The mechanic replaced both rotors and pads.
I probably didn't explain the axle replacement well. Only the right axle assembly was replaced, and it was done at the same time as both brakes (rotors and pads), probably because the bearing or the joint had started to be noisy (I have forgotten the reason, but I trust the mechanic since I have along term relationship, and he often does stuff at no charge).
The noise was periodic, like: clunk, clunk, clunk at the same speed as the wheel. It didn't sound like a caliper sliding on a surface. When it happened I could even hear it in the parking lot going 1 mph, standing outside the car and my wife driving in a circle. At that speed it was like:
clunk, ... 1 second, clunk, ... 1 second.
That is the clunk would last about 1/10 second, then there would be an interval of 1 second, and then again, clunk. So it was definitely in a particular position and it didn't seem caused by something sliding.