Titanium is stable in air at room temperature; Because titanium has excellent properties such as low density, high strength, density only half of steel, strength similar to steel, high and low temperature resistance, corrosion resistance, etc., titanium alloys have higher strength than steel. Titanium is known as the "space metal" and can maintain high strength and mechanical function within a wide temperature range of -253 ℃ to 500 ℃. Titanium is also known as a "biometallic metal" by people. At the site of bone damage, titanium splints and titanium bone nails are used to fix it. After a few months, the bone will grow on the titanium splint and the threads of the titanium bone nails, and new muscles will wrap around the titanium splint. This type of "titanium bone" is like a real bone, and can even be replaced by titanium artificial bones to treat fractures.