The Experts below are selected from a list of 861 Experts worldwide ranked by ideXlab platform
Kazuhiro Nakata - One of the best experts on this subject based on the ideXlab platform.
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Laser Brazing of a dissimilar joint of austenitic stainless steel and pure copper
Welding International, 2015Co-Authors: Tetsuo Suga, Yasuoa Murai, Taizo Kobashi, Kunika Ueno, Minoru Shindo, Katsunori Kanno, Kazuhiro NakataAbstract:In many industries, there are applications that require the joining of stainless steel and copper components; therefore, the welding of dissimilar stainless steel/copper joints is a common process. For this investigation, the optimal Brazing conditions and suitable filler metals for Laser Brazing of stainless steel/copper lap joints were studied. Tensile shear force increases with increases in the Laser spot diameter or in the Laser irradiation angle, which is associated with increased bonding width; however, as bonding width approaches 2 mm, tensile shear force reaches a saturated value due to fracturing at the HAZ of the Cu base plate. In order to obtain joints with high tensile shear strength, Laser Brazing was optimized by using Cu–Si-based filler metal under the following conditions: Laser power, 4 kW; spot diameter, 3 mm; Laser irradiation angle, 80°; irradiation position shift, 0.6 mm; Brazing speed, 0.30 m/min; and filler metal feed speed, 0.30 min. Concerning filler metals, it was found that the ...
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Simulation of cracking phenomena during Laser Brazing of ceramics and cemented carbide
Science and Technology of Welding and Joining, 2014Co-Authors: Kimiaki Nagatsuka, Yoshihisa Sechi, Kazuhiro NakataAbstract:To investigate the mechanism of the occurrence of the microcracks produced in Laser Brazing of silicon carbide and cemented carbide using a silver–copper–titanium alloy as the filler metal, a numerical simulation for thermal cycle and thermal stress was performed using the finite element method. The Laser-irradiated area of the cemented carbide was heated selectively, and almost uniform temperature distribution in the filler metal was obtained. The tensile thermal stress in the silicon carbide appeared near the interface between the silicon carbide and the filler metal, and the maximum principle stress at about 400 K during the cooling process reached the fracture strength of the silicon carbide. This resulted in the formation of microcracks in the silicon carbide which was observed in the experiment.
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effect of composition of titanium in silver copper titanium braze alloy on dissimilar Laser Brazing of binder less cubic boron nitride and tungsten carbide
IOP Conference Series: Materials Science and Engineering, 2014Co-Authors: Yoshihisa Sechi, Kimiaki Nagatsuka, Kazuhiro NakataAbstract:Laser Brazing with Ti as an active element in silver-copper alloy braze metal has been carried out for binder-less cubic boron nitride and tungsten carbide, using silver-copper- titanium braze alloys with titanium content that varied between 0.28 mass% and 1.68 mass%. Observations of the interface using electron probe microanalysis and scanning acoustic microscopy show that efficient interface adhesion between binder-less cubic boron nitride and the silver-copper-titanium braze alloy was achieved for the braze with a titanium content of 0. 28 mass%.
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effect of ti content in ag cu ti activated filler metal on dissimilar joint formation of sialon and wc co alloy by Laser Brazing
Science and Technology of Welding and Joining, 2014Co-Authors: Kimiaki Nagatsuka, Yoshihisa Sechi, S Yoshida, Kazuhiro NakataAbstract:Laser Brazing was carried out for dissimilar joining of sialon and a WC–Co alloy. Eutectic type Ag–Cu alloys as filler metals with different Ti content ranging from 0 to 2·8 mass-% were used to investigate the effects of Ti on the interface structure and strength of the joint. The filler metal sheet was sandwiched between a sialon block and a WC–Co alloy plate, and a Laser beam was irradiated selectively on the WC–Co alloy plate. The brazed joint was obtained using the filler metal containing >0·3 mass-%Ti. TiN, Ti5Si3, and Cu4Ti layers were formed at the interface of sialon and brazed metal as compound layers. The shear strength of the brazed joint increased with increasing Ti content in the filler metal in the range 0·3–1·7 mass-%, reaching a maximum value of 106 MPa. However, the strength decreased when the Ti content became higher than 1·7 mass-%.
