DEVELOPMENT OF A STABLE-BETA TITANIUM ALLOY.
Quarterly rept. no. 6, 1 Oct-31 Dec 63
TITANIUM METALS CORP OF AMERICA NEW YORK
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An attempt to induce compound precipitation hardening in Ti-17V-10Cr-3Al, Ti-8Mo-8V-7.5Fe-3Al, Ti-8Mo-8V7.5Fe-3Al-1Co and Ti-15Mo-5Fe-3Al alloys by cold reduction and subsequent aging resulted in hardening by alpha precipitation instead. Similar work on Ti-17V-8Cr-3Al-3Ni indicated that this alpha hardening was induced by either hot or cold rolling and suppressed by solution treatment. Solution treating, quenching and aging Ti-17V-10Cr-3Al, containing 0.5 and 1 Si, at 1250F resulted in rapid hardness increases of up to 100 Vickers points without any clear accompanying microstructural change slow cooling suppressed this aging response. Aging responses were determined for the metastable alloys Ti-17V1.5 to 4Fe-3Al and Ti-8Mo-8V-1 to 3 Fe-3Al, over a range of times and temperatures. A statistical correlation between Vickers hardness and ultimate tensile strength on stable-beta alloys indicated that 25 Vickers points corresponded to about 10,000 psi. Two metastable and two stable-beta alloys were selected for further evaluation as larger ingots metastable Ti-17V-4Fe-3Al and Ti-8Mo-8V2Fe-3Al, and stable-beta Ti-17V-10Mn-3Al and Ti-8Mo-8V6Fe-3Al, respectively. Author