TY - CONF A1 - Cross, Carl Edward A1 - Böllinghaus, Thomas T1 - The Effect of Restraint on weld Solidification Cracking in Aluminium T2 - IIW Conference 2005 CY - Prague, Czech Republic PY - 2005 PB - IIW CY - Prag AN - OPUS4-11857 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Coniglio, Nicolas A1 - Cross, Carl Edward ED - Jürgen Hirsch, ED - Skrotzki, Birgit ED - Günter Gottstein, T1 - Effect of Cooling Rate and Silicon Content on Solidification Path and Phase Constituents in 6060 Aluminium Castings and Weld Metal T2 - 11th International Conference on Aluminium Alloys (ICAA 11) CY - Aachen, Germany DA - 2008-09-22 KW - Weld Metal Microstructure KW - Cast Microstructure KW - Al-Mg-Si Alloy System KW - 6060 Aluminium Alloy KW - 4043 Filler Alloy KW - Silicon Content KW - Cooling Rate KW - Phase Constituents KW - Solidification Path PY - 2008 SN - 978-3-527-32367-8 VL - 2 SP - 1889 EP - 1893 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-18309 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Coniglio, Nicolas A1 - Cross, Carl Edward A1 - Michael, Thomas A1 - Lammers, Marco T1 - Defining a critical weld dilution to avoid solidification cracking in aluminum N2 - Al-Mg-Si alloys are known to be highly susceptible to solidification cracking except when using an appropriate filler metal (e.g., 4343 or 5356), although the amount of dilution required to avoid cracking has never been a well-defined quantity. The aim of the present study is to determine a relationship between filler metal dilution, local strain rate conditions, and cracking susceptibility. Making use of the controlled tensile weldability (CTW) test and local strain extensometer measurements, a boundary has been established between crack and non-crack conditions for different local strain rates and dilution amounts, holding all other welding parameters constant. This boundary, presented in the form of critical strain rate-dilution map, defines the critical amount of 4043 filler metal required to avoid solidification cracking when arc welding 6060 aluminium, depending upon local strain rate. T2 - Light Alloy Seminar CY - Clausthal, Germany DA - 2006-11-20 KW - Dilution KW - Solidification Cracking KW - Al-Mg-Si Alloys KW - 6060 Aluminium KW - Arc Welding KW - Strain Rate KW - 4043 Filler Dilution PY - 2008 SN - 0043-2296 SN - 0096-7629 VL - 87 IS - 8 SP - 237 EP - 247 PB - American Welding Society CY - New York, NY AN - OPUS4-18311 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Coniglio, Nicolas A1 - Cross, Carl Edward ED - Carl E. Cross, ED - John C. Lippold, ED - Böllinghaus, T. ED - Herold, H. T1 - Weld parameter and minor element effects on solidification crack initiation in Aluminium N2 - Earlier work has established that a critical amount of 4043 filler is required to avoid solidification cracking when arc-welding 6060 aluminium, depending upon local strain conditions. For example, when the mushy zone behind the weld pool experiences a tensile strain from combined thermal and shrinkage stresses, the possibility exists for crack initiation. For a greater rate of strain, it has been determined that a greater 4043 dilution (i.e. higher weld metal silicon content) is required to avoid crack initiation. Making use of the Controlled Tensile Weldability (CTW) test and local strain extensometer measurements, a boundary has been established between crack and no-crack conditions for different local strain rates and filler dilutions, holding all other welding parameters constant. Using this established boundary as a line of reference, additional parameters have now been examined and their influence on cracking has been characterized. These parameter influences have included studies of weld travel speed, weld pool contaminants (Fe, O, and H), and grain refiner additions (TiAl3 + Boron). Each parameter has been independently varied and its effect on cracking susceptibility