TiAlN coated tools have a coating that is partly aluminum oxide, that is the Al part of the name. Using these cutters for aluminum is not successful because the aluminum oxide coating tends to stick to aluminum not allow the chip to slide past. Not even flood coolant can overcome this stickiness and if you try using these cutters on aluminum at high rpms on a big machine you get a smoking, steaming blob of metal spinning round.
An open mind is a virtue...so long as all the common sense has not leaked out.