Large-Diameter Line Pipe Expanding Process

2012 ◽  
Vol 192 ◽  
pp. 180-184 ◽  
Author(s):  
Ai Xia He ◽  
Rong Chang Li

Mechanical expanding process for large diameter line pipe, a detailed analysis of factors affecting the quality of the final products of the mechanical expansion and proposed optimization using orthogonal array optimization method, as an indicator of dimensional accuracy and shape accuracy of the products, combination of a variety of specifications of mechanical expanding products, the main process parameters to be optimized. Analysis and discussion of results, revealing the degree of influence of various factors on the quality of the final product, and gives the optimum combination of the results. Experiments show that the combination of optimized process parameters, and more help to improve the accuracy of the size and shape of products.

Author(s):  
Lara Rebaioli ◽  
Irene Fassi

Abstract Lab on Chips (LOCs) are devices, mostly based on microfluidics, that allow to perform one or several chemical, biochemical or biological analysis in a miniaturized format on a single chip. The Additive Manufacturing processes, and in particular the Digital Light Processing stereolithography (DLP-SLA), could quickly produce a complete LOC with high resolution 3D features in a single step, i.e. without the need for assembly processes, and using low cost and user-friendly desktop machines. However, the potential of DLP-SLA to produce non-planar channels or channels with complex sections has not been fully investigated yet. This study proposes a benchmark artifact (including also some channels with their axis lying in a plane parallel to the machine building platform) aiming at assessing the capability and performance of DLP-SLA for manufacturing microfeatures for microfluidic devices. A proper experimental campaign was performed to evaluate the effect of the main process parameters (namely, layer thickness and exposure time) on the process performance. The results pointed out that both the process parameters influence the quality and dimensional accuracy of the analyzed features.


2014 ◽  
Vol 884-885 ◽  
pp. 345-348 ◽  
Author(s):  
Lei Shang ◽  
Hai Li Yang ◽  
Hong Xu ◽  
Yun Gang Li

Magnetic properties of silicon steel mainly depend on the internal organizational structure and chemical composition. The main factors affecting magnetic properties of silicon steel are analyzed and summarized, including grain size, inclusions (size, type, quantity, and morphology), crystal texture, internal stress, dimensional accuracy, the surface quality of steels, and chemical composition. The impact mechanism of the factors influencing silicon steel magnetic property is explained and these influence factors are interrelated.


Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3667
Author(s):  
Jindian Zhang ◽  
Zongbao Shen ◽  
Youyu Lin ◽  
Kai Liu ◽  
Guoyang Zhou ◽  
...  

Laser pre-shocking (LPS) was introduced into the laser dynamic flexible micropunching process to refine the grain size of a workpiece to improve the forming quality of punched parts. T2 copper foils with five different grain sizes and seven different laser power densities with and without LPS were used for the experiment. The results showed that the grains are refined and the average surface roughness Ra decreases after LPS. For copper foils annealed at 650 °C, the value of Ra decreases from 0.430 to 0.363 µm. The increase in laser energy density and grain size leads to the deterioration of the fracture surface. LPS can improve the quality of the fracture surface. Compared with punched holes without LPS, the dimensional accuracy and shape accuracy of punched holes can be improved by LPS. When grain size is close to the thickness of the copper foil, the forming quality of the punched parts becomes uncertain, owing to the difference in the orientation of the initial grains. The instability of laser dynamic flexible micropunching can be reduced by LPS. Especially, the improvement of forming quality of the punched part brought by LPS is significant for the copper foils with coarse grains.


2018 ◽  
Vol 190 ◽  
pp. 15010 ◽  
Author(s):  
Hamza Messaoudi ◽  
Florian Böhmermann ◽  
Merlin Mikulewitsch ◽  
Axel von Freyberg ◽  
Andreas Fischer ◽  
...  

Laser chemical machining, a non-conventional processing method based on thermally activated electrochemical material dissolution, represents a promising technology for manufacturing metallic dies for micro forming applications. Prior to widespread industrial acceptance the machining quality of laser chemical machining should be characterized. For this purpose, laser chemical machining is compared with micro milling regarding both the dimensional accuracy and the surface quality. Therefore, square micro cavities exhibiting side walls between 100 μm and 400 μm in length and 60 μm in depth are machined with both manufacturing processes into the cobalt-chrome alloy Stellite 21. The geometrical features are investigated using laser-scanning confocal microscopy and scanning electron microscopy. On the one hand, laser chemical machining is more suitable for manufacturing cavities with dimensions < 200 μm due to higher shape accuracy with stable mean edge radii of (11.2 ± 1.3) μm as a result of roughing and finishing steps. On the other hand, the finish quality of micro milling with mean surface roughness Sa of 0.2 μm could not be achieved with laser chemical machining due to in-process induced waviness. Finally, the metallographic analysis of the surface-near layers reveals that both manufacturing processes ensure gentle machining without any noticeable micro structural impact.


2014 ◽  
Vol 852 ◽  
pp. 523-528
Author(s):  
Qin Xiang Xia ◽  
Liang Bo Ji ◽  
Bao Hua Cao ◽  
You Xiang Li

Blanking finite element analysis model of non-metallic material PET insulation spacer was established, and the influence of process parameters on blanking quality of insulation spacer was analyzed. The results show that the qualified cross-section quality, the high dimensional accuracy and the little bending distortion of blanking workpiece can be obtained by the reasonable blanking clearance and the higher blanking speed. The corresponding experiment was carried out, the results show that the process parameters of insulation spacer blanking obtained by numerical simulation are feasible, and the qualified insulation spacer was produced by the simulation results.


