CN107723510A - High-strength high-plasticity beta-titanium alloy with TRIP/TWIP effects and preparation method thereof - Google Patents

Abstract

A high-strength and high-plasticity β-titanium alloy with TRIP/TWIP effect, mainly composed of the following components in mass percentage: Mo 10%-14%, Zr 1%-10%, or Mo 10%-14%, Sn 1 %~5%, or Mo 10%~14%, Fe 0.5%~1.5%, or Mo 10%~14%, Zr 1%~10%, Sn 1%~5%, Fe 0.5%~1.5%; The amount is Ti and unavoidable impurities. The present invention adjusts the beta stability of the beta titanium alloy so that TRIP and TWIP effects can be produced simultaneously in the process of plastic deformation at room temperature, showing excellent plasticity, high strength, good work hardening behavior and excellent cold working Performance and other comprehensive mechanical properties, has a good prospect of popularization and application.

Description

High-strength and high-plasticity β-titanium alloy with TRIP/TWIP effect and preparation method thereof

technical field

The invention relates to the field of titanium alloys, in particular to a high-strength and high-plastic metastable beta (beta) titanium alloy with TRIP/TWIP effect.

Background technique

Due to its low density, high specific strength, high specific modulus, good low temperature performance, good corrosion resistance, non-magnetic, good biocompatibility and other excellent comprehensive properties, titanium alloys are widely used in aerospace, automotive, petrochemical, medical equipment, etc. It has been widely used in the field of national economy. Among titanium alloys, β (beta) titanium alloys are currently the most widely used type of titanium alloys. Such as high-strength structure β titanium alloy Ti-15Mo-2.6Nb-3Al-0.2Si (β-21S), Ti-10V-2Fe-3Al (Ti-1023), Ti-5Al-5V-5Mo-1Cr-1Fe (BT22 ), Ti-15V-3Cr-3Sn-3Al (Ti-153) and other materials to replace some aluminum alloys, high-strength steels, etc., are used in wing beams, connecting joints, fastenings of large aircraft such as Boeing 777 and Airbus A380 parts, reinforced frames/beams, joint lugs, engine brackets, landing gear and other components.

Although the currently commonly used structural titanium alloys have high strength, such as β-21S, Ti-153, β-C, BT22 and other titanium alloys, their strength levels are between 1100 and 1250 MPa, and the fracture toughness KIC is between 45 and 60 MPa. However, compared with stainless steel or Co-Cr alloys, titanium alloys have two obvious disadvantages: low plasticity and poor work hardening ability. For example, their uniform plastic deformation capacity (ε) is generally lower than 25%, and the average work hardening range is about 80MPa. These two shortcomings severely limit the application and development of titanium alloys in high-strength and high-plastic environments. Therefore, it is of great scientific significance and application value to develop and design a new generation of titanium alloys with high strength, high plasticity and good work hardening ability, and to find out the formation mechanism of alloy products during deformation and the influence of deformation products on alloy properties.

Contents of the invention

In order to overcome the deficiencies of low plasticity and poor work hardening behavior of titanium alloys used in existing structures, the present invention provides a high-strength and high-plasticity beta titanium alloy with TRIP/TWIP effect and its preparation method to obtain a high-strength, high-plasticity and Ti-Mo based metastable β-titanium alloy with TRIP/TWIP effect and good work hardening ability.

The technical scheme that the present invention solves its technical problem adopts is:

A high-strength and high-plastic beta titanium alloy with TRIP/TWIP effect is mainly composed of the following components in mass percentage: Mo 10%-14%, Zr 1%-10%, and the balance is Ti and unavoidable impurities.

Preferably, it consists of the following components in weight percentage: Mo 12%, Zr 5%, the balance being Ti and unavoidable impurities.

Further, the following components in mass percentage are also included: 0.5%-1.5% of Fe or 1%-5% of Sn.

Preferably, it consists of the following components in weight percentage: Mo 12%, Zr 5%, Sn 3%, the balance being Ti and unavoidable impurities.

A high-strength and high-plasticity β-titanium alloy with TRIP/TWIP effect is mainly composed of the following components in mass percentage: Mo 10%-14%, Sn 1%-5%, and the balance is Ti and unavoidable impurities.

Preferably, it consists of the following components in weight percentage: Mo 12%, Sn 5%, the balance being Ti and unavoidable impurities.

Further, the following components in mass percentage are also included: 0.5%-1.5% of Fe.

A high-strength and high-plastic beta titanium alloy with TRIP/TWIP effect mainly consists of the following components in mass percentage: Mo 10%-14%, Fe 0.5%-1.5%, and the balance is Ti and unavoidable impurities.

