I have this 1946 silver dime with only the face side but I am not sure if someone altered it or not. Can anyone help out?
Yes it has been altered. The Reverse side has like a circle pattern. That is from a grinder. The Reverse is missing the raised rim. A blank planchet has an upraised rims on both sides not just one. And lastly, you can't have a perfect Obverse image without the Reverse being struck. you need a certain amount of striking pressure to create the image. I don't know the exact weight of a silver dime but if you weighed yours and compared it to a normal one, it would weigh less due to the missing metal.
I would guess it was turned on a lathe to have such concertric circles on it. It also must weigh less having metal removed.
Welcome to CT! This site sees quite a few coins like yours, the product of busy little hands, I suppose.