Laser pressure welding of Al alloy and low C steel

Abstract

This study was performed to obtain fundamental knowledge concerning the development of laser pressure welding technology for the joining of dissimilar metals. Laser pressure welding of Al alloy A6061 and low C steel SPCC sheets was carried out to investigate the effects of the roller pressure, laser beam scanning speed and irradiation position on the tensile shear and peel strength of welded joints. The interfaces of the joints were observed and analysed by SEM and EDX, and the formation phases on the peeled surfaces were identified with XRD. It was revealed that prevention and suppression of oxidation during welding was extremely important to the production of a sound joint with good mechanical properties. The highest tensile strength and the highest peel strength of joints were obtained at a laser power of 1 . 8 kW, laser scanning speed of 30 Hz, laser irradiation position at the centreline, roller pressure of more than 245 MPa and welding speed of 0 . 5 m min -1 in an Ar atmosphere. The fracture occurred not in the welded zone but in the A6061 base alloy specimen.

Joining Al 5052 alloy to aluminized steel sheet using cold metal transfer process

“…Autogenous ''braze welding'' [4,5], laser pressure welding [6][7][8][9] in which pressure was simultaneously applied with laser irradiation, and filler-metal-added braze welding [10][11][12][13][14][15][16] have been considered. In these studies, only the Al alloy was melted, while the steel remained unmelted.…”

Effectiveness of Pilates exercise in treating people with chronic low back pain: a systematic review of systematic reviews

“…There was also inconsistency across reviews regarding the description of comparison physiotherapy treatment within the Obrien et al 2006 [32] study. Pereira et al (2012) [8] defined the type of physiotherapy as lumbar stabilisation exercise, while Lim et al (2006) [7] reported that the physiotherapy treatment included other modalities as well.…”

“…Timing of evaluation was dependent on the duration of the Pilates treatment and the length of follow up. The shortest follow up was at 6 weeks [28,31,32] and longest follow up assessment was at 12 months following the completion of Pilates treatment [24,25,30]. …”

“…There were ten different primary studies identified across the five systematic reviews [24-32,35] (Table 5). La Touche et al (2008) [6] and Posadzki et al (2011) [9] included only studies published in full, as opposed to Aladro-Gonzalvo et al (2012) [10], Lim et al (2011) [7], and Pereira et al (2012) [8] who included studies that were unpublished, or part-published [24,28,29,32,35].…”

Friction Stir Brazing: a Novel Process for Fabricating Al/Steel Layered Composite and for Dissimilar Joining of Al to Steel

“…[2,3] As a unique kind of energy source, laser beam provides some attractive advantages, including high power density, small heating area, rapid heating/cooling rate, and low heat input, which are beneficial in inhibiting the formation of IMCs. In recent years, several laser-assisted joining processes have received more attention; these include laser-assisted roll bonding, [4] laser pressure welding, [5] laser-induced reactive wetting without filler metal (only irradiating Al sheet to melt it), [6] laser brazing (only irradiating filler metal wire or steel sheet to melt filler metal by direct heating or heat conduction through the hot steel sheet), [7][8][9] and laser braze welding (irradiating both filler metal wire and Al sheet to melt and mix them). [10,11] For laser-assisted joining processes, shielding gas (argon) [6][7][8][9][10][11] or brazing flux (e.g., fluor-base anticorrosive brazing flux [6][7][8]11] ) is necessary, although satisfactory strength can be obtained by optimizing filler metal (e.g., using Zn filler metal instead of the Al base one [9,10] ) and process parameters.…”