Experimental Research of Process Parameters in Metal Droplet Deposition Manufacturing

2010 ◽  
Vol 97-101 ◽  
pp. 4028-4031 ◽  
Author(s):  
Yan Pu Chao ◽  
Le Hua Qi ◽  
Xiang Hui Zeng ◽  
Jun Luo ◽  
Hua Huang
Keyword(s):  
Layer Thickness ◽  
Experimental Research ◽  
Process Parameters ◽  
Manufacturing Process ◽  
Droplet Diameter ◽  
Metal Droplet ◽  
Experimental System ◽  
Droplet Deposition ◽  
High Quality ◽  
Experimental Parameters

In the droplet-based manufacturing process, the accuracy and density of forming parts are determined by experimental parameters such as the velocity and temperature of substrate, droplets spraying frequency, line deposition space and layer thickness etc. Using Sn60-Pb40, the droplets deposition experiment was conducted to investigate the effect of the parameters on the accuracy and density of formed lines, layers and solids on the experimental system. The experiment results showed that the high quality lines were obtained when the overlapping ratio of the adjacent droplets was controlled around 30% by the substrate velocity and droplet spraying frequency, meanwhile，the temperatures of the substrate and droplet were maintained at 270°C and 140°C, respectively. When the lines deposited space was about 90% of droplet diameter and the layer thickness was about 80% of droplet diameter, good deposition results of layers and solids can be obtained. This work has offered experimental guide for metal droplet deposition manufacturing.

Experimental research on the deep-hole boring of pure niobium tube

2020 ◽  
Vol 234 (8) ◽  
pp. 1124-1132
Author(s):  
Xiaolan Han ◽  
Zhanfeng Liu ◽  
Yazhou Feng
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Experimental Research ◽  
Process Parameters ◽  
Cutting Tool ◽  
Geometric Parameters ◽  
Deep Hole ◽  
High Quality ◽  
Pure Niobium ◽  
Hole Axis

In the deep-hole boring process on pure niobium tube, there exist some problems including serious tool wear, tough chips, and poor surface quality. In order to bore high-quality deep holes on rolled niobium tube, the cutting tool structure and boring process parameters suitable for machining rolled niobium tube were designed and two experimental schemes were proposed. The results showed that the geometric parameters of the cutting tool and process parameters have important influences on the tool wear, chip morphologies, hole-axis deflection, and hole surface roughness. By adjusting the geometric parameters of the cutting tool and boring process parameters, reasonable geometric parameters of the cutting tool and boring process parameters were obtained.

Experimental Research on Laser Transmission Micro-Joining Based on the Mask

2014 ◽  
Vol 620 ◽  
pp. 17-22
Author(s):  
Cai Lian Fan ◽  
Hui Xia Liu ◽  
Zhen Guan Zhao ◽  
Yan Wei Wu ◽  
Xiao Wang
Keyword(s):  
Experimental Research ◽  
Process Parameters ◽  
Weld Joint ◽  
Joint Strength ◽  
High Quality ◽  
Weld Geometry ◽  
Medical Microbiology ◽  
Joint Width ◽  
Materials Used ◽  
Gap Width

With the demand of high-quality and aesthetical products in the domain of medical microbiology, it’s more and more important to join micro weld. Due to traditional joining methods’ difficulty in meeting the demands, laser transmission micro-joining is of great significance. The materials used to laser transmission micro-joining based on the mask are PET, and the experiments are conducted on diode laser. The weld geometry with different gap widths on the mask is demonstrated at the same process parameters. In addition, the causes of forming different morphologies are analyzed. The formation mechanism of weld is analyzed as well. Moreover, process parameters’ effects on joint strength and joint width are deeply explored when gap width on the mask is 0.3mm. The results show that100 um micro weld joint is realized. At the same time, the range of process parameters is determined.

