Heat treatment method for obtaining high-toughness and high-damage-tolerance dual-phase titanium alloy

A heat treatment method and damage tolerance technology, applied in the field of titanium alloys, can solve the problems of difficulty in taking into account the strength and toughness and damage tolerance performance, the deterioration of titanium alloy toughness and damage tolerance performance, and the reduction of alloy strength, so as to improve the toughness. and damage tolerance performance, low fatigue crack growth rate, high fracture toughness effect

A heat treatment method and damage tolerance technology, applied in the field of titanium alloys, can solve the problems of difficulty in taking into account the strength and toughness and damage tolerance performance, the deterioration of titanium alloy toughness and damage tolerance performance, and the reduction of alloy strength, so as to improve the toughness. and damage tolerance performance, low fatigue crack growth rate, high fracture toughness effect

CN113249667AActive Publication Date: 2021-08-13北京煜鼎增材制造研究院股份有限公司

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] The material of this embodiment is additively manufactured TC11 titanium alloy, the maximum thickness of which is 20mm, and its β transformation temperature T β The temperature is 1010°C, adopt the following high-temperature heat treatment process: 1007°C, heat preservation for 0.5 hours, and control the cooling rate at 20±5°C / s within the temperature range of cooling to 800°C. Additively manufactured TC11 titanium alloy material after treatment, room temperature strength R m 1070MPa; room temperature fracture toughness K IC 115MPa·m 1 / 2 , which is about 53% higher than that before treatment; the fatigue crack growth rate da / dN in the steady-state region is significantly lower than that before treatment, when Δ K =15 MPa·m 1 / 2 , da / dN decreased by about 53%.

Embodiment 2

[0019] The material of this embodiment is TC11 titanium alloy forging, its maximum thickness is 40mm, and its β transformation temperature T β The temperature is 1010°C, the original structure is forged two-state structure, and the following pretreatment process is adopted: at 1020°C, heat preservation for 1 hour, and the cooling rate is controlled at 150±20°C / s; then high-temperature heat treatment, high-temperature heat treatment process: 1007°C, heat preservation 0.5 Hours, the cooling rate is controlled at 20±5°C / sec in the temperature range of high temperature cooling to 800°C. After treatment, TC11 titanium alloy forgings, room temperature strength R m 1060MPa, room temperature fracture toughness K IC 105MPa·m 1 / 2 , which is about 38% higher than that before treatment; the fatigue crack growth rate da / dN in the steady-state region is significantly lower than that before treatment, when Δ K =15 MPa·m 1 / 2 , da / dN decreased by about 39%.

Embodiment 3

[0021] The material of this embodiment is TC4 titanium alloy casting, its maximum thickness is 18mm, and its β transformation temperature T β The temperature is 995°C, the original tissue is Widmanstatten tissue, and the following high-temperature heat treatment process is adopted: 992°C, heat preservation for 1 hour, and the cooling rate is controlled at 30±5°C / sec within the temperature range of high temperature cooling to 790°C. Treated TC4 casting, room temperature strength R m 905MPa, room temperature fracture toughness K IC 90.5MPa·m 1 / 2 , which is about 15% higher than that before treatment; the fatigue crack growth rate in the steady-state region is significantly lower than that before treatment, when Δ K =15 MPa·m 1 / 2 , da / dN decreased by about 28%.

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Abstract

The invention discloses a heat treatment method for obtaining a high-toughness and high-damage-tolerance double-phase titanium alloy. The heat treatment method comprises the following steps of high-temperature annealing treatment, specifically, keeping the temperature for 0.1-2 hours at T1 temperature, reasonably controlling the cooling speed, preferably, controlling the temperature range from T1 to T-200 DEG C to be 2-50 DEG C / s, controlling the value range of T1 between Tbeta10 DEG C and T, controlling the value range of T between Tbeta10 DEG C and T, controlling the value range of T between Tbeta10 DEG C and T, wherein T is the beta transformation temperature of the double-phase titanium alloy. According to the method, the toughness and the damage tolerance performance of the double-phase titanium alloy are improved by controlling the heat treatment temperature and the cooling speed. The method can be used for the two-phase titanium alloy with two structures under the room temperature conditions of TC11, TA15, TC4, TC17, TC18 and the like, is not limited by the original manufacturing process of the titanium alloy, and is suitable for forge pieces, castings, welding pieces and additive manufacturing pieces of the two-phase titanium alloy.

Description

technical field [0001] The invention relates to the field of titanium alloys, in particular to a heat treatment method for obtaining a dual-phase titanium alloy with high toughness and high damage tolerance. Background technique [0002] Based on the damage tolerance design concept of structural safety, structural materials such as titanium alloys are developed in the direction of high toughness and high damage tolerance. Titanium alloys with high toughness and high damage tolerance have become the focus of research in the field of titanium alloys. The most widely used high toughness and high damage tolerance titanium alloy in foreign countries is TC4ELI, and the high toughness and high damage tolerance titanium alloy used in my country is TC4DT. High damage tolerance characteristics, due to the reduction of oxygen and nitrogen elements, the strength of the alloy is reduced, and its ultimate strength is less than 900MPa. Since the strength of titanium alloys mainly depends o...

Claims

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Application Information

Patent Timeline
13 Aug 2021
Publication
CN113249667A
IPC
C22F1/18
CPC
C22F1/183
Inventors
不公告发明人