TB2 Overview
TB2 alloy is a metastable material β Type titanium alloy, containing isomorphic form β Stable elements 5% Mo and 5% V, eutectoid type β Stable element 8% Cr, α The stable element is 3% Al, with a Mo equivalent of 18.15. This alloy has excellent cold forming performance and good welding performance in the solution treated state, and has high strength and good plasticity matching in the solution aged state. The main drawbacks of this alloy are its high density, low elastic modulus, and low resistance to high-temperature creep.
The main semi-finished products of this alloy include plates, strips, foils, bars, wires, etc. Sheet metal can be made into sheet metal parts, pressure vessels, and solid rocket engine shells. The strip can be made into a star arrow connection strip. Foil can be made into corrugated shells and honeycomb structures. Wire can be cold riveted to produce various head type rivets, and can be cold riveted and hot riveted. The rivets can be directly used after being riveted in a solution treated state. Bars can be cold upset to produce various head bolts and can be used in solution treated or solution aged conditions.
This alloy is suitable for manufacturing aerospace fasteners that work below 300 ℃, as well as aerospace fasteners that work for short periods below 500 ℃.
TB2 Technical Standards
GB/T 3620.1-1994 "Titanium and Titanium Alloy Grades and Chemical Composition"
GB/T 3620.2-1994 "Chemical Composition and Permissible Variations in Composition of Titanium and Titanium Alloy Processed Products"
GB/T 3621-1994 "Titanium and Titanium Alloy Plates"
K/JC 2-1984 "Provisional Technical Specification for TB2 Alloy Strip for Communication Satellite" Satellite Arrow Connection Belt "
GJB 2219-1994 "Specification for Titanium and Titanium Alloy Bars (Wire) for Fasteners"
TB2 heat treatment system
(1) Solid solution treatment
Select a solution treatment temperature within the range of 750-800 ℃, and the usual solution treatment system is 800 ℃± 10 ℃ for 3-30 minutes, air cooling or faster cooling.
(2) Timeliness
The aging temperature is selected within the range of 450-550 ℃, and the usual aging system is 500 ℃± 10 ℃, 8-24 hours, air cooling or furnace cooling.
(3) Stress relieving annealing
650-700 ℃, 30-60 minutes, air-cooled or furnace cooled.
TB2 melting and casting process
The alloy should be melted in a vacuum consumable electrode arc furnace more than twice.
TB2 Application Overview and Special Requirements
Various specifications of star arrow connection belts made of TB2 alloy strips have been used for a long time in the aerospace industry. Various head type rivets made of TB2 alloy wire through cold heading have been applied in the aviation industry. Bars can be cold upset to produce various bolts such as inner hexagonal, outer hexagonal, and countersunk heads, which can be used in the aviation and aerospace industries. The service temperature for the solution treatment state is below 200 ℃, and the service temperature for the solution aging state is below 300 ℃.
TB2 corrosion resistance
TB2 alloy has good corrosion resistance and contact corrosion resistance. Stainless steel does not produce corrosion in contact with it. Aluminum alloy and structural steel come into contact with it, and the alloy itself does not corrode. Instead, dissimilar metals are corroded. The alloy is anodized and has little effect on its mechanical properties, but it can slow down the corrosion rate of structural steel and aluminum alloy in contact with it.
