WHBM
The fan blades on the GE90 series are carbon composite construction, with a TI leading edge (GEnx uses the same basic fan blade design). The GE90 blades have proved to be amazingly durable - I can't recall a single fan blade release or failure on a GE90. I don't know if it's still true, but back in the early 2000's GE had a sign in their training center stating that a GE90 fan blade had never needed to be scrapped due to in-service damage.
Memory says the Trent engine uses a TI skin over a TI honeycomb matrix material - and I believe they use the same construction on all their wide-cord fan blades. Rolls has had issues with fan flutter with their fan blades - the RB211-524G/H, Trent 800 (777), and Trent 1000 (787) have all had to implement fan 'keep out zones' which prevent engine operation in a defined RPM range without forward airspeed. I recall a Trent 800 FBO event back around year 2000, although IIRC it wasn't the blade that failed - the blade 'dovetail' root failed due to improper lubrication.