scholarly journals Modelling the Heating Process in Simultaneous Laser Transmission Welding of Semicrystalline Polymers

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Christian Hopmann ◽  
Suveni Kreimeier
Keyword(s):  
Welding Process ◽  
Intensity Profile ◽  
Measuring System ◽  
Heating Process ◽  
Laser Transmission Welding ◽  
Measurement Systems ◽  
Component Design ◽  
High Concordance ◽  
Joining Process

Laser transmission welding is an established joining process for thermoplastics. A close-to-reality simulation of the heating process would improve the understanding of the process, facilitate and shorten the process installation, and provide a significant contribution to the computer aided component design. For these reasons a thermal simulation model for simultaneous welding was developed which supports determining the size of the heat affected zone (HAZ). The determination of the intensity profile of the laser beam after the penetration of the laser transparent semicrystalline thermoplastic is decisive for the simulation. For the determination of the intensity profile two measurement systems are presented and compared. The calculated size of the HAZ shows a high concordance to the dimensions of the HAZ found using light microscopy. However, the calculated temperatures exceed the indicated decomposition temperatures of the particular thermoplastics. For the recording of the real temperatures during the welding process a measuring system is presented and discussed.

Automation of selected brazes' dynamic properties in high-temperatures' measurement process

2013 ◽  
Vol 18 (2-3) ◽  
pp. 33-41
Author(s):  
Dominik Sankowski ◽  
Marcin Bakala ◽  
Rafał Wojciechowski
Keyword(s):  
Surface Tension ◽  
High Temperatures ◽  
Dynamic Properties ◽  
Automatic Measurement ◽  
Measurement Methodology ◽  
Joining Process ◽  
Wetting Force ◽  
Research Grant

Abstract The good quality of several manufactured components frequently depends on solidliquid interactions existing during processing. Nowadays, the research in material engineering focuses also on modern, automatic measurement methods of joining process properties, i.a. wetting force and surface tension, which allows for quantitative determination of above mentioned parameters. In the paper, the brazes’ dynamic properties in high-temperatures’ measurement methodology and the stand for automatic determination of braze’s properties, constructed and implmented within the research grant nr KBN N N519 441 839 - An integrated platform for automatic measurement of wettability and surface tension of solders at high temperatures, are widely described

Metodología para el desarrollo de trayectorias en la aplicación por el proceso de soldadura GMAW en un robot industrial

2019 ◽  
pp. 1-4
Author(s):  
Josué Rafael Sánchez-Lerma ◽  
Luis Armando Torres-Rico ◽  
Héctor Huerta-Gámez ◽  
Ismael Ruiz-López
Keyword(s):  
Mechanical Properties ◽  
Automotive Industry ◽  
Industrial Robot ◽  
Welding Process ◽  
High Strength ◽  
Test Material ◽  
Advantages And Disadvantages ◽  
Application Characteristics ◽  
Joining Process ◽  
Gmaw Welding

This paper proposes the development of the methodology to be carried out for the metal joining process through the GMAW welding process in the Fanuc LR Mate 200iD industrial robot. The parameters or properties were considered for the application to be as efficient as possible, such parameters as speed of application, characteristics of the filler material, gas to be used as welding protection. The GMAW welding process can be applied semiautomatically using a hand gun, in which the electrode is fed by a coil, or an automatic form that includes automated equipment or robots. The advantages and disadvantages of the GMAW welding process applied in a manual and automated way were commented. The mechanical properties of the materials to which said welding can be applied were investigated; The materials with which this type of welding can be worked are the high strength materials, which are used in the automotive industry, for the forming of sheet metal. To know the properties of the material, destructive tests were carried out on the test material to be used, as well as the mechanical properties of the welding.

scholarly journals A design concept of active cooling for tailored forming workpieces during induction heating

