The Swiss legend raced into an early lead as he took the first set 6-1, and he was 4-1 up in the second before Chung called the trainer after suffering from blisters.
Federer beat Cilic in straight sets in the Wimbledon final a year ago, the Croatian reduced to tears as he also struggled with blisters, but the world number two is expecting a closer encounter at Melbourne Park.
Hyeon Chung wasn't on Twitter before he began his historic run at the Australian Open, becoming the first Korean player, male or female, to reach the semifinals of a Grand Slam.
India's Rohan Bopanna and Timea Babos of Hungary progressed to the mixed doubles final, defeating Brazilian Marcelo Demoliner and Spain's Maria Jose Martinez Sanchez 7-5 5-7 (10-6) on Margaret Court Arena.More news: Meet Australian Open Winner Caroline Wozniacki
'We saw it against Rafa, we saw it last night again against Edmund, he brings the power, he brings basically everything, ' he said after beating Chung.
Now Federer will take on Marin Cilic, the man he beat on Centre Court in July, for his sixth Australian Open.
"Not having a brutal semi-final, he'll have rest and we'll see a different Marin Cilic this time".
"Over the last few days, it was blister under blister under blister", said Duguid. Now it's redrawn. They tried injections to see if it numbed the pain. "A lot of players get callus and as they go, they shave them down, but because I played so many matches in a row, I didn't know to shave them down, so that's how they started". I can play, like, more comfortable on the court with the great players like Roger.
"I just have to play a good match", Federer said. Not under the circumstances I was hoping to or not planning with.More news: The Potentially Life-Saving Feature Added in iOS 11.3
"I'm playing much, much more aggressive", Cilic said. "I can't finish the match, so I can't play anymore", he said. To get to know the man behind the tennis player, I guess, even though I got to know him better through the Laver Cup and so forth'. I've played with blisters in the past a lot and it hurts a lot.
Federer, through to the final without dropping a set, was not complaining and was prepared to be ruthless, saying: 'I knew he was having issues with his feet going into it.
Federer is supremely confident he has it all in place to join Djokovic and Australian Roy Emerson with the most Australian titles.
Considered one of his biggest strengths, Cilic needs to make a high percentage of first serves to have any chance.
Chung's ranking is set to rise into the top 30 next week, just a couple spots below another of his idols, Kei Nishikori of Japan, a former U.S. Open finalist. "I don't think about I'm not going to play today".More news: Did Trump Just Apologize For Anti-Muslim Tweet?
"I'm happy to be able to make the semis in a grand slam".