1969 Volume 38 Issue 1 Pages 79-85
A study was made of the effects of filler metals on the weldability of AI-Zn-Mg alloys.
Aging characteristics, mechanical properties, stress-corrosion cracking susceptibility of welds and weld cracking susceptibility were examined by means of Vickers-hardness, tensile, bending, Charpy impact, stresscorrosion cracking, weld cracking and other tests.
The results obtained are summarized as follows.
(1) Tensile strength of welds made with Al-Mg-Zn filler metal was almost equal to that of Al-Zn-Mg filler metal and that of Al-Mg filler metal showed the lowest value, while the age hardening of welds increased in the following order; Al-Mg filler<Al-Mg-Zn filler<Al-Zn-Mg filler.
(2) However, bending and Charpy impact properties of welds made with Al-Mg filler metal were most excellent, and those of Al-Zn-Mg filler metal were inferior to those of Al-Mg and Al-Mg-Zn filler metals.
(3) No appreciable difference in stress-corrosion cracking susceptibility and fatigue properties was observed in AI-Zn-Mg, Al-Mg-Zn and Al-Mg filler metals.
(4) Weld cracking susceptibility increased in the following order; Al-Mg filler<AI-Mg-Zn filler<Al-Zn-Mgfiller. However, weld cracking susceptibility of Al-Mg-Zn filler metal containing a small amount of zirconium was almost equal to that of Al-Mg filler metal.