Effect of Process Parameters on Splat Formation during Impingement of Liquid Metal Droplets over a Cold Substrate

2012 ◽  
Vol 710 ◽  
pp. 186-191
Author(s):  
Amitesh Kumar ◽  
Seshadev Sahoo ◽  
Sudipto Ghosh ◽  
Brij Kumar Dhindaw
Keyword(s):  
Heat Transfer ◽  
Liquid Metal ◽  
Process Parameters ◽  
Liquid Droplet ◽  
Solidification Rate ◽  
Experimental Studies ◽  
Metal Droplet ◽  
Droplet Deposition ◽  
Splat Formation ◽  
Spray Casting

Molten metal droplet impingement is an integral part of droplet based manufacturing processes like spray casting and sprays coating. In these processes, in a single operation, a liquid metal stream is atomized into fine droplets, which impact on a substrate to form a bulk deposit. The properties of casting or coating strongly depend on the shape of splats formed by individual droplets after impingement and solidification. Therefore, considerable research studies have been carried out to characterize individual droplet impact, usually driven by an interest in a particular process. These studies include extensive modeling of droplet deposition, some of which are supported by experimental studies. Most of these modeling activities have focused on the impingement of a droplet on to a surface to predict quantities such as the extent of maximum spread and the final equilibrium diameter, the rate of heat transfer to the substrate, and the solidification rate. Due to interaction of several complex phenomena, comprehensive modeling of the droplet deposition is a challenging task. The flow of liquid droplet upon impingement is itself a complex phenomenon. Heat transfer and solidification occurring concurrently with the flow adds further to the complexity. Thus the present study aims at the development of a comprehensive mathematical model of impingement of liquid metal droplet upon a substrate to understand the effect of process parameters such as initial temperature of droplet, size of droplet and velocity of droplet.

Optimization of build orientation in FFF using response surface methodology and posterior-based method

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammad Javad Hooshmand ◽  
Saeed Mansour ◽  
Amin Dehghanian
Keyword(s):  
Layer Thickness ◽  
Process Parameters ◽  
Empirical Models ◽  
High Quality ◽  
Content Type ◽  
Build Orientation ◽  
Build Time ◽  
Raster Angle ◽  
Quality Surface ◽  
Response Variables

Purpose The advancement of additive manufacturing technologies has resulted in producing parts of high quality and reduced manufacturing time. This paper aims to achieve a simultaneous optimal solution for build time and surface roughness as the output data and also to find the best values for the input data consisting of build orientation, extrusion width, layer thickness, infill percentage and raster angle. Design/methodology/approach For this purpose, the effects of process parameters on the response variables were investigated by the design of experiments approach to develop empirical models using response surface methodology. The experimental parts of this research were conducted using an inexpensive and locally assembled fused filament fabrication (FFF) machine. A total of 50 runs for 4 different geometries, namely, cylinder, prism, 3DBenchy and twist gear vase, were performed using the rotatable central composite design, and each process parameters were investigated in two levels to develop empirical models. Also, a novel optimization method, namely, the posterior-based method, was accomplished to find the best values for the response variables. Findings The results demonstrated that not only the build orientation and layer thickness have notable effects on both response variables but also build time is dependent on extrusion width and infill percentage. Low infill percentage and high extrusion width resulted in increasing build time. By reducing layer thickness and infill percentage while increasing extrusion width, parts of high-quality surface finish and reduced built time were produced. Optimum process parameters were found to be of build direction of 0°, extrusion width of 0.61 mm, layer thickness of 0.22 mm, infill percentage of 20% and raster angle of 0°. Originality/value Through the developed empirical models and by minimizing build orientation and layer thickness, and also considerations for process parameters, parts of high-quality surface finish and reduced built time could be produced on FFF machines. To compensate for increased build time because of reduction in layer thickness, extrusion width and infill percentage must have their maximum and minimum value, respectively.

scholarly journals The Additive Manufacturing Process of Electric Power Fittings Fabricated by Metal Droplet Deposition

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Zhengying Wei ◽  
HaiHua Wu ◽  
Guangxi Zhao
Keyword(s):  
Additive Manufacturing ◽  
Electric Power ◽  
Manufacturing Process ◽  
Metal Droplet ◽  
Dimensional Accuracy ◽  
Transportation Cost ◽  
Average Density ◽  
Raw Material ◽  
Support Material ◽  
Droplet Deposition

Metal droplet deposition is a kind of additive manufacturing (3D Printing) technique that fabricates near-net part through droplets deposition with lower cost and higher efficiency. This paper proposed a solution to problems of electric power fittings that large inventories, high procurement costs, low manufacturing efficiency and transportation cost. Using additive Manufacturing technique - metal droplet deposition, electric power fittings fabricated on power construction site. This paper describes the manufacturing process of typical thin-walled samples (the structure optimized based on additive manufacturing principle) and ball head rings of electric power fittings. Aiming at the integral AM forming for ball and ball socket electric power fitting workpiece, a novel easy removal forming support material (ceramics and gypsum mixed with UV cured resin) have been developed. Here this support material was used to fabricate nested integral workpieces. Dimensional accuracy and microstructure of the test pieces were analyzed. The error of the height and width of the forming workpiece is within 5%. No obvious overlap trace (such as overlap line and cracks) observed, and the internal microstructure is equiaxial crystal. The average density of the component is 99.51%, which measured by drainage method and 13.39% higher than the cast raw material.