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interfacial microstructure and mechanical property of ti6al4v a6061 dissimilar joint by direct Laser Brazing without filler metal and groove
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013Co-Authors: Kazuhiro Nakata, Zhihua Song, Aiping Wu, Jinsun LiaoAbstract:Abstract Laser Brazing of Ti6Al4V and A6061-T6 alloys with 2 mm thickness was conducted by focusing Laser beam on aluminum alloy side, and the effect of Laser offset distance on microstructure and mechanical properties of the dissimilar butt joint was investigated. Laser offset has a great influence on the thickness of interfacial intermetallic compound (IMC) layer and the mechanical property of joint. The thickness of interfacial IMC layer is less than 500 nm, and the average tensile strength of the joint reaches 64% of aluminum base material strength, when suitable welding conditions are used. The interfacial IMC is TiAl 3 . The formation of interfacial IMC layer and its effect on mechanical property of the joint are discussed in the present study.
Kazutoshi Nishimoto - One of the best experts on this subject based on the ideXlab platform.
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Laser Brazing of TiAl intermetallic compound using precious Brazing filler metals
Welding in the World, 2015Co-Authors: Kazuyoshi Saida, Haruki Ohnishi, Kazutoshi NishimotoAbstract:The applicability of Laser Brazing technique to bonding of TiAl intermetallic compound was investigated. Five kinds of filler metals such as gold, sliver, palladium and titanium alloys were employed for Brazing. Diode Laser Brazing of TiAl intermetallic compound was carried out at Laser power 300–450 W, travelling velocity 3.0–5.0 mm/s and wire feeding speed 20.0 mm/s with shield gas (Ar) at flow rate 15 L/min. According to the preliminary investigation of the filler metal selection, the gold-silver-copper filler metal (BAu-12) was selected as the suitable Brazing filler metal for TiAl intermetallic compound. The filler metal did not completely penetrate and infiltrate the joint gap at lower heat input conditions, and the centreline cracking as well as serious erosion occurred in the braze metal at higher heat input conditions, while sound joints could be obtained by optimising processing parameters. The centreline cracking in the braze metal would be caused by the formation of brittle compounds attributed to the contamination (erosion) of the base metal into the filler metal. The theoretical approaches to the erosion and wetting/flowing phenomena during Laser Brazing process were made by the computer simulation. We customised the flow modelling software (FLOW-3D) to enable us to analyse the metal flow problem during Laser Brazing by coupled with the erosion behaviour. The simulations of the filler metal BAu-12 showed that it wetted/spread the base metals and infiltrated the joint gap with 0.5 mm when the Laser power was increased. However, it did not completely infiltrate the joint gap when the Brazing clearance was 0.3 mm. The amount of base metal erosion concurrently increased with an increase in the Laser power at any Brazing clearances. The computed wetting/flowing and erosion profiles in Laser braze joints were fairly consistent with the experimental ones. The joint strength of TiAl intermetallic compound with the filler metal BAu-12 at Laser power of 380 W attained to approx. 350 MPa being higher than 80 % of the base metal strength at any Brazing clearances between 0.3 and 0.5 mm.
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Fluxless Laser Brazing of aluminium alloy to galvanized steel using a tandem beam – dissimilar Laser Brazing of aluminium alloy and steels
Welding International, 2010Co-Authors: Kazuyoshi Saida, Haruki Ohnishi, Kazutoshi NishimotoAbstract:Tandem beam Brazing with aluminium filler metal (BA4047) was conducted in order to develop the fluxless Laser Brazing technique of aluminium alloy (AA6022) to galvanized steels (GA and GI steels). Laser powers of tandem beam and offset distance of preheating beam from the root to the steel base metal were varied. Sound braze beads could be obtained by optimizing the preheating and main beam powers under the offset distances of 0–1 mm. A small amount of zinc remained at the braze interface between galvanized steels and the braze metal. The reaction layer consisting of Fe–Al intermetallic compounds was also formed at the steel interface, and the thickness of reaction layer could be predicted during the Laser Brazing (thermal cycle) process based on the growth kinetics with the additivity rule. The metal flow analysis of the melted filler metal on joints revealed that wettability and spreadability of the filler metal on the GI steel joint were superior to those on the GA steel joint. The fracture strength of...
