No, they can't be interchanged all the time. There's a couple of differences at least. Difference #1: For an event that happened in the near past that is a once-only or unique event, you must use 'recently' and not 'lately'. "My father died recently" - You cannot say "My father died lately" "My sister went on a holiday recently" - You cannot say "My sister went on a holiday lately" Difference #2: When something occurs habitually and it is happening NOW, we usually (but not always) say "lately'. "He's been sick a lot lately" - He's been sick several times in the past and you are implying he is STILL a bit sick" "He's been sick a lot recently" - He's been sick several times in the past, but I am NOT implying he's still sick today.

Greg has answered your question very well you do not need any other answers.