Increased AMS Ion Source Efficiency and Ion Currents by Modifying SNICS Cathode Material and Geometry
Publication date: 2017 Source:Physics Procedia, Volume 90 Author(s): Joshua D. Hlavenka, Henry Abrams, Mark L. Roberts, Brett E. Longworth A series of tests have been conducted at the Wood Hole Oceanographic Institution's National Ocean Sciences Accelerator Mass Spectrometry facility (NOSAMS) to investigate the effect of sample well geometry and cathode material on C− extraction efficiency and beam currents. Ion current production tests were performed on aluminum cathodes that were prepared by drilling sample wells with various diameters (Ø), ranging from 0.50mm to 1.50mm, and depths ranging from 1.3mm to 4.3mm. C...
Source: Physics Procedia - October 26, 2017 Category: Physics Source Type: research
Acceptance Tests for AMS Radiocarbon Measurements at iThemba LABS, Gauteng, South Africa
Publication date: 2017 Source:Physics Procedia, Volume 90 Author(s): Vela L. Mbele, Simon M. Mullins, Stephan R. Winkler, Stephan Woodborne The accelerator mass spectrometer was commissioned recently at the iThemba LABS 6 MV tandem accelerator. Improvements in the vacuum system, requiring procurement of cryo-pumps and the reducing the tank pressure of the N2 + CO2 insulation gas mixture below the level used for IBA measurements, were necessary. This resulted in the reduction of the nitrogen background and improved the resolution of 14C from 14N background in the ionisation chamber. The nitrogen was leaking to the str...
Source: Physics Procedia - October 26, 2017 Category: Physics Source Type: research
Historic binnacle of 14C/12C concentration in Mexico City
Publication date: 2017 Source:Physics Procedia, Volume 90 Author(s): J.A. Flores, C. Solís, A. Huerta, M.E. Ortiz, M.G. Rodríguez-Ceja, J. Villanueva, E. Chávez The radiocarbon concentration is reduced in urban areas, generally due to high CO2 emissions derived from fossil fuels. In this paper, new Δ14C measurements in cellulose extracted from the growth rings of two trees over a 43-year period are presented. The first is in a zone with clean air (El Nayar, Durango, Mexico) and the second is from the Greater Mexico City area (Chapultepec). Data from El Nayar is consistent with that reported for Zone 2 of the N...
Source: Physics Procedia - October 26, 2017 Category: Physics Source Type: research
Single Pass Laser Welding with Multiple Spots to Join Four Sheets in a Butt-joint Configuration
Publication date: 2017 Source:Physics Procedia, Volume 89 Author(s): Morten Kristiansen, Klaus Schütt Hansen, Andreas Langbak, Sebastian Blegebrønd Johansen, Simon Borup Krempin, Mattias Døssing Hornum Laser keyhole welding is widely used in industry due to its large welding depth and low heat input. For some industrial cases it is necessary to widen the beam to cover the joint configuration, which instead results in a lower intensity and surface conduction welds. The introduction of the high-power single mode fiber laser makes it possible to deal with this problem, because the beam can be shaped into a pre-defi...
Source: Physics Procedia - September 26, 2017 Category: Physics Source Type: research
Application of Hybrid Laser arc Welding for the Joining of Large Offshore Steel Foundations
Publication date: 2017 Source:Physics Procedia, Volume 89 Author(s): Morten Kristiansen, Farhang Farrokhi, Ewa Kristiansen, Sigurd Villumsen To reduce the costs of the fabrication of offshore wind turbine foundations it is necessary to investigate new fabrication technologies. Hybrid laser arc welding is a potentially well-suited process for this because it requires less groove preparation to achieve deep weld penetration and lower heat input, compared to traditional arc welding. A skirt section of a suction bucket in 16mm steel was used as a case to investigate the hybrid laser-arc welding in order to demonstrate wh...
Source: Physics Procedia - September 26, 2017 Category: Physics Source Type: research
CYCLAM - Recycling by a Laser-driven Drop Jet from Waste that Feeds AM
Publication date: 2017 Source:Physics Procedia, Volume 89 Author(s): Alexander F.H. Kaplan, Ramiz S.M. Samarjy Additive manufacturing of metal parts is supplied by powder or wire. Manufacturing of this raw material causes additional costs and environmental impact. A new technique is proposed where the feeding directly originates from a metal sheet, which can even be waste. When cutting is done by laser-induced boiling, melt is continuously ejected downwards underneath the sheet. The ejected melt is deposited as a track on a substrate, enabling additive manufacturing by substrate movement along a desired path. The melt ...
Source: Physics Procedia - September 26, 2017 Category: Physics Source Type: research
Study of Strength Characteristics of Steel Specimens after Selective Laser Melting of Powder Materials 17-4PH, 316L, 321
Publication date: 2017 Source:Physics Procedia, Volume 89 Author(s): Anton Zhukov, Boris Barakhtin, Pavel Kuznetsov By the method of selective laser melting of powder materials nanostructured stainless steels 17-4PH, 316L, 321 were obtained. In all experiments the recorded hardness increase depending on the construction parameters. Obtained relationship of hardness increase with the carbon ratio, which explained by the chemical composition of the metal in the melting zone. It is suggested that the effect of hardness increase is associated with structural changes as to the formation and dissolution of hardening nanopha...
