What material is the Ti fastener going into? Most Ti fasteners are a 6AL-4V alloy (meaning they have a percentage of aluminum in them) Galvanic corrosion is not as much of a concern with Ti alloys and Aluminum parts as commercially pure TI and commercially pure AL but it can still happen. Over time the TI bolts could weaken and fail if not checked periodically. Periodic checking would also keep threads from bonding together over time. There are all sorts of studies out there about galvanic corrosion relating to CF, TI, Steel, and AL.