Preferably, it consists of the following components in weight percentage: Mo 10%, Fe 1.0%, the balance being Ti and unavoidable impurities.

A high-strength and high-plasticity β-titanium alloy with TRIP/TWIP effect, mainly composed of the following components in mass percentage: Mo 10%-14%, Zr 1%-10%, Sn 1%-5%, Fe 0.5%- 1.5%, the balance is Ti and unavoidable impurities.

The present invention prepares a Ti-Mo-based high-strength and high-plasticity beta titanium alloy with TRIP/TWIP effect by regulating the beta stability of the beta titanium alloy, so that TRIP and TWIP effects (TRIP: Plastic deformation induced by phase change, TWIP: twin crystal induced plastic deformation), showing excellent plasticity (uniform plastic deformation capacity ε≥30%), high strength (tensile strength UTS: 900 ~ 1200MPa), good Excellent work hardening behavior (work hardening interval exceeds 200MPa) and excellent cold workability (cold rolling deformation rate ≥ 95%) and other comprehensive mechanical properties (as shown in Figure 1). This series of Ti-Mo-based titanium alloys, and Ti- Compared with 6Al-4V alloy (annealed state), although its yield strength is lower than that of Ti-6Al-4V alloy, its uniform plastic deformation rate is almost 4 times that of Ti-6Al-4V alloy; and compared to 'Gum alloy', The designed alloy has better strength and plasticity; compared with 18.8% MnTRIP/TWIP steel, although the plasticity of this series of alloys is lower than that of 18.8% Mn steel, the yield strength of this alloy is higher than that of 18.8% Mn steel. Thus, Compared with the traditional structure titanium alloy, this new structure titanium alloy has more excellent performance, which can improve the performance of titanium alloy parts, save resources, improve production efficiency and material utilization. Therefore, it has a good prospect for promotion and application. Will bring greater economic and social benefits.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is the true stress-strain curve of some typical Ti-Mo based TRIP/TWIP titanium alloys of the present invention.

Figure 2(a)-(e) are the true stress-strain curves and work hardening rate curves of Ti-Mo-based TRIP/TWIP titanium alloys with different compositions according to the present invention.

Fig. 3 is the XRD pattern of Ti-12Mo-5Zr alloy before and after deformation.

Figure 4 is the EBSD diagram of Ti-12Mo alloy at the time of deformation ε=0.015, (a) is contrast mapping; (b) is inverse pole figure.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1:

1. Weigh each component: according to the weight percentage of each element, it is composed of 12% Mo, the balance is Ti and unavoidable impurities, respectively weigh sponge titanium, high-purity molybdenum and pure zirconium as raw materials; 2. Prepare a monolithic electrode : Prepare the raw material of step 1 into a monolithic electrode; 3. Prepare consumable electrode: assemble and weld the monolithic electrode prepared in step 2 into a self-consumable electrode in a vacuum welding box; 4. Prepare ingot: prepare step 3 The prepared consumable electrode is smelted three times in a vacuum consumable electric arc furnace to prepare an ingot; 5. Prepare cold-rolled samples: cut cold-rolled samples of appropriate size from the ingot prepared in step 4 with a wire-cut electric discharge machine. The sample is then subjected to solution treatment in a vacuum quenching furnace, followed by water quenching; 6. Cold rolling + solution treatment: the cold-rolled sample prepared in step 5 is repeatedly cold-rolled to the desired temperature in a double-roll cold-rolling equipment at room temperature. The size is required, and then solid solution treatment is carried out in a vacuum quenching furnace, followed by water quenching to obtain Ti-12Mo (wt.%) titanium alloy.

Example 2:

One, take each component by weighing: form 12% Mo, 5% Zr by weight percentage of each element, surplus is Ti and unavoidable impurity and take sponge titanium, high-purity molybdenum and pure zirconium respectively as raw material; Two, Preparation of monolithic electrodes: prepare the raw materials in step 1 into monolithic electrodes; 3. Prepare consumable electrodes: assemble and weld the monolithic electrodes prepared in step 2 into consumable electrodes in a vacuum welding box; 4. Prepare ingots : The consumable electrode prepared in step 3 is smelted three times in a vacuum consumable electric arc furnace to prepare an ingot; five, prepare a cold-rolled sample: cut a suitable ingot from the ingot prepared in step 4 with a wire-cut electric discharge machine The cold-rolled sample of the same size is then subjected to solution treatment in a vacuum quenching furnace, followed by water quenching; 6. Cold rolling + solution treatment: the cold-rolled sample prepared in step 5 is repeatedly carried out in a two-roll cold-rolling equipment at room temperature Cold rolling to the desired size, and then solution treatment in a vacuum quenching furnace, followed by water quenching to obtain Ti-12Mo-5Zr (wt.%) titanium alloy.

