Yes.

It's in the very title of one chapter of Thomas Malory's Le Morte d'Arthur:

CHAPTER XXV. How Arthur by the mean of Merlin gat Excalibur his sword of the Lady of the Lake.

Most modern accountings of Arthur that are reasonably faithful to the story are based on Malory. For his part, Malory is condensing and editing the central Arthurian tradition of the previous centuries, which scholars call the Vulgate and Post-Vulgate Cycles. They represent the compilation of the "through-plot" of King Arthur, from the Holy Grail on up.

So yes, in Arthuriana, Excalibur is a sword.