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fluxless Laser Brazing of aluminium alloy to galvanized steel using a tandem beam dissimilar Laser Brazing of aluminium alloy and steels
Welding International, 2010Co-Authors: Kazuyoshi Saida, Haruki Ohnishi, Kazutoshi NishimotoAbstract:Tandem beam Brazing with aluminium filler metal (BA4047) was conducted in order to develop the fluxless Laser Brazing technique of aluminium alloy (AA6022) to galvanized steels (GA and GI steels). Laser powers of tandem beam and offset distance of preheating beam from the root to the steel base metal were varied. Sound braze beads could be obtained by optimizing the preheating and main beam powers under the offset distances of 0–1 mm. A small amount of zinc remained at the braze interface between galvanized steels and the braze metal. The reaction layer consisting of Fe–Al intermetallic compounds was also formed at the steel interface, and the thickness of reaction layer could be predicted during the Laser Brazing (thermal cycle) process based on the growth kinetics with the additivity rule. The metal flow analysis of the melted filler metal on joints revealed that wettability and spreadability of the filler metal on the GI steel joint were superior to those on the GA steel joint. The fracture strength of...
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Computer Simulation of Wetting and Flowing Behaviors of Filler Metal during Laser Brazing Process
Materials Science Forum, 2009Co-Authors: Kazuyoshi Saida, Woo Hyun Song, Kazutoshi NishimotoAbstract:The wetting and flowing behaviors of the filler metal during Laser Brazing process were analyzed by the computer simulation. Two situations of the wetting and flowing during Laser Brazing were modelled, i.e., the metled Au-18%Ni and Ag-10%Pd filler metals on the butt joint of Inconel 600, and the melted Cu-8%Sn filler metal on the dissimilar butt joint of type 304 stainless steel to Cu. The filler metal droplet wetted and spread on the base metals and simultaneously infiltrated into the joint gap with the lapse of time. The Au-Ni and Ag-Pd filler metal infiltrated into the 0.3mm wide joint gap at the completion of Brazing even in the single beam Brazing. The Au-Ni filler metal did not infiltrate into the joint gap completely at the Brazing clearances of 0.1-0.2mm in the single beam Brazing, however, it could be filled up in the joint gap in the tandem beam Brazing. The Cu-Sn filler metal wetted on the both base metals of stainless steel and Cu and filled up the 0.3mm wide joint gap when the location of preheating beam deviated in 0.5mm to Cu substrate, however, it did not infiltrate into the joint gap completely at the deviation distance of preheating beam to Cu substrate being 1.0mm. It followed that the wetting and flowing behaviors of the filler metal during Laser Brazing process could be predicted by the computer simulation.
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Diode Laser Brazing of Heat-Resistant Alloys Using Tandem Beam
Materials Science Forum, 2009Co-Authors: Kazuyoshi Saida, Woo Hyun Song, Kazutoshi Nishimoto, Makoto ShiraiAbstract:The diode Laser Brazing of heat-resistant alloys with precious filler metals has been conducted using tandem beam which consisted of preheating beam and main Brazing beam. The 1mm thick Inconel 600 and A286 alloys were Laser-brazed with the 0.5mm diameter Au-18%Ni, Ag-10%Pd and Ag-21%Cu-25%Pd filler metals using a Brazing flux. The processing parameters of Laser power of tandem beam and Brazing clearance were varied. Sound butt joints could be obtained by using tandem beam with Laser powers of 200-400W/100-150W even at the narrow gap Brazing below 0.3mm where the melted filler metal did not infiltrate completely the joint gap by only using the main Brazing beam (single beam). The tensile strength of the brazed joint using Ag-Pd filler metal increased with decreasing Brazing clearance and attained about 70% of the base metal strength at Brazing clearance of 0.1mm, while those using Au-Ni and Ag-Cu-Pd filler metals were comparable to the base metal strength at any Brazing clearance between 0.1-1.5mm. The preheating during the tandem beam Brazing resulted in superior brazability at the narrow gap to wide gap Brazing because of the improvement in wetting/spreading and erosion esistance of melted filler metal by depressing the extremely high peak temperature and steep temperature distribution in the base metal.
