The need for aluminium alloys having a good toughness, high strength, adequate damage tolerance capability, good fatigue resistance and good corrosion resistance for use in applications in the industries of aerospace, automotive and even commercial products led to study of the properties and structure of the AlSi9Cu3 cast alloy. The most important metallurgical parameters affecting the Al-alloy’s resistance to fatigue are the amount and size of casting defects. Therefore was used quantitative analysis for determination of casting defects amount and size by optical microscopy on metallographic sections and an analysis of the size distribution by extreme value statistics. The software NIS Elements was used for quantitative analysis of casting defects and shows that porosity have a great influence on to the fatigue properties of AlSi9Cu3 cast alloy.

This work has been supported by The Scientific Grant Agency of the Ministry of Education of the Slovak Republic No 1/0533/15, No 044ŽU – 4/ 2017.

This publication is the result of the project implementation: The competence Centrum for industrial research and development in the field of light metals and composites ITMS: 26220220154 supported by the Operational Programme Research and development funded by the ERDF.