 MPa) were observed when a 30 L/min shielding gas flow rate was used. Conversely, the narrowest weld joint (4.15 mm) and the lowest tensile strength (160 MPa) were found when no shielding gas was used. The lowest average microhardness (55.4 HV0.1) was recorded when a 30 L/min shielding gas flow rate was used. The highest average microhardness (63.9 HV0.1) was observed when no shielding gas was used. In addition to the intermetallic compounds, β-Al3Mg2 and γ-Al12Mg17, in the inter-dendritic areas of the fusion zone (FZ), Al49Mg32, which has an irregular shape, was recorded. The application of the filler wire, which contains zirconium, resulted in grain refinement in the fusion zone. The protected weld joint was characterized by a ductile fracture in the base material (BM). A brittle fracture of the unshielded weld joint was caused by the presence of Al2O3 particles. The research results show that we achieved the optimal welding parameters, because no cracks and pores were present in the shielded weld metal (WM).

scholarly journals Application of Taguchi technique to optimize the gma welding parameters and study of fracture mode characterization of AISI 304H welded joints

2018 ◽  
Vol 9 (1) ◽  
pp. 9-16
Author(s):  
S. A. Rizvi
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Process Parameters ◽  
Flow Rate ◽  
Fracture Mode ◽  
Welded Joints ◽  
Gas Flow ◽  
Welding Parameters ◽  
Taguchi Technique ◽  
Gas Flow Rate

This research article is focusing on the optimization of different welding process parameters which affect the weldability of stainless steel (AISI) 304H, Taguchi technique was used to optimize the welding parameters and the fracture mode characterization was studied. A number of experiments have been conducted. L9 orthogonal array (OA) (3×3) was applied. Analysis of variance ( ANOVA) and signal to noise ratio (SNR) was applied to determine the effect of different welding parameters such as welding current, wire feed speed and gas flow rate on mechanical, microstructure properties of SS304H. Ultimate tensile strength (UTS), toughness, microhardness (VHN), and mode of fracture was examined to determine weldability of AISI 304H and it was observed from results that welding voltage has major impact whereas gas flow rate has minor impact on ultimate tensile strength of the welded joints. Optimum process parameters were found to be 23 V, 350 IPM travel speed of wire and 15 l/min gas flow rate for tensile strength and mode of fracture was ductile fracture for tensile test specimen.

Computational Fluid Dynamics Modeling and Online Monitoring of Aerosol Jet Printing Process

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Roozbeh (Ross) Salary ◽  
Jack P. Lombardi ◽  
M. Samie Tootooni ◽  
Ryan Donovan ◽  
Prahalad K. Rao ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Rate ◽  
Gas Flow ◽  
Online Monitoring ◽  
Print Quality ◽  
Cfd Model ◽  
Gas Flow Rate ◽  
Jet Printing ◽  
Aerosol Jet Printing

The objectives of this paper in the context of aerosol jet printing (AJP)—an additive manufacturing (AM) process—are to: (1) realize in situ online monitoring of print quality in terms of line/electronic trace morphology; and (2) explain the causal aerodynamic interactions that govern line morphology based on a two-dimensional computational fluid dynamics (2D-CFD) model. To realize these objectives, an Optomec AJ-300 aerosol jet printer was instrumented with a charge coupled device (CCD) camera mounted coaxial to the nozzle (perpendicular to the platen). Experiments were conducted by varying two process parameters, namely, sheath gas flow rate (ShGFR) and carrier gas flow rate (CGFR). The morphology of the deposited lines was captured from the online CCD images. Subsequently, using a novel digital image processing method proposed in this study, six line morphology attributes were quantified. The quantified line morphology attributes are: (1) line width, (2) line density, (3) line edge quality/smoothness, (4) overspray (OS), (5) line discontinuity, and (6) internal connectivity. The experimentally observed line morphology trends as a function of ShGFR and CGFR were verified with computational fluid dynamics (CFD) simulations. The image-based line morphology quantifiers proposed in this work can be used for online detection of incipient process drifts, while the CFD model is valuable to ascertain the appropriate corrective action to bring the process back in control in case of a drift.

