Structure and mechanical properties of explosive welded Mg / Al bimetal Institute of Materials Research SAV Košice, Slovak republic Dušan Balga et al. | 2014 |

2 Outline 1.our material 2.metallography 3.optical profilometry 4.SEM / EDX 5.microhardness 6.hard X-ray micro-diffraction experiment –phase analysis –computation of lattice parameters of Al and Mg 7.conclusion

3 Mg / Al bimetal Cooperation and word of thanks: –prof. Ing. Eva Mazancová, CSc. –Ing. Dmytro Ostroushko VŠB-Technical University of Ostrava, Czech republic manufacturer: EXPLOMET, Poland Mg: -lightest among metallic materials -density is about 2/3 of that of aluminium -recycled without any degradation in physical properties Al: -corrosion resistance -high strength to weight ratio -good formability Combination of Mg and Al would be promising structural material (aerospace, automobile industry)

4 Metallography average thickness of the interface 45 microns

5 Optical profilometry the difference is approximately 8 microns (Al higher)

6 Optical profilometry

7 SEM/EDX ElementWeight%Atomic% O K Al K Cu K Al ElementWeight%Atomic% O K Mg K Si K weld, tilt of the specimen 70° Mg Al

SEM/EDX Element POINT: Mg [wt. %] Al [wt. %] Si [wt. %] Fe [wt. %] Cu [wt. %] O [wt.%] 1627,30,434,132,2- 23,781,7-1,610,52,5 385,411,70,2--2,7 488,9-0,7-1,29,2 595,4----4,6 Mg Al weld, tilt of the specimen 70° Al weld, tilt of the specimen 0°

Micro - hardness 9 step: 120 microns micro - hardness of the joined materials measured far from their interface is similar for both materials in the region of interface the hardness drops down by 40% to about 50 HV0.1

10 Hard X-ray micro-diffraction experiment beam size: 2,2 x 34  m E= 99 keV 251 2D XRD patterns

11

12 weld Al Mg

13 Phase analysis

14 Al

15 Mg

16 Conclusion –the results of metallographic and microchemical analysis showed that a wavy Al / Mg explosive welded interface is molten in a very thin (45  m wide) region –in the welded bond, there is substantial chemical inhomogeneity –hardness in the middle of the Al / Mg interface region drops down by 40% from ~80HV0.1 to ~ 50 HV0.1 indicating some kind of thermal induced microstructure relaxation –at the interface no intermetallics were observed –we proved an existence of solid solution with gradually changed chemical composition from the centre of weld to the material

Acknowlegements Ing. Karel Saksl, DrSc. Institute of Materials Research SAV, Slovak republic prof. Ing. Eva Mazancová, CSc. Ing. Dmytro Ostroushko VŠB – Technical University of Ostrava, Czech republic the staffs at Beamline P07 – PETRA III, HASYLAB (DESY) – Germany for technical support during experiment Explomet Company Slovak Grant Agency for Science –Grant No. 2/0128/13 Ministry of Education, Youth and Sports of Czech Republic –project No. L01203 "Regional Materials Science and Technology Centre – Feasibility program“ –project MK No /2013/RRC “International research teams” 17

THANKS FOR YOUR ATTENTION Slovak Academy of Sciences Institute of Material Research Kosice, Slovakia