Pengaruh Penampang Ingate Terhadap Cacat Porositas Dan Nilai Kekerasan Pada Proses Pengecoran Aluminium Menggunakan Cetakan Pasir

Abstract

Abstract : This research is aimed to determine the influence of cross-sectional shapes of ingate on porosity defect and hardness number in aluminum alloy castings processby using sand molds. The raw material of aluminum alloy in this experiment is derived from waste of motorcycle brake shoes. Variations of cross-sectional shapes of ingate are: circular, rectangular, and triangular. The porosity testing is conducted by comparing the theoretical density to the actual density. The theoretical density testing uses ASTM E 252-06 standard and the actual density testing uses archimides theory. The hardness number testing is conducted by using Rockwell hardness testing machine with 1/16 inch of ball indenter’s diameter and 100 kgf of test force. The result of circular cross-sectional has the lowest average porosity percentage and highest hardness number.Ingate with circular cross-sectional shape has average porosity percentage 1,93 % and it hardness number is 58,05 HRB.

Keywords : Ingate, Porosity, Hardness, Aluminum alloy