Titanium alloy stress relaxation test device and method based on V-type hot bending

Abstract

The invention discloses a titanium alloy stress relaxation test device and a titanium alloy stress relaxation test method based on V-type hot bending, belonging to the field of hot working of metals. The invention provides a load relaxation test device and a load relaxation test method based on V-type bending. A V-type bending loading test implemented in an electronic test machine can realize stress relaxation; the loading of a bending load for a sample placed between a bending convex die (5) and a bending concave die (6) is realized by use of the displacement provided by a beam (10), and a load sensor continuously records the bending load and the change of the load along with time in a shaping process; and in the condition of different shaping durations, different sample bending springback angles are obtained. The device and the method disclosed by the invention can test the change of the bending load along with time during hot shaping, can determine the rule of the load relaxing along with time under the condition with different shaping durations for a titanium alloy sample with the bending load while deriving the linear relation between load and sample stress, and can be widely applied to the field of hot working of metals.

Description

technical field [0001] The invention relates to a stress relaxation test method in plate thermal shape correction, in particular to a titanium alloy stress relaxation test device and method based on V-shaped thermal bending, and belongs to the field of metal thermal processing. Background technique [0002] Due to its good heat resistance, corrosion resistance and high specific strength, titanium alloys are widely used in aerospace and civil fields. However, titanium alloys have poor room temperature formability and severe springback, which increases the difficulty of producing workpieces with ideal and qualified shapes. . The hot forming of titanium alloy is one of the effective ways to reduce springback after sheet forming. The main principles include two: first, the ratio of yield strength to elastic modulus of titanium alloy at high temperature is reduced, and springback is reduced compared with room temperature forming; Second, the internal stress of the formed part de...

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Problems solved by technology

Tensile test is a common method for studying stress relaxation under load. It usually requires a closed-loop system to keep the strain constant during the stress relaxation process, which requires high equipment requirements, and the uniaxial tensile test is difficult to reflect the complex forming process of the sheet, such as bending and stretching. Wait

Standard bending tests at home and abroad have designed some devices to limit the shape of the sample. The residual stress is calculated according to the measured rebound (rebound distance, rebound radius) after stress relaxation, and the stress or load data cannot be directly measured.

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