2021 ◽  
Vol 15 (2) ◽  
pp. 177-186
Author(s):  
Caner-Veli Ince ◽  
Anna Chugreeva ◽  
Christoph Böhm ◽  
Fadi Aldakheel ◽  
Johanna Uhe ◽  
...  
Keyword(s):  
Dissimilar Materials ◽  
Heating Process ◽  
Algorithmic Approach ◽  
Cooling Strategy ◽  
Heating And Cooling ◽  
Temperature Constraint ◽  
Inhomogeneous Temperature ◽  
Specific Temperature ◽  
Tailored Forming

AbstractThe demand for lightweight construction is constantly increasing. One approach to meet this challenge is the development of hybrid components made of dissimilar materials. The use of the hybrid construction method for bulk components has a high potential for weight reduction and increased functionality. However, forming workpieces consisting of dissimilar materials requires specific temperature profiles for achieving sufficient formability. This paper deals with the development of a specific heating and cooling strategy to generate an inhomogeneous temperature distribution in hybrid workpieces. Firstly, the heating process boundaries with regard to temperature parameters required for a successful forming are experimentally defined. Secondly, a design based on the obtained cooling strategy is developed. Next a modelling embedded within an electro-thermal framework provides the basis for a numerical determination of admissible cooling rates to fulfil the temperature constraint. Here, the authors illustrate an algorithmic approach for the optimisation of cooling parameters towards an effective minimum, required for applicable forming processes of tailored forming.

scholarly journals Raman Sensor for the Determination of Gas Solubility

Physchem ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 176-188
Author(s):  
Gregor Lipinski ◽  
Markus Richter
Keyword(s):  
Carbon Dioxide ◽  
Gas Separation ◽  
Accurate Determination ◽  
Measurement Techniques ◽  
Screening Tools ◽  
Measuring System ◽  
Separation Processes ◽  
Use Of Resources ◽  
Gas Solubilities

Efficient and environmentally responsible use of resources requires the development and optimization of gas separation processes. A promising approach is the use of liquids that are designed for specific tasks, e.g., the capture of carbon dioxide or other greenhouse gases. This requires an accurate determination of gas solubilities for a broad range of temperatures and pressures. However, state of the art measurement techniques are often very time consuming or exhibit other pitfalls that prevent their use as efficient screening tools. Here, we show that the application of Raman spectroscopy through a compact measuring system can simplify data acquisition for the determination of gas solubilities in liquids. To demonstrate that this approach is expedient, we determined gas solubilities of carbon dioxide in water for three isotherms T = (288.15, 293.15, 298.15) K over a pressure range from p = (0.5–5) MPa and in three imidazolium-based ionic liquids for one isotherm T = 298.15 K at pressures from p = (0.1–5) MPa. When compared to data in the literature, all results are within the reported uncertainties of the measurement techniques involved. The developed analysis method eliminates the need for a lengthy volume or mass calibration of the sample prior to the measurements and, therefore, allows for fast screening of samples, which can help to advance gas separation processes in scientific and industrial applications.

scholarly journals Friction Stir Welding of Aerospace Alloys

2019 ◽  
Vol 48 (1) ◽  
pp. 37-46
Author(s):  
Akshansh Mishra ◽  
Devarrishi Dixit
Keyword(s):  
Friction Stir Welding ◽  
Welding Process ◽  
Space Vehicles ◽  
Friction Stir ◽  
Aerospace Applications ◽  
Aerospace Alloys ◽  
Fuel Tanks ◽  
Higher Temperature ◽  
Solid State Joining ◽  
Joining Process

Friction Stir Welding (FSW) is a solid state joining process which possesses a great potential to revolutionise the aerospace industries. Distinctive materials are selected as aerospace alloys to withstand higher temperature and loads. Sometimes these alloys are difficult to join by a conventional welding process but they are easily welded by FSW process. The FSW process in aerospace applications can be used for: aviation for fuel tanks, repair of faulty welds, cryogenic fuel tanks for space vehicles. Eclipse Aviation, for example, has reported dramatic production cost reductions with FSW when compared to other joining technologies. This paper will discuss about the mechanical and microstructure properties of various aerospace alloys which are joined by FSW process.

