PENGARUH VARIASI KUNINGAN TERHADAP POROSITAS DAN UJI IMPAK PADA HASIL PENGECORAN LIMBAH PISTON 2 TAK

Aluminum is one of the very light materials that has a high demand due to its properties such as strength, heavy density, durability, light weight, resistant to corrosion, easy to form, recyclable and very good as electrical conductivity. The problem that often occurs is the fatal damage caused by iron footstep, therefore this research was conducted to obtain alternative materials that utilize piston waste by combining brass because the addition of brass in a certain amount will add strength and tenacity and resistance to corrosion. The addition of brass variation used is 32%,33.5%,35%,36.5%. To find out the defects in casting that occur due to gas - hydrogen gas trapped in the mold therefore in the porosity testing, other testing is a useful impact testing to know the toughness of aluminum and brass alloys. The results of the study for impact testing, experienced a decrease in the price of impact directly proportional to the number of additions of brass variations in specimens. The impact price decreased quite drastically in the addition of brass variation 32% by 0.343 Joule⁄mm^2 ,, due to the occurrence of a fairly high porosity in the variation of brass addition of 32% by 7.51%. The occurrence of high porosity will affect the toughness of the specimen