Abstract
Ti-15V-3Cr-3Sn-3Al alloy sheets 1.6 to 7 mm thick were produced from a 100 kg ingot to study characteristics of manufacturing workability and heat treatability of the alloy.
It was proved that the alloy had higher hot working deformation resistance than Ti-6Al-4V alloy, the most widely used titanium alloy, but was superior in cold rollability and bending workability to Ti-6Al-4V. As the alloy was prone to pick up hydrogen during manufacturing processes, the problem of hydrogen contaminant must be fully considered in the processing.
β phase was completely retained throughout the thickness in the plate as thick as 14mm even by air cooling after solution heating.
The growth rate of β grain was comparatively low in the temperature range of 750 to 900°C tested. After solution treatment and aging, the coarser the β grain was, the lower the ductility became. When aging temperature was lower, precipitated, α phase was finer and strength became higher.
Tensile strength as high as 150 kg/mm2 could be attained by a suitable condition of cold rolling and subsequent aging.
