Studi pengaruh penambahan penguat zro2 terhadap karakteristik komposit al-13, 1zn-6, 1mg-6, 7si-1, 4cu hasil squeeze casting untuk aplikasi balistik = The effect of zro2 reinforcement addition to the characteristics of al-13, 1zn-6, 1mg-6, 7si-1, 4cu composite with squeeze casting process for ballistic application