Computationally-designed transformation-toughened near-alpha titanium alloy

Patent metadata

Field	Value
Publication number	US-10544496-B2
Application number	US-201816038527-A
Country	US
Kind code	B2
Filing date	Jul 18, 2018
Priority date	Aug 29, 2014
Publication date	Jan 28, 2020
Grant date	Jan 28, 2020

Abstract

A near-α transformation-induced plasticity (TRIP) titanium (Ti) alloy is designed by using a thermodynamic database and a mobility database of Ti alloys for α, β, and Ti 3 Al phase equilibria and diffusive processes; based on experimental data, creating a thermodynamic and kinetic database for β-to-α′/α″ martensitic transformations in the Ti alloys; creating a molar volume database for the β-to-α′/α″ martensitic transformations in the Ti alloys at room temperature; and obtaining an overall composite of the near-α TRIP Ti alloy by adjusting a reference overall composite of a reference near-α Ti alloy based on the created thermodynamic database, where the reference near-α Ti alloy is Ti-5Al-1Sn-1Zr-1V-0.8Mo-0.1Si-0.1Fe-0.1O by weight percentage (Ti-5111), and wherein the near-α TRIP Ti alloy is Ti-8Al-1V-1Sn-1Zr-0.6Mo-0.9Fe-0.1Si-0.1O by weight percentage.

First claim

What is claimed is:

1. A near-α transformation-induced plasticity (TRIP) titanium (Ti) alloy designed by a method comprising:
using a thermodynamic database and a mobility database of Ti alloys for α, β, and Ti 3 Al phase equilibria and diffusive processes;
based on experimental data, creating a thermodynamic and kinetic database for β-to-α′/α″ martensitic transformations in the Ti alloys;
creating a molar volume database for the β-to-α′/α″ martensitic transformations in the Ti alloys at room temperature; and
obtaining an overall composite of the near-α TRIP Ti alloy by adjusting a reference overall composite of a reference near-α Ti alloy based on the created thermodynamic database, wherein the reference near-α Ti alloy is Ti-5Al-1Sn-1Zr-1V-0.8Mo-0.1Si-0.1Fe-0.1O by weight percentage (Ti-5111), and wherein the near-α TRIP Ti alloy is Ti-8Al-1V-1Sn-1Zr-0.6Mo-0.9Fe-0.1Si-0.1O by weight percentage.

2. A near-α transformation-induced plasticity (TRIP) titanium (Ti) alloy, comprising:
Ti-8Al-1V-1Sn-1Zr-0.6Mo-0.9Fe-0.1Si-0.1O by weight percentage, being annealed at an annealing temperature.

3. The near-α TRIP Ti alloy of claim 2 , wherein the annealing temperature is about 865° C.

4. The near-α TRIP Ti alloy of claim 3 , being cooled at a cooling rate after annealing at the annealing temperature, wherein the cooling rate is greater than about 20° C./min to inhibit formation of grain-boundary α (GB-α) phase in the near-α TRIP Ti alloy.

5. The near-α TRIP Ti alloy of claim 3 , having a M S σ (ct) temperature of about room temperature, wherein the M S σ (ct) temperature is a M S σ temperature at a crack-tip (CT) stress state, and the M S σ temperature is a temperature at which transformation stress equals parent-phase slip stress.

6. The near-α TRIP Ti alloy of claim 2 , having a transformation dilatation of about +0.27%, and a β-phase fraction of about 19.5%.

Assignees

• Univ Northwestern

Inventors

• Yan Jiayi
• Olson Gregory B

Classifications

• C22F1/183 Primary

  of titanium or alloys based thereon · CPC title

• C22C14/00

  Alloys based on titanium · CPC title