Karakteristik balistik komposit pelat tebal Al-9Zn- 6Mg -3Si berpenguat 5 vol,% ZrO2 dengan penambahan paduan mikro berupa Sr. Ti dan Cr hasil squeeze casting = Ballistic characteristics of Al-9Zn-6Mg-3Si composite thick plate reinforced by 5 vol.% of ZrO2 with microalloying of Sr. Ti and Cr fabricated by squeeze casting