Hawkman as far as I'm aware, yes it DOES become stronger... but this has a downside. If you understand stress and support from a mechanical side of things it's a downside.

If someone has broken their arm exactly half way down and lets it rest and heal up fine then what you'll find is that the bone is thicker and harder around the area of the initial break. The downside to this is in the way that teh bone then absorbs impact shock, stress and tension. If blocking a kick, the bone will always bend somewhat, it might be only a fraction of an inch but it WILL give somewhat to alleviate the impact shock. The thicker part of the bone will no longer give in the way that it used to and what'll usually happen is that it focuses a lot more stress on a point just below the inital break point where the bone is the same thickness it's always been.

When the impact shock is absorbed onto high stress areas like this it can result in another break and it's usually more likely to happen than the initial break was.