Titanium alloys are used in aerospace engineering to make very strong and light parts of aeroplanes. These alloys can replace steel because they are almost as strong as steel but much less heavy, and are much stronger than aluminium alloys but only a little heavier. This means that the titanium parts can be thinner and lighter, but still withstand the same forces. It does not corrode in many conditions, not even in sea water and chlorine. However, it can burn at high temperatures, and like many metal powders, titanium dust is extremely flammable. 