Kazuyoshi Saida - One of the best experts on this subject based on the ideXlab platform.
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Dissimilar Laser Brazing of aluminum alloy and galvannealed steel and defect control using interlayer
Welding in the World, 2020Co-Authors: Tomo Ogura, Reiko Wakazono, Shotaro Yamashita, Kazuyoshi SaidaAbstract:The microstructure and tensile shear strength of the joint by Laser Brazing between dissimilar metals of aluminum alloy and galvannealed (GA) steel were investigated. A blowhole was formed by zinc vaporization during Laser Brazing; the tensile shear strength was significantly affected not by intermetallic compounds (IMCs) at the filler metal/GA steel interface but by the blowhole. The vaporization of zinc was suppressed, and the blowhole was controlled by inserting a Ti interlayer. The joint strength was improved through the suppression of blowhole, the thermal deformation of the Ti interlayer, and the increase in brazed filler metal thickness by optimizing the Brazing parameter. The hardness test revealed that fracture occurs preferentially in the brazed filler metal; however, as the brazed filler thickness increases, fracture begins to occur near the heat-affected zone of A5052 because the volume of filler metal increases. The maximum strength of the joint was 185 N/mm, which is about 73% of the joint efficiency to 254 N/mm of the A5052 base material, and the base material partly fractured.
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Dissimilar Metal Joining of A5052 Aluminum Alloy and AZ31 Magnesium Alloy Using Laser Brazing
Materials Science Forum, 2016Co-Authors: Tomo Ogura, Tetsuya Yokochi, Shunsuke Netsu, Kazuyoshi SaidaAbstract:The microstructure and mechanical properties of a joint produced by Laser Brazing between A5052 and AZ31 with AZ61, AZ91 and AZ125 filler metal was investigated. The effects of filler metals on joint characteristics are also discussed. Measurement of microstructural factors in the Laser brazed joint revealed that increasing the Laser power results in a decrease in the weld toe angle and an increase in the bead width, which indicates superior wettability. A high strength Laser brazed joint can be achieved through the combination of good wettability and a thin intermetallic layer produced by a Laser power of 590 W in a brazed joint with AZ125 filler metal Any further increase in power, however, results in a rapid increase in the thickness of the intermetallic compound (IMC) reaction layer. The superiority of the brazed joint with AZ125 filler metal is due to its lower melting point than that of AZ61 and AZ91 filler metal.
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Microstructure and mechanical properties in Laser Brazing of A5052/AZ31 dissimilar alloys
Welding in the World, 2016Co-Authors: Tomo Ogura, Tetsuya Yokochi, Shunsuke Netsu, Kazuyoshi SaidaAbstract:This investigation into the microstructure and mechanical properties of a joint produced by Laser Brazing between A5052 and AZ31 with AZ125 filler wire reveals that an increase in Laser power from 480 to 620 W reduces the weld toe angle and increases the bead width, resulting in an enhanced wettability. Any further increase in power, however, results in a rapid increase in the thickness of the intermetallic compound (IMC) reaction layer. The IMC layer consists of Mg_17Al_12 on the AZ125 side and Mg_2Al_3 on the A5052 side. The tensile shear strength is increased by using a Laser power of 480–600 W owing to the increased wettability, but is reduced when using a Laser power of 610–620 W owing to the thickness of the reaction layer and the presence of voids, which cause brittle fracture through the brazed filler metal.
