Titanium alloy dendrite arm spacing process

Abstract

The application relates to the technical field of titanium alloy processing technology, in particular to a titanium alloy crystallization ice flower process, after titanium alloy is smelted to obtain a titanium alloy casting blank, the titanium alloy casting blank is subjected to at least twice of heat preservation treatment, a secondary alloy blank is obtained, each heat preservation treatment is divided into two stages of high and low temperatures, through the heat preservation treatment of multiple stages, the titanium alloy is rearranged, a more regular and ordered crystal structure is formed, a crystallized titanium alloy is obtained, and the titanium alloy is taken out after being filled with inert gas and cooled to room temperature; the process generates ice flowers with a size of 2cm-7cm on the titanium alloy through multiple heat preservation treatments, and the strength and toughness and other performances of the titanium alloy are improved.

Description

Technical Field

[0001] This invention relates to the field of titanium alloy crystallization technology, specifically a titanium alloy crystallization ice flower process. Background Technology

[0002] Titanium and titanium alloys have a wide range of applications, spanning marine engineering, aerospace, biomedical engineering, metallurgy, chemical engineering, light industry, and many other fields. With the widespread use of titanium and titanium alloys, the development of industry and the service environment have placed more stringent demands on the performance of titanium alloys. Traditional titanium alloys are finding it increasingly difficult to meet current engineering standards in terms of strength and corrosion resistance. Therefore, high-strength, corrosion-resistant titanium alloys are one of the key areas of research, development, and application.

[0003] Market demand necessitates titanium alloys with larger crystal ice flowers and better material properties.

[0004] To this end, a crystallization ice flower process for titanium alloys was studied. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a titanium alloy crystallization ice flower process that not only generates large-sized crystallization ice flowers in titanium alloys but also improves the final material properties of the titanium alloy.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A titanium alloy crystallization ice flower process, characterized by specifically including the following steps: Step S1: Melt the alloy raw materials to obtain a titanium alloy billet; Step S2: Perform crystallization on the titanium alloy billet to obtain a secondary alloy billet. The crystallization process includes at least two heat preservation treatments. Each heat preservation treatment is divided into two stages: a high temperature stage and a low temperature stage, which causes large-sized crystal ice flowers to form on the secondary alloy billet. Step S3: Perform deformation and solution treatment on the secondary alloy billet to obtain a crystalline titanium alloy; Step S4: After cooling the crystalline titanium alloy to room temperature by filling it with inert gas, remove it.

[0007] Optionally, in one embodiment of the present invention, the crystallization process includes heating and four holding treatments. The heating is performed to 1020℃±5℃. The first holding treatment has a high temperature stage of 1020℃±5℃ and a holding time of 80min±5min, and a low temperature stage of 750℃±5℃ and a holding time of 80min±5min. The second holding treatment has a high temperature stage of 1050℃±5℃ and a holding time of 80min±5min, and a low temperature stage of 750℃±5℃ and a holding time of 80min±5min. The third holding treatment has a high temperature stage of 1020℃±5℃ and a holding time of 90min±5min, and a low temperature stage of 750℃±5℃ and a holding time of 80min±5min. The fourth holding treatment has a high temperature stage of 1020℃±5℃ and a holding time of 90min±5min, and a low temperature stage of 500℃±5℃ and a holding time of 30min±5min.

[0008] Optionally, in one embodiment of the present invention, the alloy raw material comprises Al 4-6.0%, V 1.5-4%, Sn 3.7-4.7%, Mo 0.75-2.0%, Si 0.02-0.4%, Zr 5-45%, and the remainder being titanium.

[0009] Optionally, in one embodiment of the present invention, in step S3, the deformation treatment is multi-pass rolling, the deformation amount of each pass is 15%-20%, and the rolling deformation temperature is 900℃-1050℃.

[0010] Optionally, in one embodiment of the present invention, the heat preservation temperature of the solution treatment is 900℃-1050℃, and the heat preservation time of the solution treatment is 3 minutes.

[0011] Optionally, in one embodiment of the present invention, in the multi-pass rolling, the secondary alloy billet needs to be cooled between two adjacent rolling passes, with a temperature of 550℃±20℃ and a holding time of 5min-10min.

[0012] Optionally, in one embodiment of the present invention, the inert gas is either argon or nitrogen.

[0013] Optionally, in one embodiment of the present invention, the large-sized ice flower is an irregular crystalline ice flower with a length of 2cm-7cm.

