Spawanie stopów magnezu wiązką laser CO2

Zwiększenie wymagań dotyczących bezpieczeństwa środków transportu i komfortu podróżowania przy stosowaniu części wykonanych z tradycyjnych materiałów (stali lub stopów aluminium) powoduje znaczny wzrost zużycia paliwa i zanieczyszczenia środowiska.

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The objective of this paper is to present the experimental methods applied for developing of the technology of keyhole laser beam welding of magnesium alloys. With the disposal of CO2 laser of maximum power of 2,5 kW the workpieces of alloys of MgAlZn and MgLiMn groups have been buttwelded with helium used as a shielding gas. The beam focal characteristics were determined by means of beam analyzer and the focal position have been consequently chosen with regard to the metal surface. With the helium shielding the macrostructures of the fusion zones are characterized by nearly parallel boundaries (only metal vapour plasma appeared). The analysis of microstructures of the joints and the tensile strength tests (until fracture) have permitted to determine the conditions when the joints of the best strength and without porosity could be obtained. The mesurements of hardness distributiion and the elemental distribution in the weld cross-sections allowed to find the changes due to heating in the fusion zone. The results of comparative corrosion resistance tests on base metals and the welds are reported.