The Effect of Weld Gas Flow Rate on Al-Li Weldability

1993 ◽  
Vol 115 (3) ◽  
pp. 263-267
Author(s):  
L. F. Martinez ◽  
J. C. McClure ◽  
A. C. Nunes
Keyword(s):  
Flow Rate ◽  
Arc Welding ◽  
Gas Flow ◽  
Plasma Arc Welding ◽  
Plasma Arc ◽  
Gas Flow Rate ◽  
Welding Arc ◽  
Variable Polarity ◽  
Variable Polarity Plasma Arc

Adequate shield and plasma gas flow rate during plasma arc welding are crucial factors in achieving high quality welds. Too low a shield gas flow rate lets atmosphere enter into the arc and too high a rate wastes weld gas and may cause turbulence and entrain atmosphere. Sufficient plasma gas flow is required for keyhole welding and, as shown in this paper, can reduce hydrogen contamination in the weld. In-situ optical spectroscopy used to detect oxygen and hydrogen in the welding arc during variable polarity plasma arc (VPPA) welding of aluminum 2090 revealed that there is an easily detected critical shield gas flow rate needed to exclude atmosphere and that this critical rate can be used to automatically control gas flow rates during welding.

Process parameters investigation of a laser-generated single clad for minimum size using design of experiments

2013 ◽  
Vol 19 (6) ◽  
pp. 452-462 ◽  
Author(s):  
Mehmet Ermurat ◽  
Mehmet Ali Arslan ◽  
Fehmi Erzincanli ◽  
Ibrahim Uzman
Keyword(s):  
Design Of Experiments ◽  
Process Parameters ◽  
Flow Rate ◽  
Gas Flow ◽  
Optimum Parameter ◽  
Travel Speed ◽  
Standoff Distance ◽  
Gas Flow Rate ◽  
Focal Distance ◽  
Content Type

Purpose – This paper aims to investigate the effect of four important process parameters (i.e. laser focal distance, travel speed, feeding gas flow rate and standoff distance) on the size of single clad geometry created by coaxial nozzle-based powder deposition by high power laser. Design/methodology/approach – Design of experiments (DOE) and statistical analysis methods were both used to find optimum parameter combinations to get minimum sized clad, i.e. clad width and clad height. Factorial experiment arrays were used to design parameter combinations for creating experimental runs. Taguchi optimization methodology was used to find out optimum parameter levels to get minimum sized clad geometry. Response surface method was used to investigate the nonlinearity among parameters and variance analysis was used to assess the effectiveness level of each problem parameters. Findings – The overall results show that wisely selected four problem parameters have the most prominent effects on the final clad geometry. Generally, minimum clad size was achieved at higher levels of gas flow rate, travel speed and standoff distance and at minimum spot size level of the laser focal distance. Originality/value – This study presents considerable contributions in assessing the importance level of problems parameters on the optimum single clad geometry created laser-assisted direct metal part fabrication method. This procedure is somewhat complicated in understanding the effects of the selected problem parameters on the outcome. Therefore, DOE methodologies are utilized so that this operation can be better modeled/understood and automated for real life applications. The study also gives future direction for research based on the presented results.

Uniform Ultra-Thin Oxides Grown by Rapid Thermal Oxidation of Silicon in N2O Ambient

1997 ◽  
Vol 470 ◽  
Author(s):  
G. C. Xing ◽  
D. Lopes ◽  
G. E. Miner
Keyword(s):  
Thermal Oxidation ◽  
Process Parameters ◽  
Flow Rate ◽  
Atmospheric Pressure ◽  
Gas Flow ◽  
Rotation Speed ◽  
Oxide Thickness ◽  
Gas Flow Rate ◽  
Rapid Thermal Oxidation ◽  
Nitrogen Concentrations

ABSTRACTIn this paper, we report the study of rapid thermal oxidation of silicon in N2O ambient using the Applied Materials RTP Centura rapid thermal processor, and N2O oxide thickness and compositional uniformities with respect to gas flow rate and wafer rotation speed as well as other process parameters. It was found that N2O oxide uniformity is strongly dependent on gas flow rate and wafer rotation speed in addition to process pressure. With optimized setting of the process parameters, excellent oxidation uniformities (one sigma < 1%) were obtained at atmospheric pressure N2O ambient. Nitrogen concentrations of such uniform oxides grown at 1050°C atmospheric pressure N2O oxidation processes were 1.7% for a 40Å oxide and 2.5% for a 60Å oxide, respectively, as characterized by SIMS analysis.

