【将来】：时间词，现在以后的时间（区别于‘过去、现在’） 【未来】：1.没有到来;不来。 2.谓尚未发生。 3.佛教语。指来生，来世。 4.将来。 5.指将来的光景。 6.即将到来

you can treat 未来 as 未知的将来，which means unknown 将来

In my opinion,there are subtle difference....未来means a future beyond your horizon.....将来means a future under your control and imagination......未来sometimes refers to behaviours more risky,challengable,unknown and ambiguious....while 将来 indicates a highly possible and settled future situation......You can say 未来Robots will dominate earth...while 将来I will go to unversity.......将来is more similar to 以后.....

There is no difference in meaning between the two, though you are likely to find either used in certain fixed expressions where the other can’t be used.