Iron is a common ore. Due to there being much more of it and relativity easy to us. This means it costs less to produce and is readily available. However,titanium is more of a 'precious' metal,as titanium is neither in plenty or easy to produce, it costs more. titanium is rarer and more difficult to extract. But,iron can be smelted in large quantities in a blast furnace.
The reactivity of titanium is much higher than iron. That means more energy is required to remove the elements Ti is bonded to. And, since titanium is very reactive, it requires more protection to prevent it from re-reacting during processing.Titanium is a critical materials for a wide range of aerospace applications where very high strength and low weight is required and temperatures are too high to use Al alloys. Ti is also widely used as a hard coating on metal cutting tools.
