The influence of microstructural deformations and defects on mechanical properties in cast aluminium components by using Digital Image Correlation Techniques (DICT)

• Main Author: Armanjo, Jahanmehr
• Format: Others
• Language: English
• Published: Högskolan i Jönköping, Tekniska Högskolan 2015
• Subjects: Al-Si cast alloys; AlSi7Mg0.3; strontium modification; heat treatment; SDAS (Secondary Dendrite Arm Space); Aramis; digital image correlation technique (DICT); mechanical properties (ultimate tensile strength; offset yield strength and elongation); plaster mould processes
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-28022

Digital image correlation techniques (DICT), a non-contact deformation measuring technique based on gray value digital images, have become increasingly used over the last years. By using the DIC technique during a tensile test, the deformation behavior of different engineering material under an applied load can be determined and analyzed. Digital images, acquired from a tensile test, can be correlated by using DICT software and from that the local or global mechanical properties can be calculated. The local or global mechanical properties determination of a flat test specimens are based on the displacements or changes in a previous stochastic sprayed or natural pattern. The used material for this purpose is cast silicon (Si) based aluminium (Al) component, designated as AlSi7Mg0.3 (Anticorodal-78 dv). The hypoeutectic Al- Si alloy is widely applicable for engine constructions, vehicle and aerospace constructions, shipbuilding, electrical engineering and constructions for food industry. There are many microstructural parameters in a binary system Al- Si alloys, which the mechanical properties can be depended on, for instance phase distribution, Secondary Dendrite Arm Spacing (SDAS), morphology of Si particles (Roundness) and microscopic defects or pores. All these parameters can contribute to enhance the proper mechanical performance (e.g. Strength and ductility) in the Al-Si cast components.