Hi!
No, we don't expect Earth to ever turn into a black hole. Sometimes people ask if we expect our star, the sun, to turn into a black hole, but we don't think that will happen either.
Astronomers think that only very large stars, much larger than our sun, can become black holes. Our sun (and the earth) are just not big enough for this to happen.
you can read more about black holes here:
http://starchild.gsfc.nasa.gov/docs/StarChild/universe_level1/black_holes.htmlcheers,
Terry