Public Accountability or Fiscal Control? Benchmarks of Performance in Australian Schooling

1996 ◽  
Vol 40 (1) ◽  
pp. 104-123 ◽  
Author(s):  
Louise Watson
Keyword(s):  
Performance Indicators ◽  
Service Provision ◽  
School Effectiveness ◽  
Measuring System ◽  
Government Schools ◽  
Public Resources ◽  
Government Education ◽  
Efficiency And Effectiveness ◽  
Performance Benchmarks

The Industry Commission review of service provision in school education aims to define performance benchmarks for Australia's eight government education systems, by providing comparative measures of efficiency in education provision. Such benchmarks are likely to lead to a reduction in the level of public resources for government schools unless it is possible to demonstrate the link between expenditure on schooling and school effectiveness. If efficiency audits like the Industry Commission review are to deal with issues of school effectiveness adequately, they should avoid the tendency of previous public sector audits to focus on financial data on schools expenditure to the exclusion of data on student achievement. This paper suggests an approach to measuring system performance which would establish benchmarks that reflected both the efficiency and effectiveness of Australian school systems, and warns against the misuse of performance indicators as an instrument in the determination of funding levels for schools.

Microstructure Development in Copper Welded by the FSW-Process

2003 ◽  
Vol 807 ◽  
Author(s):  
Therese Källgren ◽  
Rolf Sandström
Keyword(s):  
Welding Process ◽  
Mechanical Deformation ◽  
Microstructure Development ◽  
Friction Stir ◽  
Friction Heat ◽  
The Third ◽  
Lower Temperature ◽  
Weld Root ◽  
Nuclear Fuel Waste ◽  
Joining Process

ABSTRACTTo ensure safe storage of nuclear fuel waste, copper canisters are proposed as corrosion barrier. One alternative for sealing the copper canisters is Friction Stir Welding (FSW). During the joining process friction heat and mechanical deformation appear between the rotating tool and the material being welded. Liquid metal will not form, since this is a solid state welding process. Three distinct microstructural zones are developed namely the nugget, the thermo-mechanically affected zone (TMAZ) and heat-affected zone (HAZ). The nugget is in the centre of the weld, where the pin is located and where severe plastic deformation occurs that leads to recrystallisation. Surrounding the nugget, the TMAZ is only partially recrystallised, due to lower temperature increase and deformation compared to the nugget. The third zone, HAZ, surrounds the TMAZ. The initial nugget can have a classic round aluminium nugget image, when the welding conditions are cold, but the steady state nugget, is wider near the shoulder and shorter in the weld root.

Real-time performance of filtering facepiece respirators at the workplace/Echtzeit-Performance partikelfiltrierender Halbmasken am Arbeitsplatz

Gefahrstoffe ◽  
2019 ◽  
Vol 79 (10) ◽  
pp. 378-384
Author(s):  
C. Sun ◽  
C. Thelen ◽  
I. Sancho Sanz ◽  
A. Wittmann
Keyword(s):  
Field Measurements ◽  
Paper Mill ◽  
Measuring System ◽  
Pilot Test ◽  
Protection Factor ◽  
Workplace Performance ◽  
Geometric Means ◽  
Training Facility ◽  
Workplace Conditions

The efficacy of a respirator under real workplace conditions is presented by its workplace protection factor (WPF). The aim of this study was to assess a portable measuring system for the determination of WPF for particulate filtering facepiece respirators. WPFs of CE-marked FFP2 and FFP3 filtering facepiece respirators were measured as a pilot test conducted at two workplaces: an inter-company training facility and a paper mill, with a total of seven test subjects. Each subject was quantitatively fit tested prior to the field measurements. Two TSI PortaCount instruments measured the particle concentrations simultaneously and continuously inside and outside the respirator for 15 min, with three repetitions. The results of the fit test (overall fit factor) ranged from 22 to 199. Individual WPF results ranged from 16 to 568 for FFP2 respirators, and from 13 to 232 for FFP3 respirators. The geometric means (GM) of the WPF were 135 with a 5th percentile value of 37 (FFP2), and 47 with a 5th percentile value of 12 (FFP3). This pilot test provides a new method of evaluating the workplace performance of filtering facepiece respirators.

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