Author(s):  
Jagadish ◽  
Sumit Bhowmik

Fused deposition modeling (FDM) is one of the emerging rapid prototyping (RP) processes in additive manufacturing. FDM fabricates the quality prototype directly from the CAD data and is dependent on the various process parameters, hence optimization is essential. In the present chapter, process parameters of FDM process are analyzed using an integrated MCDM approach. The integrated MCDM approach consists of modified fuzzy with ANP methods. Experimentation is performed considering three process parameters, namely layer height, shell thickness, and fill density, and corresponding response parameters, namely ultimate tensile strength, dimensional accuracy, and manufacturing time are determined. Thereafter, optimization of FDM process parameters is done using proposed method. The result shows that exp.no-4 yields the optimal process parameters for FDM and provides optimal parameters as layer height of 0.08 mm, shell thickness of 2.0 mm and fill density of 100%. Also, optimal setting provides higher ultimate TS, good DA, and lesser MT as well as improving the performance and efficiency of FDM.


2012 ◽  
Vol 522 ◽  
pp. 41-46
Author(s):  
Adayi Xieeryazidan ◽  
Muhetar Wumerhali ◽  
Gui Bing Pang

Electrochemical finishing with pulsed current (ECFP) is introduced in this paper. The main process parameters, such as electric parameter and inter-electrode gap, etc., were investigated. The results show that the ECFP is an effective finishing method for improving the machining quality as the result of the machining mechanism. The related experimental results show that the obtained surface quality and dimensional accuracy are improved significantly as the result of the application of the pulsed current. Moreover, machining quality is increased with shorter pulses.


2016 ◽  
Vol 22 (6) ◽  
pp. 864-870 ◽  
Author(s):  
Athanasios Goulas ◽  
Ross J. Friel

Purpose The purpose of this paper is to investigate the effect of the main process parameters of laser melting (LM) type additive manufacturing (AM) on multi-layered structures manufactured from JSC-1A Lunar regolith (Moondust) simulant powder. Design/methodology/approach Laser diffraction technology was used to analyse and confirm the simulant powder material particle sizes and distribution. Geometrical shapes were then manufactured on a Realizer SLM™ 100 using the simulant powder. The laser-processed samples were analysed via scanning electron microscopy to evaluate surface and internal morphologies, X-ray fluorescence spectroscopy to analyse the chemical composition after processing, and the samples were mechanically investigated via Vickers micro-hardness testing. Findings A combination of process parameters resulting in an energy density value of 1.011 J/mm2 allowed the successful production of components directly from Lunar regolith simulant. An internal relative porosity of 40.8 per cent, material hardness of 670 ± 11 HV and a dimensional accuracy of 99.8 per cent were observed in the fabricated samples. Originality/value This research paper is investigating the novel application of a powder bed fusion AM process category as a potential on-site manufacturing approach for manufacturing structures/components out of Lunar regolith (Moondust). It was shown that this AM process category has the capability to directly manufacture multi-layered parts out of Lunar regolith, which has potential applicability to future moon colonization.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Lara Rebaioli ◽  
Irene Fassi

Abstract Suitable benchmark artifacts are needed for assessing the technological capabilities and limitations of a specific process or for comparing the performances of different processes. Only a few benchmark artifacts have been specifically designed for features with microscale dimensions, even if their manufacturing is becoming very common due to the increasing demand for miniaturized parts or objects with microscale features. In this study, a suitable benchmark part is designed to evaluate the geometrical performance of a digital light processing (DLP) stereolithography (SLA) system for manufacturing microfeatures. The effect of the main process parameters (i.e., layer thickness and exposure time) and the feature position within the building platform on the process performance was assessed by a specifically studied experimental campaign. The results show that both the analyzed process parameters influence the minimum feasible size of protruding features and that the feature position influences the dimensional accuracy.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2343 ◽  
Author(s):  
Ahmed Maamoun ◽  
Yi Xue ◽  
Mohamed Elbestawi ◽  
Stephen Veldhuis

Additive manufacturing (AM) of high-strength Al alloys promises to enhance the performance of critical components related to various aerospace and automotive applications. The key advantage of AM is its ability to generate lightweight, robust, and complex shapes. However, the characteristics of the as-built parts may represent an obstacle to the satisfaction of the parts’ quality requirements. The current study investigates the influence of selective laser melting (SLM) process parameters on the quality of parts fabricated from different Al alloys. A design of experiment (DOE) was used to analyze relative density, porosity, surface roughness, and dimensional accuracy according to the interaction effect between the SLM process parameters. The results show a range of energy densities and SLM process parameters for AlSi10Mg and Al6061 alloys needed to achieve “optimum” values for each performance characteristic. A process map was developed for each material by combining the optimized range of SLM process parameters for each characteristic to ensure good quality of the as-built parts. This study is also aimed at reducing the amount of post-processing needed according to the optimal processing window detected.


Sign in / Sign up

Export Citation Format

Share Document