Effects of silicon on characteristics of dynamic strain aging in a near-α titanium alloy

The effects of temperature and strain rate on the tensile properties of Timetal 834 near-alpha titanium alloy and alloy 834 without silicon were examined in the temperature range of 250 degrees C to 600 degrees C, employing strain rates in the range of 6.67 x 10(-6) s(-1) to 6.67 x 10(-3) s(-1). Manifestations of dynamic strain aging such as serrated flow, plateaus in the variations of 0.2% yield strength and ultimate tensile strength, peak in strain hardening exponent with temperature and negative strain rate sensitivity were observed in both the alloys. Serration maps in terms of strain rate versus temperature are presented for both the alloys. The activation energy for serrated flow was determined in both the alloys by employing various methodologies mentioned in the literature. Analysis of the results suggested that addition of Si leads to increased severity of dynamic strain aging.