Análise de porosidade: estudo de caso sobre uma tampa de cabeçote

Abstract

Overdue to the recurrent use of aluminum in foundry and automotive components, an analysis of its defects is necessary. One of the most common defects is porosity. Whether from trapped gas or shrinkage, porosity is a problem that affects part functionality. The objective of this work is through the XRay, Metallography and Spectrometry tests to reach the cause of the problem and thus propose possible solutions. According to the analysis, it was possible to see that there were both types of porosity in the samples, by contraction and by gases, which normally occurs in the last region to solidify, which is consistent with the analyzed sample. To reduce the defect of gas trapped in the part, the best way is to ensure that the gas outlets of the mold are well designed and working properly. These outlets must be positioned in the last areas of the mold to be filled. As shrinkage porosity is due to shrinkage resulting from volumetric variation during solidification, one way to solve this problem would be to control the speeds at which the part is injected.