quantified in terms of a critical strain rate required to initiate cracking for a given 4043 filler dilution. T2 - Hot cracking phenomena in welds II CY - Berlin, Germany DA - 2006-03-05 KW - Aluminium Alloys KW - Solidification Cracking KW - Weld Defect KW - Hot Cracking KW - Crack Initiation KW - Critical Strain Rate KW - Parameter Effects KW - Minor Elements PY - 2008 SN - 978-3-540-78627-6 SP - 277 EP - 310 PB - Springer CY - Berlin AN - OPUS4-18323 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Cross, Carl Edward A1 - Ben-Hamu, G. A1 - Eliezer, D. A1 - Xu, Ping ED - Kainer, K. U. T1 - Corrosion-fatigue of AZ31 wrought Magnesium weldments T2 - 7th International conference on magnesium alloys and their applications CY - Dresden, Germany DA - 2006-09-06 KW - AZ31 Magnesium Alloy KW - Arc Weld KW - Corrosion Fatigue KW - Salt Water PY - 2008 SN - 978-3-527-31764-6 SP - 727 EP - 733 PB - Wiley-VCH AN - OPUS4-18313 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Cross, Carl Edward A1 - Coniglio, Nicolas ED - Carl E. Cross, ED - John C. Lippold, ED - Böllinghaus, T. ED - Herold, H. T1 - Weld solidification cracking: critical conditions for crack initiation and growth N2 - A perspective will be given that outlines important considerations in evaluating and predicting weldability. An examination will be made of the local conditions necessary for solidifications crack initiation and growth in a weld. This will be done in light of two prominent thermo-mechanical approaches involving critical strain and critical strain rate. Critical conditions will be identified based upon values available in the literature. Methods used to measure strain and strain rate will be compared. The interpretation of crack lenght measurements commonly used to quantify weldability will be questioned, based upon our current understanding of the problem. Complications and problem areas needing better definition will be identified and discussed, including strain distribution in the mushy zone, segregation at grain boundaries, effect of impurities, and effect of cooling rate on solidification path. Finally, a suggestion will be made for a new approach to weld development using in-situ strain rate measurements and new composition-strain rate maps that define the boundary between crack an no-crack conditions. T2 - Hot cracking phenomena in welds II CY - Berlin, Germany DA - 2007-03-05 KW - Solidification Cracking KW - Hot Cracking KW - Crack Initiation KW - Crack Growth KW - Critical Strain KW - Critical Strain Rate KW - Weldability Testing KW - Crack Prediction PY - 2008 SN - 978-3-540-78627-6 SP - 39 EP - 58 PB - Springer CY - Berlin AN - OPUS4-18319 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - McInerney, T.-J. A1 - Madigan, R.B. A1 - Xu, Ping A1 - Cross, Carl Edward ED - Stan A. David, ED - Tarasankar DebRoy, ED - John C. Lippold, ED - Herschel B. Smartt, ED - John M. Vitek, T1 - Achieving grain refinement through weld pool oscillation T2 - 7th International Conference on Trends in Welding Research CY - Pine Mountain, GA, USA DA - 2005-05-16 KW - Aluminium Alloy KW - Grain Refinement KW - Weld Pool Oscillation KW - Frequency Amplitude Range KW - Alloy 2219 PY - 2006 SN - 978-0-87170-842-7 SP - 17 EP - 22 PB - ASM International CY - Materials Park, Ohio AN - OPUS4-18040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kannengießer, Thomas A1 - Cross, Carl Edward T1 - Effect of tack placement on local weld displacement and solidification cracking during arc welding of aluminium alloy 6083 T2 - 1st South-east Asia International Institute of Welding Congress "Welding in South-East-Asia: A Challenge for the Future" CY - Bangkok, Thailand DA - 2006-11-21 KW - Heißriss KW - Aluminiumlegierung KW - Erstarrungsriss KW - Heften PY - 2006 SP - 480 EP - 491 (Paper No. 52) PB - Welding Institute of Thailand CY - Bangkok AN - OPUS4-14218 