Example 3:

One, take each component by weighing: form 12% Mo, 5% Sn by the weight percentage of each element, surplus is Ti and unavoidable impurity and take sponge titanium, high-purity molybdenum and pure tin respectively as raw material; Two, Preparation of monolithic electrodes: prepare the raw materials in step 1 into monolithic electrodes; 3. Prepare consumable electrodes: assemble and weld the monolithic electrodes prepared in step 2 into consumable electrodes in a vacuum welding box; 4. Prepare ingots : The consumable electrode prepared in step 3 is smelted three times in a vacuum consumable electric arc furnace to prepare an ingot; five, prepare a cold-rolled sample: cut a suitable ingot from the ingot prepared in step 4 with a wire-cut electric discharge machine The cold-rolled sample of the same size is then subjected to solution treatment in a vacuum quenching furnace, followed by water quenching; 6. Cold rolling + solution treatment: the cold-rolled sample prepared in step 5 is repeatedly carried out in a two-roll cold-rolling equipment at room temperature Cold rolling to the desired size, and then solution treatment in a vacuum quenching furnace, followed by water quenching to obtain Ti-12Mo-5Sn (wt.%) titanium alloy.

Example 4:

One, take each component by weighing: form 12% Mo, 5% Sn by the weight percentage of each element, surplus is Ti and unavoidable impurity and take sponge titanium, high-purity molybdenum and pure tin respectively as raw material; Two, Preparation of monolithic electrodes: prepare the raw materials in step 1 into monolithic electrodes; 3. Prepare consumable electrodes: assemble and weld the monolithic electrodes prepared in step 2 into consumable electrodes in a vacuum welding box; 4. Prepare ingots : The consumable electrode prepared in step 3 is smelted three times in a vacuum consumable electric arc furnace to prepare an ingot; five, prepare a cold-rolled sample: cut a suitable ingot from the ingot prepared in step 4 with a wire-cut electric discharge machine The cold-rolled sample of the same size is then subjected to solution treatment in a vacuum quenching furnace, followed by water quenching; 6. Cold rolling + solution treatment: the cold-rolled sample prepared in step 5 is repeatedly carried out in a two-roll cold-rolling equipment at room temperature Cold rolling to the desired size, and then solution treatment in a vacuum quenching furnace, followed by water quenching to obtain Ti-12Mo-5Zr-3Sn (wt.%) titanium alloy.

Example 5:

One, take each component by weighing: form 10% Mo, 1% Fe by the weight percentage of each element, surplus is Ti and unavoidable impurity and take sponge titanium, high-purity molybdenum and iron nail respectively as raw material; Two, Preparation of monolithic electrodes: prepare the raw materials in step 1 into monolithic electrodes; 3. Prepare consumable electrodes: assemble and weld the monolithic electrodes prepared in step 2 into consumable electrodes in a vacuum welding box; 4. Prepare ingots : The consumable electrode prepared in step 3 is smelted three times in a vacuum consumable electric arc furnace to prepare an ingot; five, prepare a cold-rolled sample: cut a suitable ingot from the ingot prepared in step 4 with a wire-cut electric discharge machine The cold-rolled sample of the same size is then subjected to solution treatment in a vacuum quenching furnace, followed by water quenching; 6. Cold rolling + solution treatment: the cold-rolled sample prepared in step 5 is repeatedly carried out in a two-roll cold-rolling equipment at room temperature Cold rolling to the desired size, and then solution treatment in a vacuum quenching furnace, followed by water quenching to obtain Ti-10Mo-1Fe (wt.%) titanium alloy.

The following table provides the embodiments of various combinations of the present invention:

Mo Zr(%) 12+5 12+1 12+10 10+15 14+3 Mo Sn(%) 12+3 12+5 12+8 10+15 14+3 Mo Fe(%) 10+0.25 10+0.5 10+1 10+2 Mo Zr Sn (%) 12+5+3 12+3+5 12+5+5 10+8+8 14+3+3 Mo Zr Fe (%) 10+5+0.5 10+3+1 10+1+2 MoSnFe(%) 10+5+0.5 10+3+1 10+1+2 Mo Zr Sn Fe (%) 10+5+5+0.5 10+3+3+1

The mechanical properties of the designed alloy were tested by INSTRON universal tensile testing machine; SEM-EBSD, TEM/HRTEM, SEM/TEM+in-situ tensile and other characterization methods were used to analyze the structural characteristics of the alloy sample during plastic deformation. Mechanical results show that this series of alloys have excellent cold workability (cold rolling deformation rate>95%), high strength (tensile strength UTS: 900~1200MPa), excellent plasticity (uniform plastic deformation capacity ε≥30%) and good processing Hardening behavior (work hardening interval over 200MPa) of Ti-Mo based metastable β-titanium alloys (Fig. 1 and Fig. 2). Microstructural analysis shows that this series of Ti-Mo-based alloys is composed of a single β phase in the solid solution state, and this series of alloys produces slip, stress-induced martensitic transformation α″ and {332 }<113>Multiple deformation mechanisms such as mechanical twinning (Fig. 3 and Fig. 4), which lead to the above excellent properties of the alloy.

