Complex sentence: Magnesium alloys can be spot-welded nearly as easily as aluminum, but scratch brushing or chemical cleaning is necessary before the weld is formed fusion welding is carried out most easily by processes using an inert shielding atmosphere of argon or helium gas.
Split into simpler sentences: Magnesium alloys can be spot-welded nearly as easily as aluminum, but scratch brushing or chemical cleaning is necessary before the weld is formed. Fusion welding is carried out most easily by processes using an inert shielding atmosphere of argon or helium gas.