Are titanium alloy screws easy to break？

First, to explain a common misunderstanding of the "strength of titanium alloy",  titanium alloy is not a high strength material.

Titanium alloy screws have high specific strength. The so-called "specific intensity" is "the ratio of intensity to density". Usually titanium alloy screws buyers almost all are because of the characteristics of titanium alloy "low density, high strength", and  commomly used in the place which has the requirements of the combination of strength and weight. For example, the structural parts of aircraft, tuning car, motorcycle etc.

The titanium alloy is about 50-60 percent denser than 45 steel, but it is about as strong as 45 steel (titanium is slightly higher).

In other words, titanium screws are as strong as steel screws, but titanium screws are lighter in weight.