Method for acquiring tri-modal microstructure in near-alpha titanium alloy

Abstract

The invention relates to a method for acquiring a tri-modal microstructure in a near-alpha titanium alloy. Near-beta temperature heat treatment is carried out to change the sample microstructure into alpha-equiaxial+martensite; two-phase region temperature heat treatment is carried out to change the sample microstructure into alpha-equiaxial+alpha sliver+beta-rotation; and aging treatment is carried out to obtain the titanium alloy with tri-modal microstructure. The invention does not need near-beta thermal deformation, does not generate deformation temperature rise effect, can easily controlthe temperature, and does not need to carry out special pretreatment on the equiaxial-structure near-alpha titanium alloy to acquire the duplex microstructure. The invention is simple and easy to implement, has wide application range, and is suitable for heat treatment on near-alpha titanium alloy parts manufactured by rolling, extrusion, machining and other formation methods to acquire the tri-modal microstructure. Especially for the titanium alloy complex components, partial complex components or large-size components, after processing the near net shape of the component, the method can be utilized to acquire the tri-modal microstructure.

Description

technical field [0001] The invention relates to the technical field of thermal processing of titanium alloys, in particular to a method for obtaining a triple-state structure of a near-alpha titanium alloy through heat treatment. Background technique [0002] Near-α titanium alloys have better thermal stability and weldability than α+β-type titanium alloys, and better pressure processing performance than α-titanium alloys. They are usually used in key load-bearing structural parts in aviation, aerospace and other fields. The service environment of these components is harsh, not only require high precision, but also require high performance and high reliability, that is to say, not only require good room temperature plasticity and thermal stability, but also require good strength, high temperature performance (durability, creep), Fracture toughness, fatigue properties, crack growth resistance. Near-alpha titanium alloy rods, plates or forging billets (melted, rolled or refor...

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Problems solved by technology

[0004] In order to overcome the shortcomings of near-β forging in the prior art that may cause the local temperature of the forging to be too high due to the thermal effect of uneven deformation, or make the forging control more complicated, and limit the initial structure to a two-state structure, the present invention proposes A Method for Obtaining Triple-state Microstructure in Near-α Titanium Alloy

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