The main purpose of "grain refinement" is actually "pore refinement". The titanium boride particles ensure that many small pores form instead large pores.

Grain refiner will improve the properties only. No much side effect will be due to adding of grain refiner.

Grain refiners inhibit grain coarsening while grain refinement is a desirable attribute in metals based on Hall Petch relationship. Side effect of grain refiner may ensue if there is an excessive addition, which may lead to uneven structure or agglomeration of hard refiners.

Olatunji Oladimeji Ojo

Thanks Mr. Olat, can you please share with me some paper about grain refiner addition