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microstructure and mechanical properties in Laser Brazing of a5052 az31 dissimilar alloys
Welding in The World, 2016Co-Authors: Tomo Ogura, Tetsuya Yokochi, Shunsuke Netsu, Kazuyoshi SaidaAbstract:This investigation into the microstructure and mechanical properties of a joint produced by Laser Brazing between A5052 and AZ31 with AZ125 filler wire reveals that an increase in Laser power from 480 to 620 W reduces the weld toe angle and increases the bead width, resulting in an enhanced wettability. Any further increase in power, however, results in a rapid increase in the thickness of the intermetallic compound (IMC) reaction layer. The IMC layer consists of Mg17Al12 on the AZ125 side and Mg2Al3 on the A5052 side. The tensile shear strength is increased by using a Laser power of 480–600 W owing to the increased wettability, but is reduced when using a Laser power of 610–620 W owing to the thickness of the reaction layer and the presence of voids, which cause brittle fracture through the brazed filler metal.
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Laser Brazing of TiAl intermetallic compound using precious Brazing filler metals
Welding in the World, 2015Co-Authors: Kazuyoshi Saida, Haruki Ohnishi, Kazutoshi NishimotoAbstract:The applicability of Laser Brazing technique to bonding of TiAl intermetallic compound was investigated. Five kinds of filler metals such as gold, sliver, palladium and titanium alloys were employed for Brazing. Diode Laser Brazing of TiAl intermetallic compound was carried out at Laser power 300–450 W, travelling velocity 3.0–5.0 mm/s and wire feeding speed 20.0 mm/s with shield gas (Ar) at flow rate 15 L/min. According to the preliminary investigation of the filler metal selection, the gold-silver-copper filler metal (BAu-12) was selected as the suitable Brazing filler metal for TiAl intermetallic compound. The filler metal did not completely penetrate and infiltrate the joint gap at lower heat input conditions, and the centreline cracking as well as serious erosion occurred in the braze metal at higher heat input conditions, while sound joints could be obtained by optimising processing parameters. The centreline cracking in the braze metal would be caused by the formation of brittle compounds attributed to the contamination (erosion) of the base metal into the filler metal. The theoretical approaches to the erosion and wetting/flowing phenomena during Laser Brazing process were made by the computer simulation. We customised the flow modelling software (FLOW-3D) to enable us to analyse the metal flow problem during Laser Brazing by coupled with the erosion behaviour. The simulations of the filler metal BAu-12 showed that it wetted/spread the base metals and infiltrated the joint gap with 0.5 mm when the Laser power was increased. However, it did not completely infiltrate the joint gap when the Brazing clearance was 0.3 mm. The amount of base metal erosion concurrently increased with an increase in the Laser power at any Brazing clearances. The computed wetting/flowing and erosion profiles in Laser braze joints were fairly consistent with the experimental ones. The joint strength of TiAl intermetallic compound with the filler metal BAu-12 at Laser power of 380 W attained to approx. 350 MPa being higher than 80 % of the base metal strength at any Brazing clearances between 0.3 and 0.5 mm.
Klaus Dilger - One of the best experts on this subject based on the ideXlab platform.
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Three-beam Laser Brazing of zinc-coated steel
The International Journal of Advanced Manufacturing Technology, 2017Co-Authors: Wilfried Reimann, Martin Goede, Michael Dobler, Michael Schmidt, Klaus DilgerAbstract:This work investigates the use of a trifocal Laser intensity distribution to control the applied heat profile for Laser Brazing of hot-dip galvanized steel. Process analysis of conventional monofocal Brazing processes showed that spatter and other process disruptions mainly originate from zinc dissolution and evaporation at the wetting line. In order to increase process stability and seam quality, a trifocal Brazing method was developed and applied for Brazing experiments. A transient three-dimensional model of the Brazing processes shows a shift of the achieved temperature distribution and thus a separated evaporation of the zinc coating prior to the wetting with molten CuSi3 brass. The influence of the adjusted intensity distribution in the process area was analyzed with high-speed video imaging, thermal imaging, and metallographic analysis of the seam properties. The experimental analysis confirms that during trifocal Brazing, a local zinc evaporation takes place prior to the spreading of the molten filler metal. As a result, a less turbulent processing zone and a superior seam quality are attained.
