Be careful of the toxicity of an aluminum/beryllium alloy. Be sure to get a materials data sheet for that type of alloy. Different alloys have different levels of toxicity but I am guessing that one will require special precautions to cut or grind.

As an alternative take a look at aluminum matrix metals, M2 for example.

In general be real careful with exotic materials or materials not commonly used in manufacturing. In many cases there is a good reason they are not used.

I hate to keep saying this over and over but you only have to sit and wait for the medical people to go over the instrument reading trying to decide if you are going to die or not to be very respectful of the concept of toxic materials.