Dissimilar Laser Welding/Brazing of 5754 Aluminum Alloy to DP 980 Steel: Mechanical Properties and Interfacial Microstructure

Abstract

A diode laser welding/brazing technique was used for lap joining of 5754 aluminum alloy to DP 980 steel with Al-Si filler metal. The correlation between joint interfacial microstructure, wettability of filler metal, and mechanical properties was systematically investigated. At low laser power (1.4 kW), a layer of intermetallic compounds, composed of h-Fe(Al,Si) 3 and s 5 -Al 7.2 Fe 1.8 Si, was observed at the interface between fusion zone and steel. Because of the poor wettability of filler metal on the steel substrate, the joint strength was very low and the joint failed at the FZ/steel interface. When medium laser power (2.0 kW) was applied, the wettability of filler metal was enhanced, which improved the joint strength and led to FZ failure. With further increase of laser power to 2.6 kW, apart from h and s 5 , a new hard and brittle gFe 2 (Al,Si) 5 IMC with microcracks was generated at the FZ/steel interface. The formation of g significantly degraded the joint strength. The failure mode changed back to interfacial failure.

Laser and Gas Metal Arc Based Dissimilar Joining of Automotive Aluminium Alloys and Steel Sheets - A Review

“…The authors found maximum joint strength of 180 N mm -1 with phase layer thickness around 2 ~ 3 ㎛. Yang et al 24) used heat input of around 70 ~ 168 J mm -1 to join 2 mm thick AA5754 alloy and 1 mm thick galvanized DP980 steel sheets by diode laser beam using AA4047 filler wire. Fig.…”

“…At a medium heat input of 120 J mm -1 , the joint strength was Heat input (J mm -1) Phase layer thickness (㎛) Heat input(J mm -1 ) Joint strength (N mm -1 ) Fig. 2 Influence of heat input on joint strength in laser beam joining of AA5754 alloy and galvanized DP980 steel sheets 24) 대한용접․접합학회지 제36권 제5호, 2018년 10월…”

Consideración sobre la soldadura de transferencia de metal frio de AA5754 al acero galvanizado a partir de aspectos mecánicos y microestructurales

“…Chemical compositions of some Al/Fe and Al/Fe/Si IMCs are listed in Table 6 based on the (Song et al, 2009) literature findings. It was noticed that the chemical composition of 5G-1 was found to be similar to Al 7.2 Fe 1.8 Si phase as mentioned in (Song et al, 2009;Yang et al, 2015). According to Al-Fe binary phase diagram, Fe 2 Al 5 compound contains 53-57 wt.% aluminum (Kattner and Burton, 1992).…”

“…Figner et al (2009) examined the friction stir spot welding of aluminum AA5754 and galvanized steel HX 340LAD. Yang et al (2015) studied lap joining of AA5754 to DP 980 steel by diode laser welding and investigated the correlation between interfacial microstructure and mechanical properties. They obtained a hard and a brittle Fe 2 (Al,Si) 5 (η phase) with micro cracks between steel and aluminum at high laser power.…”

Diode Laser Welding/Brazing of Aluminum Alloy to Steel Using a Nickel Coating

“…Their chemical compositions and mechanical properties are given in Tables 1 and 2 Base materials were machined as rectangular strips of 50 × 60 mm 2 . The aluminum alloy sheets went through a very strict two-step cleaning process, which was shown in our previous study [19]. The steel sheets were cleaned in acetone, and then ground to 1000 grit using SiC abrasive paper and again ultrasonically cleaned in acetone.…”