[0014] Beneficial effects of the invention The present invention discloses a titanium alloy crystallization ice flower process. The alloy raw materials include aluminum, vanadium, and zirconium, which can play a role in refining the titanium alloy. After multiple high and low temperature stages of heat preservation treatment, large-sized crystal ice flowers are generated in the titanium alloy, and the titanium alloy is ultimately strengthened in terms of strength, toughness, and plasticity. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0016] Figure 1 This is a process flow diagram of Embodiment 1 of the present invention. Detailed Implementation

[0017] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structure, features and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below. Example 1

[0018] To meet the requirements for larger crystallization ice flowers and improve the performance of titanium alloy materials, a titanium alloy crystallization ice flower process was designed, and the specific scheme is as follows: like Figure 1 As shown, a titanium alloy crystallization ice flower process is characterized by the following steps: Step S1: Melt the alloy raw materials to obtain a titanium alloy billet; Step S2: Perform crystallization on the titanium alloy billet to obtain a secondary alloy billet. The crystallization process includes at least two heat preservation treatments. Each heat preservation treatment is divided into two stages: a high temperature stage and a low temperature stage, which causes large-sized crystal ice flowers to form on the secondary alloy billet. Step S3: Perform deformation and solution treatment on the secondary alloy billet to obtain a crystalline titanium alloy; Step S4: After cooling the crystalline titanium alloy to room temperature by filling it with inert gas, remove it.

[0019] The crystallization process includes heating and four holding treatments. The heating is performed to 1020℃±5℃. The first holding treatment has a high temperature stage of 1020℃±5℃ and a holding time of 80min±5min, and a low temperature stage of 750℃±5℃ and a holding time of 80min±5min. The second holding treatment has a high temperature stage of 1050℃±5℃ and a holding time of 80min±5min, and a low temperature stage of 750℃±5℃ and a holding time of 80min±5min. The third holding treatment has a high temperature stage of 1020℃±5℃ and a holding time of 90min±5min, and a low temperature stage of 750℃±5℃ and a holding time of 80min±5min. The fourth holding treatment has a high temperature stage of 1020℃±5℃ and a holding time of 90min±5min, and a low temperature stage of 500℃±5℃ and a holding time of 30min±5min.

[0020] The alloy raw materials include Al 4-6.0%, V 1.5-4%, Sn 3.7-4.7%, Mo 0.75-2.0%, Si 0.02-0.4%, Zr 5-45%, and the remainder is titanium.

[0021] In this embodiment, the melting in step S1 is vacuum arc melting at a temperature of 2000°C. When melting the alloy raw materials, the furnace cavity needs to be evacuated and the vacuum level is kept below 8 Pa. Then, an inert gas is introduced. The inert gas is the same as the cooling gas, which is argon. The melting of the alloy raw materials is divided into multiple meltings, each melting is controlled within 5 minutes. The alloy raw materials used for melting are preferably low-impurity raw materials to improve product quality.

[0022] In this embodiment, the presence of Zr in the alloy raw materials causes lattice distortion, resulting in grain refinement of the titanium alloy. Zr can also form an infinite solid solution with titanium to achieve solid solution strengthening. Al can improve the strength of the titanium alloy, while simultaneously enhancing its plasticity and toughness through grain refinement. The solid solubility of aluminum differs in the α and β phases; it is greater in the β phase region than in the α phase region. Therefore, increasing the solid solubility of aluminum in the β phase region can promote the formation of the β phase, thereby promoting grain refinement. The presence of V, as a β phase stabilizing element, can increase the solid solubility of the β phase and slow down the phase transformation rate, thus promoting the precipitation of the β phase at the α phase grain boundaries, further promoting grain refinement. Furthermore, vanadium can form compounds with oxygen and nitrogen, reducing their content and further improving the mechanical properties of the titanium alloy. In step S3, the deformation treatment is a multi-stage rolling process, with each stage involving a deformation amount of 15%-20% and a rolling deformation temperature of 900℃-1050℃, which refines the grain size of the titanium alloy and improves its plasticity.

[0023] Specifically, the total deformation during multi-stage rolling is controlled at 60%-75% to obtain titanium alloy thin plates.

[0024] The solution treatment temperature is 900℃-1050℃, and the solution treatment time is 3 minutes.

[0025] Solution treatment must also be carried out under a protective atmosphere, which is argon. Solution treatment eliminates residual stress caused by deformation and improves plasticity.

