Not really, “as a weapon,” but it is possible to use a ridged scabbard somewhat creatively in combat. Mostly I’m thinking of using one as an improvised parrying tool. Though there are some other potential applications. For example: Blocking an incoming strike with the scabbard and then striking their swordarm with the blade.
Poking someone with the scabbard is technically possible, but there isn’t much point. Nothing prevents them from grabbing the scabbard in retaliation, and it’s not going to be doing any appreciable damage. But, if you really want your character to aggressively annoy someone, then it is one of many options.