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Influence of different zinc coatings on Laser Brazing of galvanized steel
Journal of Materials Processing Technology, 2017Co-Authors: Wolfgang Reimann, Simon Pfriem, Thorge Hammer, Michael Ungers, Dieter Päthe, Klaus DilgerAbstract:The use of hot-dip galvanized steel sheets as base material for Laser Brazing led to the formation of spatter and a wavy appearance of the seam. High-speed imaging revealed that spatter formation occurs mainly close to the seam edges. Thermography of the Brazing process showed that the type of zinc coating affects the resulting temperature distribution and thereby changes the conditions for the zinc evaporation. Higher temperatures were observed at the seam edges on electro galvanized and phosphated substrates. The cross sections and the process analysis indicate that the zinc evaporation on electro galvanized substrates takes place prior to the wetting with the molten filler material. On the other hand a merely partial evaporation of the zinc coating and the accumulation of zinc at the seam edges takes place during the Brazing of hot-dip galvanized substrates. The formation of spatter is caused by the zinc dissolution and the subsequent evaporation of the zinc rich alloy at the seam edges. The optical properties of the base material are considered to be a crucial factor for the temperature distribution and the resulting zinc evaporation. Brazing trials on hot-dip galvanized and phosphated substrates, which show a reflectance similar to electro galvanized and phosphated specimens, confirm this assumption, as no spatter formation at the seam edge was observed.
Frank Vollertsen - One of the best experts on this subject based on the ideXlab platform.
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Novel Approach to Increase the Energy-related Process Efficiency and Performance of Laser Brazing
Physics Procedia, 2016Co-Authors: C. Mittelstädt, Thomas Seefeld, Tim Radel, Frank VollertsenAbstract:Abstract Although Laser Brazing is well established, the energy-related efficiency of this joining method is quite low. That is because of low absorptivity of solid-state Laser radiation, especially when copper base braze metals are used. Conventionally the Laser beam is set close to the vertical axis and the filler wire is delivered under a flat angle. Therefore, the most of the utilized Laser power is reflected and thus left unexploited. To address this situation an alternative processing concept for Laser Brazing, where the Laser beam is leading the filler wire, has been investigated intending to make use of reflected shares of the Laser radiation. Process monitoring shows, that the reflection of the Laser beam can be used purposefully to preheat the substrate which is supporting the wetting and furthermore increasing the efficiency of the process. Experiments address a standard application from the automotive industry joining zinc coated steels using CuSi3Mn1 filler wire. Feasibility of the alternative processing concept is demonstrated, showing that higher processing speeds can be attained, reducing the required energy per unit length while maintaining joint properties.
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Two-beam Laser Brazing of Thin Sheet Steel for Automotive Industry Using Cu-base Filler Material☆
Physics Procedia, 2014Co-Authors: C. Mittelstädt, Thomas Seefeld, Daniel Reitemeyer, Frank VollertsenAbstract:Abstract This work shows the potential of two-beam Laser Brazing for joining both Zn-coated steel and 22MnB5. Brazing of Zn-coated steel sheets using Cu-Si filler wire is already state of the art in car manufacturing. New press-hardened steels like 22MnB5 are more and more used in automotive industry, offering high potential to save costs and improve structural properties (reduced weight / higher stiffness). However, for joining of these ultra-high strength steels investigations are mandatory. In this paper, a novel approach using a two-beam Laser Brazing process and Cu-base filler material is presented. The use of Cu-base filler material leads to a reduced heat input, compared to currently applied welding processes, which may result in benefits concerning distortion, post processing and tensile strength of the joint. Reliable processing at desired high speeds is attained by means of Laser-preheating. High feed rates prevent significant diffusion of copper into the base material.