Figure 1 shows the true stress-strain curves of some typical Ti-Mo-based TRIP/TWIP titanium alloys, for comparison, the true stress-strain curves of Ti-6Al-4V alloy (annealed), 'Gum alloys' and 18.8%Mn TRIP/TWIP steel Strain curves are also plotted on this graph.

Figure 2 is the true stress-strain curve and work hardening rate curve of Ti-Mo based TRIP/TWIP titanium alloys with different compositions. Figure 2(a) is the work hardening rate curve of Ti-12Mo alloy; Figure 2(b) is the work hardening rate curve of Ti-12Mo-5Zr alloy; Figure 2(c) is the work hardening rate curve of Ti-12Mo-5S alloy Curve; Figure 2(d) is the work hardening rate curve of Ti-10Mo-1F; Figure 2(e) is the work hardening rate curve of Ti-12Mo-5Zr-3Sn.

Fig. 3 XRD pattern (X-ray diffraction pattern) of Ti-12Mo-5Zr alloy before and after deformation. The results show that the alloy is composed of β phase and a small amount of quenched ω phase in solid solution state (before deformation); after deformation, a large amount of stress induces martensite α″.

Figure 4 is the EBSD (electron backscattering diffraction analysis technique) diagram of Ti-12Mo alloy at the time of deformation ε = 0.015, Figure 4 (a) contrast mapping (orientation comparison); Figure 4 (b) inverse pole figure (reverse pole figure ). It can be seen that stress-induced {332}<113>twinning and stress-induced martensitic transformation occur simultaneously during the deformation process.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any form. Any simple modifications and equivalent changes made to the above embodiments according to the technical essence of the present invention shall fall within the scope of the present invention. within the scope of protection of the invention.

Claims (10)

1. A high-strength and high-plasticity beta titanium alloy with TRIP/TWIP effect is characterized in that it is mainly composed of the following components in mass percentage: Mo 10%～14%, Zr1%～10%, and the balance is Ti and unavoidable impurities. 2. The high-strength and high-plasticity beta titanium alloy with TRIP/TWIP effect according to claim 1 is characterized in that: it is made up of the composition of following percentage by weight: Mo 12%, Zr 5%, surplus is Ti and must not Avoid impurities. 3. The high-strength and high-plasticity β-titanium alloy with TRIP/TWIP effect according to claim 1 or 2, characterized in that: it also includes the following components in mass percentage: 0.5% to 1.5% of Fe or 1% to 5% of Sn %. 4. The high-strength and high-plasticity beta titanium alloy with TRIP/TWIP effect according to claim 3 is characterized in that: it is composed of the following components in weight percentage: Mo 12%, Zr 5%, Sn 3%, the balance For Ti and unavoidable impurities. 5. A high-strength and high-plasticity beta titanium alloy with TRIP/TWIP effect, characterized in that it is mainly composed of the following components in mass percentage: Mo 10%-14%, Sn 1%-5%, and the balance is Ti and unavoidable impurities. 6. The high-strength and high-plasticity beta titanium alloy with TRIP/TWIP effect according to claim 5 is characterized in that: it is made up of the composition of following percentage by weight: Mo 12%, Sn 5%, surplus is Ti and must not Avoid impurities. 7. The high-strength and high-plasticity β-titanium alloy with TRIP/TWIP effect according to claim 5 or 6, characterized in that: it also includes the following composition in mass percentage: 0.5%-1.5% Fe. 8. A high-strength and high-plasticity β-titanium alloy with TRIP/TWIP effect, characterized in that it is mainly composed of the following components in mass percentage: Mo 10% to 14%, Fe 0.5% to 1.5%, and the balance is Ti and unavoidable impurities. 9. The high-strength and high-plasticity beta titanium alloy with TRIP/TWIP effect according to claim 8 is characterized in that: it is composed of the following components in weight percentage: Mo 10%, Fe 1.0%, and the balance is Ti and not Avoid impurities. 10. A high-strength and high-plasticity β-titanium alloy with TRIP/TWIP effect, characterized in that it is mainly composed of the following components in mass percentage: Mo 10%-14%, Zr1%-10%, Sn 1%-5 %, Fe 0.5% to 1.5%, and the balance is Ti and unavoidable impurities.