Microstructure control and mechanical property correlation in Titanium alloy Ti-6Al-4V fasteners for space applications

摘要

High strength fasteners of Titanium alloy Ti-6Al-4V are widely used in both launch vehicle and satellite structures. Ti-6Al-4V fasteners having three different types of microstructures were analysed for mechanical properties to understand the role of two phase α+β or transformed β phase in the head region. Based on the microstructure-mechanical property correlations, it was concluded that the presence of transformed beta phase will not affect the strength properties, but will produce scatter in percentage elongation, percentage reduction in area and failure torque values. Therefore, it is recommended that the microstructure of aerospace titanium alloy Ti-6Al-4V fasteners should contain homogeneous two phase α+β throughout.