Source: Physics Procedia - September 26, 2017 Category: Physics Source Type: research
Effect of Alloying on the 316L and 321 Steels Samples Obtained by Selective Laser Melting
Publication date: 2017 Source:Physics Procedia, Volume 89 Author(s): Anton Zhukov, Artem Deev, Pavel Kuznetsov The main objective is to study the structure and mechanical properties of the samples based on 316L and 321 stainless steel powders with different particle size distribution, produced by selective laser melting. Despite the fact that the SLM technique involves almost complete melting of the metal powder particles, the difference in particle size and a fused layer thickness leads to differences in mechanical properties due to incomplete melting of large particles. Therefore, for each type of steel it's necessa...
Source: Physics Procedia - September 26, 2017 Category: Physics Source Type: research
Investigation of Cutting Quality of Remote DOE Laser Cutting in 0.5 mm Stainless Steel
Publication date: 2017 Source:Physics Procedia, Volume 89 Author(s): Sigurd Lazic Villumsen, Morten Kristiansen It has previously been shown that the stability of the remote fusion cutting (RFC) process can be increased by modifying the intensity profile of the laser by means of a diffractive optical element (DOE). This paper investigates the quality of remote DOE cutting (RDC) conducted with a 3kW single mode fiber laser in 0.5mm stainless steel. An automatic measurement system is used to investigate how the travel speed, focus offset and angle of incidence effect the kerf width and kerf variance. The study shows that...
Source: Physics Procedia - September 26, 2017 Category: Physics Source Type: research
Hybrid Laser-Arc Welding of the High-Strength Shipbuilding Steels: Equipment and Technology
Publication date: 2017 Source:Physics Procedia, Volume 89 Author(s): G. Turichin, M. Kuznetsov, I. Tsibulskiy, A. Firsova Hybrid laser-arc welding (HLAW) allows getting weld joints with thickness up to 35mm for one pass, provide good quality formation of joints, minimal thermal deformations, the productivity in 10 times more in comparison with arc welding. In addition, replacement arc welding to the HLAW allows economizing filler materials, shielding gas and consumable electricity more than 4 times. Therefore, HLAW is actually technology for basic engineering branches and especially for shipbuilding. The Institute of...
Source: Physics Procedia - September 26, 2017 Category: Physics Source Type: research
A New Method for Calculating the Error Term Used in 2D Feedback Control of Laser Forming
This study presents a new method for calculating the error between the target shape and the current shape. The method is based on geometrical information and uses a projection of the second derivative of the target geometry unto the current geometry. By comparing the projected second derivative with the second derivative of the current geometry, the error can be calculated. Once the error has been found, a feedback control strategy can be used to update the process parameters. The new method entails that the error can be calculated without having to solve the large scale mechanical FEM as part of the planning process. This...
Source: Physics Procedia - September 26, 2017 Category: Physics Source Type: research
Laser Welding of Coated Press-hardened Steel 22MnB5
Publication date: 2017 Source:Physics Procedia, Volume 89 Author(s): Jukka Siltanen, Ari Minkkinen, Sanna Järn The press-hardening process is widely used for steels that are used in the automotive industry. Using ultra-high-strength steels enables car manufacturers to build lighter, stronger, and safer vehicles at a reduced cost and generating lower CO2 emissions. In the study, laser welding properties of the coated hot stamped steel 22BMn5 were studied. A constant 900°C temperature was used to heat the steel plates, and two different furnace times were used in the press-hardening, being 300 and 740seconds. Some of ...
Source: Physics Procedia - September 26, 2017 Category: Physics Source Type: research
Thermal Impacts in Vibration-assisted Laser Deep Penetration Welding of Aluminum
Publication date: 2017 Source:Physics Procedia, Volume 89 Author(s): T. Radel Mechanical vibrations affect the nucleation and grain growth conditions during welding. In order to understand the vibration-induced influences on the grain formation conditions in laser beam welding of aluminum the thermal impacts of simultaneously applied vibrations are analyzed in this study. Therefore, laser deep penetration welding at vibration frequencies between 0.5 kHz and 5 kHz is investigated. Besides full penetration, partial penetration experiments were carried out. The results show that the thermal and absorption efficiencies are ...
Source: Physics Procedia - September 26, 2017 Category: Physics Source Type: research
Creating Learning Environment Connecting Engineering Design and 3D Printing
Publication date: 2017 Source:Physics Procedia, Volume 89 Author(s): Ari Pikkarainen, Antti Salminen, Heidi Piili Engineering education in modern days require continuous development in didactics, pedagogics and used practical methods. 3D printing provides excellent opportunity to connect different engineering areas into practice and produce learning by doing applications. The 3D-printing technology used in this study is FDM (Fused deposition modeling). FDM is the most used 3D-printing technology by commercial numbers at the moment and the qualities of the technology makes it popular especially in academic environments...
Source: Physics Procedia - September 26, 2017 Category: Physics Source Type: research
Preliminary Investigation on Life Cycle Inventory of Powder Bed Fusion of Stainless Steel
This study investigates effect of process sustainability in terms of raw material, energy and time consumption with PBF and CNC machining. The results of the experimental study indicated lower energy efficiency in the production process with PBF. This study revealed that specific energy consumption in PBF decreased when several components are built simultaneously than if they would be built individually. This is due to fact that energy consumption per part is lower. On the contrary, amount of energy needed to machine on part in case of CNC machining is lower when parts are done separately. (Source: Physics Procedia)
Source: Physics Procedia - September 26, 2017 Category: Physics Source Type: research