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Coniglio, Nicolas A1 - Cross, Carl Edward T1 - Characterization of solidification path for Aluminium 6060 weld metal with variable 4043 filler dilution N2 - Aluminium alloy 6060 is typical of a family of Al-Mg-Si extrusion alloys, which are considered weldable only when using an appropriate filler alloy such as 4043 (Al-5Si) or 5356 (Al-5Mg). This study concerns the thermal analysis and solidification path determination of aluminium alloy 6060 diluted with variable amounts of 4043. Casting of controlled mixtures of alloys 6060 and 4043 was used to simulate different weld dilutions in order to facilitate thermal analysis. Thermal analysis and metallography were applied in order to reveal solidification reactions and phases, and allow calculation of solid fraction versus temperature curves. Although the liquidus temperature was little affected, different phases formed with increased 4043 dilution, with a trend toward lower temperature reactions and a larger fraction interdendritic constituent. KW - Aluminium alloys KW - Light metals KW - Solidification cracking KW - Cracking KW - Defects KW - Hot cracking KW - Analysis techniques KW - Cooling KW - Cooling rate KW - Temperature KW - Practical investigations KW - Microstructure KW - Dilution KW - Reference lists PY - 2006 UR - http://www.iiw-iis.org/ SN - 0043-2288 SN - 1878-6669 VL - 50 IS - 11/12 SP - 14 EP - 23 PB - Springer CY - Oxford AN - OPUS4-14219 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cross, Carl Edward A1 - Böllinghaus, Thomas T1 - The Effect of Restraint on weld Solidification Cracking in Aluminium KW - Aluminium alloys KW - Light metals KW - Solidification cracking KW - Cracking KW - Defects KW - Hot cracking KW - Crack initiation KW - Strain KW - Restraint PY - 2006 SN - 0043-2288 SN - 1878-6669 VL - 50 IS - 11/12 SP - 51 EP - 54 PB - Springer CY - Oxford AN - OPUS4-14220 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eliezer, Dan A1 - Tal-Gutelmacher, E. A1 - Cross, Carl Edward A1 - Böllinghaus, Thomas T1 - Hydrogen trapping in beta-21S titanium alloy N2 - Different characteristics of hydrogen's absorption/desorption behavior and trapping in ß-21S titanium alloy are studied by means of thermal desorption spectroscopy (TDS). Spectra analysis is supported by data from variety of other experimental techniques, such as LECO hydrogen determinator, XRD and microstructure investigations by means of optic and electronic microscopy. In contrast to many past considerations, the complex process of hydrogen evolution has been found to be significantly affected by the way hydrogen introduction into the alloy. The different trapping sites, as well as phase transformations, have to be considered as the reasons for the different hydrogen evolution behavior. KW - Titanium alloys KW - Hydrogen absorption KW - Hydrogen desorption KW - Thermally activated processes KW - Thermal desorption spectroscopy (TDS) PY - 2006 DO - https://doi.org/10.1016/j.msea.2006.01.067 SN - 0921-5093 SN - 1873-4936 VL - 421 IS - 1-2 SP - 200 EP - 207 PB - Elsevier CY - Amsterdam AN - OPUS4-14423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eliezer, Dan A1 - Tal-Gutelmacher, E. A1 - Kannengießer, Thomas A1 - Cross, Carl Edward A1 - Böllinghaus, Thomas T1 - The effects of high fugacity and internal hydrogen on beta-21S titanium alloy T2 - EUROCORR 2005 CY - Lisbon, Portugal DA - 2005-09-04 KW - Titanium alloys KW - Beta-21S KW - Hydrogen desorption KW - Thermal Desorption Spectroscopy (TDS) PY - 2005 SP - 1 EP - 9 PB - Fundação para a Ciência e a Tecnologia CY - Lisbon AN - OPUS4-14451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Eliezer, Dan A1 - Hamu, G.B. A1 - Cross, Carl Edward A1 - Böllinghaus, Thomas ED - Galloway, T. T1 - Effect of grain refinement on the strength and corrosion of AZ31 magnesium alloy following severe plastic deformation N2 - Gas