TITLE:
Experimental Studies of Self Healing Behaviour of Under-Aged Al-Mg-Si Alloys and 60Sn-40Pb Alloy Reinforced Aluminium Metal-Metal Composites
AUTHORS:
Kenneth Kanayo Alaneme, Oluwafemi Isaac Omosule
KEYWORDS:
Aluminium Alloys, Secondary Precipitation, Self Healing Metals, Healing Efficiency, Mechanical Damage, Biomimetics, Low Melting Point Reinforcement
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.3 No.1,
December
26,
2014
ABSTRACT: Experimental studies to demonstrate self healing potentials of Al-Mg-Si alloy were undertaken in this research work. Self healing exploring secondary precipitation in the Al-Mg-Si alloy and use of low melting metallic alloy reinforcement (60Sn-40Pb alloy) were used as basis for the investigation. For the precipitation study, the Al-Mg-Si alloy was under-aged at temperature of 160oC for 10 minutes and then subjected to second step ageing treatment at four different temperatures within the range of 25oC and 70oC. In the 60Sn-40Pb alloy reinforced Al-Mg-Si alloy study, the samples were prepared in pre-cracked state and then subjected to healing heat-treatment at 250oC. For all cases tensile test and healing efficiency was used to analyze the results generated. It was observed that a second step thermal ageing at 50oC resulted in peak improvement in tensile strength, yield strength, toughness and percent elongation while ageing above this temperature lead to a drop in the tensile properties in comparison to that of the sample not subjected to a second ageing treatment. Also the use of 60Sn-40Pb alloy as reinforcement in the Al-Mg-Si alloy resulted in a healing efficiency of 91% after pre-cracking and heat-treatment. The satisfactory bonding between the 60Sn-40Pb alloy and the Al-Mg-Si alloy matrix contributed to the high healing efficiency observed.