[0026] In multi-pass rolling, the secondary alloy billet needs to be cooled between adjacent rolling passes at a temperature of 550℃±20℃ for 5-10 minutes. In this embodiment, multi-pass rolling is divided into three rolling stages. The first stage includes three to four rolling passes, with a deformation rate of 5%-15% per pass. The second stage includes four rolling passes, with a deformation rate of 8%-15% per pass. The third stage includes multiple rolling passes, with a deformation rate of 5%-7% per pass. By controlling the deformation amount of each rolling pass, the titanium alloy grains are made as fine as possible.

[0027] Through multiple rolling passes, titanium alloys acquire high strength and good toughness.

[0028] The inert gas can be either argon or nitrogen. In this embodiment, argon is used to fill the gas, which isolates oxygen, protects the titanium alloy from oxidation, and also improves the corrosion resistance of the titanium alloy.

[0029] Large-sized ice flowers are irregular crystalline ice flowers with a length of 2cm-7cm.

[0030] The crystallization process in this solution reduces the grain size of the titanium alloy through multiple heat treatments, improving its thermal stability and corrosion resistance. It also alters the internal phase composition, increasing the content of the β phase, thereby enhancing the strength and toughness of the titanium alloy. The titanium alloy produces larger crystal ice flowers, which, while meeting customer requirements, also strengthens the material properties of the titanium alloy to a certain extent.

[0031] Meanwhile, repeated heat treatments can alter the internal phase composition of titanium alloys, such as increasing the content of the β phase, thereby improving the strength and toughness of the titanium alloys. Example 2

[0032] In this embodiment, the process is basically the same as that in Example 1, except that the alloy raw materials include Al 4-6.0%, V 1.5-4%, Fe 3.7-4.7%, C 0.75-2.0%, Si 0.02-0.4%, Zr 5-45%, and the remainder is titanium.

[0033] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A titanium alloy crystallization ice flower process, characterized in that, Specifically, the following steps are included: Step S1: Melt the alloy raw materials to obtain a titanium alloy billet; Step S2: Perform crystallization on the titanium alloy billet to obtain a secondary alloy billet. The crystallization process includes at least two heat preservation treatments. Each heat preservation treatment is divided into two stages: a high temperature stage and a low temperature stage, which causes large-sized crystal ice flowers to form on the secondary alloy billet. Step S3: Perform deformation and solution treatment on the secondary alloy billet to obtain a crystalline titanium alloy; Step S4: After cooling the crystalline titanium alloy to room temperature by filling it with inert gas, remove it. The crystallization process includes heating and four holding treatments. The heating is performed to 1020℃±5℃. The first holding treatment has a high temperature stage of 1020℃±5℃ and a holding time of 80min±5min, and a low temperature stage of 750℃±5℃ and a holding time of 80min±5min. The second holding treatment has a high temperature stage of 1050℃±5℃ and a holding time of 80min±5min, and a low temperature stage of 750℃±5℃ and a holding time of 80min±5min. The third holding treatment has a high temperature stage of 1020℃±5℃ and a holding time of 90min±5min, and a low temperature stage of 750℃±5℃ and a holding time of 80min±5min. The fourth holding treatment has a high temperature stage of 1020℃±5℃ and a holding time of 90min±5min, and a low temperature stage of 500℃±5℃ and a holding time of 30min±5min. The alloy raw materials include Al 4-6.0%, V 1.5-4%, Sn 3.7-4.7%, Mo 0.75-2.0%, Si 0.02-0.4%, Zr 5-45%, and the remainder being titanium; The large-sized crystalline ice flowers are irregular crystalline ice flowers with a length of 2cm-7cm.

2. The titanium alloy crystallization ice flower process according to claim 1, characterized in that: In step S3, the deformation treatment is multi-pass rolling, with each pass having a deformation amount of 15%-20% and a rolling deformation temperature of 900℃-1050℃.

3. The titanium alloy crystallization ice flower process according to claim 1, characterized in that: The solution treatment is held at a temperature of 900℃-1050℃ for 3 minutes.

4. The titanium alloy crystallization ice flower process according to claim 2, characterized in that: In the multi-pass rolling process, the secondary alloy billet needs to be cooled between adjacent rolling passes at a temperature of 550℃±20℃ for a holding time of 5min-10min.

5. The titanium alloy crystallization ice flower process according to claim 1, characterized in that: The inert gas is either argon or nitrogen.

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