Pengaruh Bentuk Penampang Runner Terhadap Cacat Porositas Dan Nilai Kekerasan Produk Cor Aluminium Cetakan Pasir

Abstract

Abstract : This experiment is aimed to determine the influence of cross-sectional shapes of runner on porosity defect and hardness number of aluminium alloy castings product by using sand molds. The raw material of aluminium alloy in this experiment is derived from waste of truck pistons. Variations of crosssectional shapes of runner are: circular, rectangular, and triangular. The porosity testing is conducted by comparing the true density to the apparent density. The true density testing uses ASTM E-252 standard. The hardness number testing is conducted by using Brinell hardness testing machine with 10 mm of indenter’s diameter and 500 kgf of test force. The result showed that runner with circular cross-sectional shape has the lower average porosity percentage and higher hardness number than runner with rectangular and triangular cross-sectional shapes.

Keywords : Runner, Porosity, Hardness, Aluminium alloy