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the role of zinc layer during wetting of aluminium on zinc coated steel in Laser Brazing and welding
Physics Procedia, 2014Co-Authors: M Gatzen, Claus Thomy, Tim Radel, Frank VollertsenAbstract:Abstract The zinc layer of zinc-coated steel is known to be a crucial factor for the spreading of liquid aluminium on the coated surface. For industrial Brazing and welding processes these zinc-coatings enable a fluxless joining between aluminium and steel in many cases. Yet, the reason for the beneficial effect of the zinc to the wetting process is not completely understood. Fundamental investigations on the wetting behaviour of single aluminium droplets on different zinc-coated steel surfaces have revealed a distinct difference between coated surfaces at room temperature and at elevated temperature regarding the influence of different coating thicknesses. In this paper the case of continuous Laser Brazing and welding processes of aluminium and commercial galvanized zinc-coated steel sheets are presented. It is shown that in the case of bead-on-plate Laser beam Brazing, the coating thickness has a measureable effect on the resulting wetting angle and length but does not have a significant impact in case of overlap Laser beam welding. This might be linked to different heat transfer conditions. The results also strongly indicate that proper initialbreakup of oxide layers is still required to accomplish good wetting on zinc-coated surfaces.
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Laser Brazing of Aluminum with a New Filler Wire AlZn13Si10Cu4
Physics Procedia, 2013Co-Authors: Z. Tang, Thomas Seefeld, Frank VollertsenAbstract:Abstract Laser Brazing processes of aluminum with both single beam and double beam techniques were developed using a new AlZn13Si10Cu4 filler wire which has a lower solidification range comparing to normal AlSi12 filler wire and the base material. Brazing experiments on both bead on plate and flange joints showed that the new wire has a very good wettability on the aluminum samples. Comparing to the AlSi12 wire one needs a lower heat input (in some cases 73% less heat input) for joining the same samples with the new filler wire and reaches a high hardness value in the joint. In addition, Brazing with double beam technique showed its potential to increase the joint quality.
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Laser Brazing of high strength steels
International Congress on Applications of Lasers & Electro-Optics, 2007Co-Authors: Andreas Wirth, H. Laukant, Claus Thomy, U. Glatzel, Frank VollertsenAbstract:The application of high strength steels demands for joining methods for these steels. As welding may be difficult for some of the steels due to a detrimental effect of weld metal and the heat affected zone on the mechanical properties of the joint, Brazing of these steels might be a better solution.Therefore, Laser Brazing of high-strength steels is regarded. Besides the brazeability of high strength steels such as TRIP800, the possibility of Brazing these steels to low alloyed steels (DC05) with or without zinc coatings is discussed.The heat affected zones (HAZ) of the joints were analysed and the change of hardness in the HAZ was measured. It was established that the hardness of the steels is increased within the HAZ for all steels considered. Even an intermetallic phase seam was detected in the steel-filler metal interface. These results are correlated with the strength of the joint and cracking behaviour. This behaviour was experimentally verified by static fracture tests. So the influence of the intermetallic phases and the HAZ on the strength of the joint is better understandable. The results will contribute to an improved understanding of the brazeability of high strength steels.The application of high strength steels demands for joining methods for these steels. As welding may be difficult for some of the steels due to a detrimental effect of weld metal and the heat affected zone on the mechanical properties of the joint, Brazing of these steels might be a better solution.Therefore, Laser Brazing of high-strength steels is regarded. Besides the brazeability of high strength steels such as TRIP800, the possibility of Brazing these steels to low alloyed steels (DC05) with or without zinc coatings is discussed.The heat affected zones (HAZ) of the joints were analysed and the change of hardness in the HAZ was measured. It was established that the hardness of the steels is increased within the HAZ for all steels considered. Even an intermetallic phase seam was detected in the steel-filler metal interface. These results are correlated with the strength of the joint and cracking behaviour. This behaviour was experimentally verified by static fracture tests. So the influence of the inte...
