Are pewter burial urns resistant to corrosion?

Hi, my dad passed away many years ago, and my mother got him a cremation urn made out of silver, and, unfortunately, it has started eroding. My mother has passed as well, and I would like to place her next to my dad in the columbarium. However, I don't want to go the same route and get a silver burial urn that can rust eventually. Will pewter be a longer-lasting material, even when exposed to weather elements?