Pengaruh Ukuran Riser Terhadap Cacat Penyusutan Dan Cacat Porositas Produk Cor Aluminium Cetakan Pasir

Abstract

Abstract : This experiment is aimed to determine the influence of riser size on shrinkage and porosity defect of aluminium castings by using sand molds. The raw material of aluminium alloy in this experiment is derived from waste of motorcycle piston. Bottle shape riser is used with the size of neckis 25 mm ofdiameters and 5 mm of height. Variations of riser size are: 30 mm of diameters with 100 mm of height, 40 mm of diameters with 56 mm of height, and 50 mm of diameters with 36 mm of height. The shrinkage testing is conducted by comparing the castings volume to the molds volume. The observation of shrinkage cavity is done by cleaving the castings into two pieces. The porosity is tested by comparing the true density to the apparent density. The true density testing uses ASTM E-252 standard.The result of this experiment are is to produce castings which low shrinkage and porosity defect is used riser which large of diameters and height size.

Keywords : Riser, Shrinkage, Porosity, Aluminium alloy