tungsten arc welds made on wrought magnesium AZ31 plate have been characterized for corrosion in saline solution (3.5% NaCl). Microstructural changes induced by the welding process resulted in different environmental behaviour of each zone (BM-base metal, HAZ-heat affected zone and FZ-fusion zone). The faster kinetics of corrosion in FZ and especially HAZ are attributed to (a) the coarse microstructure, consisting of large grains, and (b) very small amounts of ß-phase in the grain boundaries. Also, hardness traverses have shown that these zones are weaker than the base metal. Based on the significant effect of grain size on strength in magnesium alloys, the weld metal grains have been systematically refined using controlled oscillation during welding, and by adding a grain refiner to the weld pool. Detailed microstructure analyses have been carried out and the relationships between corrosion behaviour, mechanical properties and microstructure (grain refinement and second-phases formation) are highlighted. T2 - 135th Annual Meeting of the Minerals, Metals & Materials Society CY - San Antonio, TX, USA DA - 2006-03-12 PY - 2006 SN - 978-0-87339-619-6 VL - 135 SP - 1 EP - 4 PB - TMS, the Minerals, Metals & Materials Society CY - Warrendale AN - OPUS4-14452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eliezer, Dan A1 - Tal-Gutelmacher, E. A1 - Cross, Carl Edward A1 - Böllinghaus, Thomas ED - Gdoutos, E. T1 - Irreversible Hydrogen Trapping in Welded Beta-21S Titanium Alloy T2 - 16th European Conference of Fracture CY - Alexandroupoli, Greece DA - 2006-07-03 KW - Titanium alloys KW - Beta-21S KW - Hydrogen desorption KW - Thermal Desorption Spectroscopy (TDS) PY - 2006 VL - 16 IS - 803 SP - 1 EP - 8 CY - Alexandroupolis AN - OPUS4-14453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eliezer, Dan A1 - Tal-Gutelmacher, E. A1 - Cross, Carl Edward A1 - Böllinghaus, Thomas T1 - Hydrogen absorption and desorption in a duplex-annealed Ti-6Al-4V alloy during exposure to different hydrogen-containing environments N2 - Based on its excellent combination of a high strength/weight ratio and good corrosion behavior, Ti–6Al–4V alloy is ranked among the most important advanced materials for a variety of industrial applications. However, in many of these technological applications, this alloy is exposed to environments which can act as sources of hydrogen, and severe problems may arise based on its susceptibility to hydrogen embrittlement. Even small hydrogen concentrations might lead to failure. Consequently, a comprehensive knowledge of hydrogen's absorption/desorption behavior and interactions between hydrogen and different microstructural features is necessary to better understand the desorption and trapping mechanisms, the types of the trap sites, and the trapped hydrogen content, in order to determine the safe service conditions of this alloy in the industry. In this paper, different characteristics of hydrogen's absorption/desorption behavior and trapping in a duplex-annealed Ti–6Al–4V alloy are studied by means of thermal desorption spectroscopy (TDS). Spectra analysis is supported by data from a variety of other experimental techniques, such as LECO hydrogen determinator, XRD and microstructure investigations by means of optical and electron microscopy. Hydrogen evolution is found to be a very complex process, being affected by the way hydrogen was initially introduced to the alloy, the phase transformations that may occur during the thermal analysis and the presence of potential trapping sites. KW - Titanium alloys KW - Hydrogen absorption KW - Hydrogen desorption KW - Ti-6Al-4V KW - Thermal desorption spectroscopy (TDS) PY - 2006 DO - https://doi.org/10.1016/j.msea.2006.06.088 SN - 0921-5093 SN - 1873-4936 VL - 433 IS - 1-2 SP - 298 EP - 304 PB - Elsevier CY - Amsterdam AN - OPUS4-14484 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ben-Hamu, G. A1 - Eliezer, Dan A1 - Cross, Carl Edward A1 - Böllinghaus, Thomas T1 - Microstructure and Corrosion Resistance of TIG Welded AZ31B Magnesium Sheet T2 - 2nd International Conference on Magnesium CY - Beijing, China DA - 2006-06-25 KW - AZ31B KW - TIG welded KW - Microstructure KW - Corrosion behavior PY - 2006 VL - 2 IS - A-044 SP - 1 EP - 8 CY - Beijing AN - OPUS4-14486 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cross, Carl Edward A1 - Eliezer, Dan A1 - Böllinghaus, Thomas T1 - The Role of Hydrogen in Titanium Alloy Weldments T2 - Titanium Conference 2006 CY - San Diego, CA, USA DA - 2006-10-01 PY - 2006 VL - 22 SP - 1 EP - 9 CY - San Diego AN - OPUS4-14488 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ben-Hamu, G. A1 - Eliezer, D. A1 - Cross, Carl Edward A1 - Böllinghaus, Thomas T1 - The relation between microstructure and corrosion behavior of GTA welded AZ31B magnesium sheet N2 - Welding of AZ31B magnesium alloy was carried out using gas-tungsten arc (GTA) welding. The microstructure and the corrosion behavior of welded magnesium AZ31B alloy were investigated. ac and dc polarization tests were carried out on the welded Mg sheet. The microstructure was examined using optical and electron microscopy (TEM and SEM), X-ray analysis and EDS. Scanning Kelvin probe force microscopy (SKPFM) was used in order to measure the Volta potential of different phases relative to the matrix. The results showed that the GTA process effected both the microstructure and the corrosion behavior. These results can be explained by the effects of the process on microstructure of AZ31B Mg alloy sheet such as grain size and precipitates caused by the change in precipitation and recrystallization behavior. KW - AZ31B KW - GTA weld KW - Microstructure KW - Corrosion behavior KW - SKPFM KW - Intermetallics PY - 2007 DO - https://doi.org/10.1016/j.msea.2006.12.122 SN - 0921-5093 SN - 1873-4936 VL - 452/453 SP - 210 EP - 218 PB - Elsevier CY - Amsterdam AN - OPUS4-15459 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Coniglio, N. A1 - Cross, Carl Edward A1 - Dörfel, Ilona A1 - Österle, Werner T1 - Phase formation in 6060/4043 aluminium weld solidification N2 - Weld metal microstructure for alloy 6060 aluminum welds, made using the gas-tungsten arc process and alloy 4043 filler metal, has been characterized using optical metallography, EPMA microprobe analysis, SEM/EBSD and STEM/EDX electron microscopy, and single-sensor differential thermal analysis (SS-DTA). In addition, alloy 6060 castings were solidified at variable cooling rates approaching that of welding, to provide a reference for comparison with weld microstructure. It was found that a major change in cast microstructure occurs at cooling rates higher than 27 K/s resulting in a structure similar to that observed in weld metal. Rapid cooling is believed to favor low temperature solidification reactions that normally would be achieved only at higher silicon content. Accordingly, additions of 4043 filler metal that increase the weld metal silicon content have only limited affect on weld solidification range and microstructure. This has direct implications regarding how 4043 filler additions improve weldability and weld quality. KW - 6060 aluminium KW - GTA weld KW - Weld metal microstructure KW - Cooling rate KW - Scanning TEM KW - Thermal analysis PY - 2009 DO - https://doi.org/10.1016/j.msea.2009.03.087 SN - 0921-5093 SN - 1873-4936 VL - 517 IS - 1-2 SP - 321 EP - 327 PB - Elsevier CY - Amsterdam AN - OPUS4-20625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mousavi, M.G. A1 - Cross, Carl Edward A1 - Grong, O. T1 - The effect of high-temperature eutectic-forming impurities on aluminium 7108 weldability KW - 7108 aluminium KW - Iron impurity KW - Weldability KW - High temperature eutectic KW - Sc, Mn, Fe, Co, and Ni KW - Alloy 7108 KW - Eutectic KW - Interdendritic fluid flow KW - Grain size KW - Circular patch test (CPT) PY - 2009 SN - 0043-2296 SN - 0096-7629 VL - 88 SP - 104-s - 110-s PB - American Welding Society CY - New York, NY AN - OPUS4-20626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Coniglio, N. A1 - Cross, Carl Edward T1 - Mechanisms for solidification crack initiation and growth in aluminium welding N2 - In the present work, mechanisms are proposed for solidification crack initiation and growth in aluminum alloy 6060 arc welds. Calculations for an interdendritic liquid pressure drop, made using the Rappaz-Drezet-Gremaud (RDG) model, demonstrate that cavitation as a liquid fracture mechanism is not likely to occur except at elevated levels of hydrogen content. Instead, a porosity-based crack initiation model has been developed based upon pore stability criteria, assuming that gas pores expand from pre-existing nuclei. Crack initiation is taken to occur when stable pores form within the coherent dendrite region, depending upon hydrogen content. Following initiation, crack growth is modeled using a mass balance approach, controlled by local strain rate conditions. The critical grain boundary liquid deformation rate needed for solidification crack growth has been determined for a weld made with a 16 pct 4043 filler addition, based upon the local strain rate measurement and a simplified strain rate partitioning model. Combined models show that hydrogen and strain rate control crack initiation and growth, respectively. A hypothetical hydrogen strain rate map is presented, defining conceptually the combined conditions needed for cracking and porosity. KW - 6060 aluminium KW - Weld solidification cracking KW - Crack initiation/growth mechanisms KW - Transverse strain rate KW - Porosity formation PY - 2009 DO - https://doi.org/10.1007/s11661-009-9964-4 SN - 1073-5623 SN - 1543-1940 VL - 40 IS - 11 SP - 2718 EP - 2728 PB - The Minerals, Metals and Materials Society CY - Warrendale AN - OPUS4-20627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ben-Hamu, G. A1 - Eliezer, D. A1 - Cross, Carl Edward A1 - Böllinghaus, Thomas T1 - Volta potential of second phase particles in TIG welded AZ31 magnesium sheet T2 - EUROCORR 2006 CY - Maastricht, The Netherlands DA - 2006-09-25 KW - TIG welding KW - AZ31 Magnesium Alloy KW - Corrosion behavior PY - 2006 N1 - Serientitel: EFC-Event – Series title: EFC-Event IS - 280 SP - 1 EP - 10 PB - European Federation of Corrosion CY - Maastricht AN - OPUS4-22134 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Cross, Carl Edward A1 - Coniglio, Nicolas A1 - Schempp, Philipp A1 - Mousavi, M.G. ED - Lippold, J. ED - Böllinghaus, T. ED - Cross, C.E. ED - et al., T1 - Critical conditions for weld solidification crack growth N2 - The occurrence of solidification cracking during welding remains a little understood phenomenon, in spite of extensive studies and tests performed to evaluate and compare the relative weldability of many different alloys. From an approach often adopted in the welding community attributed to Prokhorov, solidification cracks are believed to form when a critical tensile strain is exceeded, specific to the alloy, assuming that the mushy-zone has limited ductility. Tensile stresses and strains normally form behind a moving weld pool as a result of solidification shrinkage and thermal contraction, as influenced by welding parameters and the degree of restraint. KW - Solidification cracking KW - Aluminium alloy KW - Crack growth KW - Strain rate model PY - 2011 SN - 978-3-642-16863-5 DO - https://doi.org/10.1007/978-3-642-16864-2_2 IS - Part 2 SP - 25 EP - 41 PB - Springer CY - Berlin, Heidelberg AN - OPUS4-23846 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schempp, Philipp A1 - Cross, Carl Edward A1 - Schwenk, Christopher A1 - Rethmeier, Michael T1 - Influence of Ti and B additions on grain size and weldability of aluminium alloy 6082 N2 - Grain