Abstract
The objective of this study is to manufacture a near actual-size die-forged Ti-17 (Ti-5Al-2Sn-2Zr-4Cr-4Mo) disk in consideration of its jet engine applications, and to evaluate its mechanical properties, comparing with those of other high strength titanium alloys.
The major results obtained are as follows :
(1) High tensile strengths, ranging 122 to 126 kgf/mm2, were attained, and elongations were over 8 percent at widely sampled locations.
(2) Fracture toughness values were 160 and 210 kgf/mm2·√mm for radial and tangential cracking directions, respectively, which were proved excellent in comparison with those of other high strength titanium alloys.
(3) High cycle fatigue strengths and fatigue crack growth rate, espacially at high stress intensity range, had a great advantage over such a high strength alloy as Ti-6Al-2Sn-4Zr-6Mo. Strain controlled low cycle fatigue properties were equivalent to other widely available titanium alloys.
(4) Creep strengths studied at relatively lower temperatures than 500°C were equivalent or superior to Ti-6Al-2Sn-4Zr-2 Mo with high temperature applications.