Desulfurization of Hot Metal Through In Situ Generation of Magnesium in 30-kg Molten Iron Bath-Influence of Inert Gas Flow Rate

2013 ◽  
Vol 85 (5) ◽  
pp. 927-934 ◽  
Author(s):  
Anil Kumar ◽  
Zachariah Elanjickal Chacko ◽  
Madurai Malathi ◽  
Kesri Mino Godiwalla ◽  
Satish Kumar Ajmani ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Molten Iron ◽  
Inert Gas ◽  
Gas Flow Rate ◽  
Hot Metal ◽  
In Situ Generation ◽  
Iron Bath

Metal Inert Gas (MIG) Welding Process Optimization for Joining Aluminum 5754 Sheet Material Using OTC/Daihen Equipment

Manufacturing ◽  
2003 ◽  
Author(s):  
R. Koganti ◽  
C. Karas ◽  
A. Joaquin ◽  
D. Henderson ◽  
M. Zaluzec ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Process Parameters ◽  
Flow Rate ◽  
Gas Flow ◽  
Power Input ◽  
Interaction Effects ◽  
Inert Gas ◽  
Weld Penetration ◽  
Mig Welding ◽  
Gas Flow Rate

The development of lightweight vehicles, in particular aluminum intensive vehicles, require significant manufacturing process development for joining and assembling aluminum structures. Currently, 5xxx and 6xxx aluminum alloys are being used in various structural applications in a number of lightweight vehicles worldwide. Various joining methods, such as MIG, Laser and adhesive bonding have been investigated as technology enables for high volume joining of 5xxx, and 6xxx series alloys. In this study, metal inert gas (MIG) welding is used to join 5754 non-heat-treatable alloy sheet products. The objective of this study is to develop optimum weld process parameters for non-heat-treatable 5754 aluminum alloys. The MIG welding equipment used in this study is an OTC/Daihen CPD-350 welding systems and DR-4000 pulse power supply. The factors selected to understand the influence of weld process parameters on the mechanical properties and metallurgy (weld penetration) include power input (torch speed, voltage, current, wire feed), pulse frequency, and gas flow rate. Test coupons used in this study were based on a single lap configuration. A full factorial design of experiment (DOE) was conducted to understand the main and interaction effects on joint failure and weld penetration. The joint strengths and weld penetrations are measured for various operating ranges of weld factors. Post weld analysis indicates, power input and gas flow rate are the two signficant factors (statistically) based on lap shear load to failure and weld penentration data. There were no 2-way or 3-way interaction effects observed in ths weld study. Based on the joint strength and weld penetration, optimum weld process factors were determined.

Optimization of Process Parameters in Laser Welding of Hastelloy C-276 Using Artificial Neural Network and Genetic Algorithm

2020 ◽  
pp. 2050042
Author(s):  
K. R. SAMPREET ◽  
VASAREDDY MAHIDHAR ◽  
R. KARTHIC NARAYANAN ◽  
T. DEEPAN BHARATHI KANNAN
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Artificial Neural Network ◽  
Laser Welding ◽  
Process Parameters ◽  
Flow Rate ◽  
Gas Flow ◽  
Back Propagation ◽  
Gas Flow Rate ◽  
Bead Width

In this paper, an effort is made to determine the optimized parameters in laser welding of Hastelloy C-276 using Artificial Neural Network (ANN) and Genetic Algorithm (GA). CO2 Laser welding was performed on a sheet of thickness 1.6[Formula: see text]mm based on Taguchi L27 orthogonal array. Laser power, welding speed and shielding gas flow rate were chosen as input parameters and Bead width, depth of Penetration and Microhardness were measured for assessing the weld quality. ANN was applied for modeling the welding process parameters i.e. heat input, welding speed and gas flow rate. Various learning algorithms such as Batch Back Propagation (BBP), Incremental Back Propagation (IBP), Quick Propagation (QP) and Levenberg–Marquardt (LM) were comprehensively tested for estimating the output parameters and a comparison was also made among them, with respect to prediction accuracy. BBP method was found to be the best learning algorithm. Experimental validation test was performed based on the ANN and GA predicted optimized responses and this welding input parameters provided satisfactory weld metal characteristics in terms of penetration depth, bead width and microhardness.

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