Resistance welding methods, assemblies, and vehicles

A resistance-welded metal assembly comprising:

• a first workpiece formed of a 7075 series aluminum alloy;
• a second workpiece formed of the 7075 series aluminum alloy;
• and
• a weld nugget that forms all or part of a weld joint between the first workpiece and the second workpiece;
• wherein the weld nugget has a composition that is a mixture of compositions of the first workpiece, the second workpiece, and an intermediate material;
• wherein the intermediate material is formed of a second alloy having a composition comprising:
• at least about 97.0 wt. % Al;
• equal to or less than 0.25 wt. % Zn;
• between about 0.45 and 0.7 wt. % Mg;
• between about 0.8 and 1.5 wt. % Si;
• and
• between about 0.01 and 0.11 wt. % Cu,
• wherein the first workpiece and the second workpiece each include a higher concentration by weight percent than the second alloy of at least one alloying element chosen from the group consisting of zinc, magnesium, and copper.

A vehicle comprising:

• a resistance-welded metal assembly comprising:
• a first workpiece formed of a 7075 series aluminum alloy;
• a second workpiece formed of the 7075 series aluminum alloy;
• and
• a weld nugget that forms all or part of a weld joint between the first workpiece and the second workpiece;
• wherein the weld nugget has a composition that is a mixture of compositions of the first workpiece, the second workpiece, and an intermediate material;
• wherein the intermediate material is formed of a second alloy having a composition comprising:
• at least about 97.0 wt. % aluminum;
• equal to or less than 0.25 wt. % zinc;
• between about 0.45 and 0.7 wt. % magnesium;
• between about 0.8 and 1.5 wt. % silicon;
• and
• between about 0.01 and 0.11 wt. % copper,
• wherein the first workpiece and the second workpiece each include a higher concentration by weight percent than the second alloy of at least one alloying element chosen from the group consisting of zinc, magnesium, and copper.