What alloy/metal should I use on my armor plating?

I am constructing a light weight metallic suit that will be flame resistant, bullet poof and obviously slash proof. I am having a problem with seperation of the plates and the fact that after being shot several times the plates begin to fracture. I am using 98.5% titanium alloy plating that is about 2.5" thick. Should I try a different alloy or metal? and what can I do about seperation of the plates, without gaps there is no flexibility.