LPSO phase SEM/EBSD Technology: general issues Ti6Al4V/Al-1060 aluminum carbon steel cellular metal cloud of particles collision conditions collision welding composite structure confinement layer dissimilar materials dissimilar metals energy efficiency explosive compaction explosive welding flyer rebound flyer size flyer velocity gelatin high-energy-rate forming high-velocity impact welding impact angle impact velocity impact welding interface interlayer jet magnesium alloys