Application Of Cusum Chart In Control Of Paper Quality

GIS Business ◽  
2020 ◽  
Vol 14 (6) ◽  
pp. 1062-1069
Author(s):  
S.Ramesh ◽  
B.A.Vasu
Keyword(s):  
Process Parameters ◽  
Manufacturing Process ◽  
Paper Industry ◽  
Primary Data ◽  
Cusum Chart ◽  
Paper Machine ◽  
Statistical Control ◽  
Operating Characteristics ◽  
Small Shift

This paper is an attempt to assess if the manufacturing process of paper machine is in statistical control thereby improving the quality of paper being produced in a paper industry at the time of process itself. Quality is the foremost criteria for achieving the business target. Therefore, emphasis was made on controlling the quality of paper at the time of manufacturing process itself, rather than checking the finished lots at a later time.  This control on quality will help the industry deduct the small shift in the process parameters and modify the operating characteristics at the time of production itself rather than receiving complaints from customers at a later stage.  This paper describes controlling quality at the time of manufacture itself and helps the industry to concentrate on quality at low cost. The researcher has collected primary data at a leading paper industry during October, 2019.  Though X-bar and Range charges were primarily used, CUSUM charts were used to sense the minor shifts in manufacturing process, to explore the possibility of adjusting process parameters during manufacture of paper.

scholarly journals UV Nanoimprint Lithography: Geometrical Impact on Filling Properties of Nanoscale Patterns

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 822
Author(s):  
Christine Thanner ◽  
Martin Eibelhuber
Keyword(s):  
Layer Thickness ◽  
Process Parameters ◽  
Nanoimprint Lithography ◽  
Failure Modes ◽  
Production Method ◽  
Efficient Production ◽  
Comprehensive Overview ◽  
Replication Method ◽  
Wide Range ◽  
Pattern Size

Ultraviolet (UV) Nanoimprint Lithography (NIL) is a replication method that is well known for its capability to address a wide range of pattern sizes and shapes. It has proven to be an efficient production method for patterning resist layers with features ranging from a few hundred micrometers and down to the nanometer range. Best results can be achieved if the fundamental behavior of the imprint resist and the pattern filling are considered by the equipment and process parameters. In particular, the material properties and pattern size and shape play a crucial role. For capillary force-driven filling behavior it is important to understand the influencing parameters and respective failure modes in order to optimize the processes for reliable full wafer manufacturing. In this work, the nanoimprint results obtained for different pattern geometries are compared with respect to pattern quality and residual layer thickness: The comprehensive overview of the relevant process parameters is helpful for setting up NIL processes for different nanostructures with minimum layer thickness.

scholarly journals Investigation of the Heteroepitaxial Process Optimization of Ge Layers on Si (001) by RPCVD

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 928
Author(s):  
Yong Du ◽  
Zhenzhen Kong ◽  
Muhammet Toprak ◽  
Guilei Wang ◽  
Yuanhao Miao ◽  
...  
Keyword(s):  
High Temperature ◽  
Buffer Layer ◽  
Layer Thickness ◽  
Growth Temperature ◽  
Crystalline Quality ◽  
Initial Growth ◽  
Two Dimensional ◽  
High Quality ◽  
Reduced Pressure

