Characterization of Ti-6 Per Cent Al-4 Per Cent Vand VasoMax C-350

摘要

The (alpha)-(beta) Ti-6% Al-4% V (Ti64) alloy can be heat treated to meet the specified requirements of the applications. The as-received material from SLAC was given a solution heat treatment (SHT) to have a good strength and ductility combination. The SHT was done at 200 degrees C below the Beta transus of 990 degrees C for 15 min and air-cooled to 20 degrees C. The designed microstructure consists of (beta) phase precipitates within the (alpha) phase matrix. The characterization of the as-received Ti64 alloy sheet microstructure reveals equiaxed, 10 (micro)m-sized grains on the flat surface and finer, 8 (micro)m-sized grains in the through thickness. Figures 1 and 2 show the microstructure of the alloy. The typical Ti64 microstructure is lamellar structure, consisting of alternating (alpha) and (beta) phases. In order for the alloy to have the micron sized, equiaxed grains, it had to undergo extensive wrought processing. The Vicker's microhardness numbers (VHN) showed that the slightly larger grained flat surface had a higher averaged value than the through thickness; 33 kg/mm(sup 2) vs. 30 kg/mm(sup 2). The residual effect of wrought processing is still present even after the SHT to cause the small difference in the hardness values.