Is there anyway that I break a single part into different parts in creo parametric so that I could assemble these parts to make the whole again. Actually I want to break a single part into different components because this way they can easily be casted individually and later on assembled together. Thanks in advance.
You can suppress features that define the parts you'd like to remove, leaving only the one part you want to keep, then save that as a new file for the remaining part, and repeat for all parts.
Or, you can export the file into your chosen filetype, say a .stp file, and then reimport it and delete the components you don't need for that particular part using the Import Data Doctor tool (IDD).
But, I usually just make extruded cuts to eliminate features I don't want, then save as a new part, and repeat for each part.
You can save the assembly in any format (step, igs, parasolids, etc.)
While saving select option as surface. whole assembly will be saved as a single part.
In Catia there is body features. So you can split them into several parts. But in creo never heard. Creo is worst cad program.