The influence of Strontium level on the microstructure formations and mechanical properties of Al-Si alloys
2013 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Student thesis
Abstract [en]
Abstract
The aim of this thesis is to investigate the influence of Strontium (Sr) addition on the microstructure formation, including porosity and the mechanical properties of commercial Aluminum alloy ENAC 46000. In addition, it is intended to obtain an optimum Sr level in order to achieve the desired mechanical properties.
Specimens were prepared with gradient solidification technique at different cooling rates in order to achieve samples with a variety of microstructural coarseness. Beside microstructural and mechanical properties studies, thermal analysis was employed to keep track of the time and temperature of phases during solidification.
The achieved results indicate that Sr affects the mechanical properties except the strength. The analysis of the result indicates that the optimum level of Sr is 150 ppm.
Porosity is a function of both Sr addition and cooling rate. Comparing the influence of cooling rate with Sr addition on the amount of porosity shows that the cooling rate can modify the ENAC 46000 alloy more than Sr addition.
Thermal analysis technique used to study effect of phase formation on modification. Influence of solidification rate and Sr level on time and temperature of α-Al (Τ_α) and Al-Si eutectic (Τ_N) nucleation was observed.
Place, publisher, year, edition, pages
2013. , p. 76
Keywords [en]
Aluminum alloy; Aluminum; microstructure; Strontium modification; cooling curve; solidification; mechanical properties; secondary dendrite arm spacing;
National Category
Metallurgy and Metallic Materials
Identifiers
URN: urn:nbn:se:hj:diva-21484OAI: oai:DiVA.org:hj-21484DiVA, id: diva2:629302
Subject / course
JTH, Product Development
Presentation
2013-05-10, 1408, Campus Gjuterigatan 5, Jonkoping, 01:36 (English)
Supervisors
Examiners
2013-06-192013-06-172013-06-19Bibliographically approved