This work presents the growth of high-quality Ge epilayers on Si (001) substrates using a reduced pressure chemical vapor deposition (RPCVD) chamber. Based on the initial nucleation, a low temperature high temperature (LT-HT) two-step approach, we systematically investigate the nucleation time and surface topography, influence of a LT-Ge buffer layer thickness, a HT-Ge growth temperature, layer thickness, and high temperature thermal treatment on the morphological and crystalline quality of the Ge epilayers. It is also a unique study in the initial growth of Ge epitaxy; the start point of the experiments includes Stranski–Krastanov mode in which the Ge wet layer is initially formed and later the growth is developed to form nuclides. Afterwards, a two-dimensional Ge layer is formed from the coalescing of the nuclides. The evolution of the strain from the beginning stage of the growth up to the full Ge layer has been investigated. Material characterization results show that Ge epilayer with 400 nm LT-Ge buffer layer features at least the root mean square (RMS) value and it’s threading dislocation density (TDD) decreases by a factor of 2. In view of the 400 nm LT-Ge buffer layer, the 1000 nm Ge epilayer with HT-Ge growth temperature of 650 °C showed the best material quality, which is conducive to the merging of the crystals into a connected structure eventually forming a continuous and two-dimensional film. After increasing the thickness of Ge layer from 900 nm to 2000 nm, Ge surface roughness decreased first and then increased slowly (the RMS value for 1400 nm Ge layer was 0.81 nm). Finally, a high-temperature annealing process was carried out and high-quality Ge layer was obtained (TDD=2.78 × 107 cm−2). In addition, room temperature strong photoluminescence (PL) peak intensity and narrow full width at half maximum (11 meV) spectra further confirm the high crystalline quality of the Ge layer manufactured by this optimized process. This work highlights the inducing, increasing, and relaxing of the strain in the Ge buffer and the signature of the defect formation.

scholarly journals Research on Automated Defect Classification Based on Visual Sensing and Convolutional Neural Network-Support Vector Machine for GTA-Assisted Droplet Deposition Manufacturing Process

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 639
Author(s):  
Chen Ma ◽  
Haifei Dang ◽  
Jun Du ◽  
Pengfei He ◽  
Minbo Jiang ◽  
...  
Keyword(s):  
Neural Network ◽  
Support Vector Machine ◽  
Convolutional Neural Network ◽  
Manufacturing Process ◽  
Support Vector ◽  
Defect Classification ◽  
Droplet Deposition ◽  
Network Support ◽  
Visual Sensing ◽  
Low Efficiency

This paper proposes a novel metal additive manufacturing process, which is a composition of gas tungsten arc (GTA) and droplet deposition manufacturing (DDM). Due to complex physical metallurgical processes involved, such as droplet impact, spreading, surface pre-melting, etc., defects, including lack of fusion, overflow and discontinuity of deposited layers always occur. To assure the quality of GTA-assisted DDM-ed parts, online monitoring based on visual sensing has been implemented. The current study also focuses on automated defect classification to avoid low efficiency and bias of manual recognition by the way of convolutional neural network-support vector machine (CNN-SVM). The best accuracy of 98.9%, with an execution time of about 12 milliseconds to handle an image, proved our model can be enough to use in real-time feedback control of the process.

Effects of Sequential Cuts on White Layer Formation and Retained Austenite Content in Hard Turning of AISI52100 Steel

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Xiao-Ming Zhang ◽  
Xin-Da Huang ◽  
Li Chen ◽  
Jürgen Leopold ◽  
Han Ding
Keyword(s):  
Layer Thickness ◽  
Process Parameters ◽  
Retained Austenite ◽  
Hard Turning ◽  
White Layer ◽  
Layer Formation ◽  
White Layer Thickness ◽  
Austenite Content ◽  
Sequential Cuts ◽  
White Layer Formation

This technical brief is the extension of our previous work developed by Zhang et al. (2016, “Effects of Process Parameters on White Layer Formation and Morphology in Hard Turning of AISI52100 Steel,” ASME J. Manuf. Sci. Eng., 138(7), p. 074502). We investigated the effects of sequential cuts on microstructure alteration in hard turning of AISI52100 steel. Samples undergone five sequential cuts are prepared with different radial feed rates and cutting speeds. Optical microscope and X-ray diffraction (XRD) are employed to analyze the microstructures of white layer and bulk materials after sequential cutting processes. Through the studies we first find out the increasing of white layer thickness in the sequential cuts. This trend in sequential cuts does work for different process parameters, belonging to the usually used ones in hard turning of AISI52100 steel. In addition, we find that the white layer thickness increases with the increasing of cutting speed, as recorded in the literature. To reveal the mechanism of white layer formation, XRD measurements of white layers generated in the sequential cuts are made. As a result retained austenite in white layers is identified, which states that the thermally driven phase transformations dominate the white layer formation, rather than the severe plastic deformation in cuts. Furthermore, retained austenite contents in sequential cuts with different process parameters are discussed. While using a smaller radial feed rate, the greater retained austenite content found in experiments is attributed to the generated compressive surface residual stresses, which possibly restricts the martensitic transformation.

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