refinement is an important possibility to enhance the weldability of aluminium weld metal that is usually defined by its susceptibility to solidification cracking. In this study, grain refinement was achieved through the addition of commercial grain refiner containing titanium and boron to the GTA weld metal of aluminium alloy 6082. The weld metal mean grain size could be reduced significantly from about 70 µm to a saturated size of 21 µm with a change in grain shape from columnar to equiaxed. The grain refinement prevented the formation of centreline solidification cracking that was present only in welds with unrefined grain structure. A variation of torch speed led to a strong change of solidification parameters such as cooling rate that was measured in the weld metal and the corresponding solidification rate and thermal gradient. The ratio thermal gradient/growth rate (G/R) decreased from 50 K s/mm² (high torch speed) to 10 K s/mm² (low torch speed). However, the variation of torch speed did not change the tendency for solidification cracking. The microstructure of unrefined and completely refined weld metal was compared. The observed change in size and distribution of the interdendritic phases was related to the change in susceptibility to solidification cracking. KW - Aluminium KW - WIG-Schweißen KW - Kornfeinung KW - Schweißeignung KW - Heißrisse KW - Aluminium alloy KW - Solidification cracking KW - Weldability KW - GTA welding PY - 2012 SN - 0043-2288 SN - 1878-6669 VL - 56 IS - 09/10 SP - 95 EP - 104 PB - Springer CY - Oxford AN - OPUS4-26992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kannengießer, Thomas A1 - Cross, Carl Edward A1 - Böllinghaus, Thomas ED - Karl-Heinrich Grote, ED - Erik K. Antonsson, T1 - Modern Joining Technology - Weld Simulation PY - 2009 SN - 978-3-540-49131-6 IS - Part B / 7.4.8 SP - 706 EP - 723 PB - Springer AN - OPUS4-19047 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Winzer, Nicholas A1 - Xu, Ping A1 - Bender, S. A1 - Gross, Thomas A1 - Unger, Wolfgang A1 - Cross, Carl Edward T1 - Stress corrosion cracking of gas-tungsten arc welds in continuous-cast AZ31 Mg alloy sheet N2 - AZ31 Mg alloy sheet was welded using a gas-tungsten arc (GTA) process over inserts containing 2.3-9.3 wt.% Al. The welded specimens were susceptible to SCC in distilled water, with susceptibility increasing with decreasing weld metal Al (or β particle) concentration. Primary stress corrosion cracks initiated at the weld metal-HAZ interface by stress-assisted localised dissolution and propagated through the weld and base metals by transgranular and intergranular H-assisted fracture (TG-HAF and IG-HAF) respectively. The IG fracture mode may be intrinsic to the texture imparted upon the base metal by rolling. The increase in SCC susceptibility with decreasing weld metal Al concentration is contrary to the purported roles of β particles in promoting localised corrosion and as crack nucleation sites, but corresponds with increases in weld - base metal galvanic current density and weld metal localised corrosion susceptibility. KW - C. Stress corrosion KW - C. Hydrogen embrittlement KW - A. Magnesium KW - C. Welding PY - 2009 DO - https://doi.org/10.1016/j.corsci.2009.05.037 SN - 0010-938X VL - 51 IS - 9 SP - 1950 EP - 1963 PB - Elsevier CY - Orlando, Fla. AN - OPUS4-20049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Babu, N. K. A1 - Cross, Carl Edward ED - Kainer, K.U. T1 - Influence of variable polarity pulsed current technique on grain refinement of AZ31 weldments T2 - Magnesium - 8th International conference on magnesium alloys and their applications CY - Weimar, Germany DA - 2009-10-26 KW - Variable polarity KW - Puulsed current welding KW - Magnesium KW - Grain refinement PY - 2009 SN - 978-3-527-32732-4 SP - 996 EP - 1003 PB - Wiley-VCH AN - OPUS4-20587 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -