Titanium-containing high-strength light steel MIM product and preparation method thereof
The titanium-containing high-strength lightweight steel MIM product prepared with aerosolized MIM powder of Fe-Mn-Al-C-Ti alloy solved the problem of difficult balance between lightweight and high strength in traditional materials, and achieved high mechanical properties at low density.
Patent Information
- Application Number
- CN202510196391.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-21
- Publication Date
- 2025-05-13
AI Technical Summary
Traditional high-strength lightweight steel materials are difficult to achieve a balance between lightweight and high strength, and cannot meet the special needs of consumer electronics, aerospace and other fields.
Fe-Mn-Al-C-Ti alloy aerosolized MIM powder is used as the basic material to prepare high-strength lightweight steel products containing titanium through MIM technology. The addition of titanium elements can reduce density and refine grains, thereby improving the product's yield strength, tensile strength and elongation after break.
At a lower average density, the mechanical properties of high-strength lightweight steel MIM products containing titanium are significantly improved, and the performance indicators of low density and high strength are achieved.
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Figure CN119980065A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of MIM product preparation, and in particular to a titanium-containing high-strength lightweight steel MIM product and a preparation method thereof. Background Art
[0002] With the rapid development of science and technology, green, low-carbon and sustainable development have put forward higher requirements on the traditional steel industry. Lightweight and miniaturization have gradually become the development trend of high-tech equipment such as consumer electronics, aerospace, automobiles, construction, drones, robots and 5G base stations. This also puts forward higher requirements on the material selection, structural design and manufacturing technology of high-tech equipment components.
[0003] However, when using traditional high-strength lightweight steel as the basic metal structural material, it is difficult to achieve a good balance between lightweight and high strength due to the high density and limited mechanical properties of the resulting products. Therefore, it cannot meet the special needs of applications in consumer electronics, aerospace, automobiles, construction and other fields.
[0004] New high-strength and lightweight metal structural materials represented by high-strength and lightweight steel, titanium alloy, high-strength aluminum alloy and magnesium alloy have lower density and better strength, and can be used as the preferred materials for lightweight parts of high-tech equipment. Metal Powder Injection Molding (MIM) technology can realize lightweight structural design of products and near-net shape manufacturing of small and complex shapes, and is suitable for mass production of high-strength and lightweight metal precision products with small and complex structures. Therefore, governments and scientific and technological industries attach great importance to the research and application of combining high-strength and lightweight metal structural materials with MIM technology. Summary of the invention
[0005] The purpose of this application is to improve the technical problems of MIM products in the prior art, and to provide a titanium-containing high-strength and lightweight steel MIM product and a preparation method thereof. The titanium-containing high-strength and lightweight steel MIM product uses Fe-Mn-Al-C-Ti alloy atomized MIM powder as the basic material. The addition of titanium element can reduce the density and refine the grains. The product is prepared using MIM technology to achieve the technical effect of improving the yield strength, tensile strength and elongation after fracture of the titanium-containing high-strength and lightweight steel MIM product.
[0006] The technical solution of this application In the first aspect, the present application provides a titanium-containing high-strength lightweight steel MIM product, which adopts the following technical solution: A titanium-containing high-strength lightweight steel MIM product, wherein the powder raw material used in its preparation is Fe-Mn-Al-C-Ti alloy gas atomized MIM powder; The Fe-Mn-Al-C-Ti alloy gas atomized MIM powder, calculated by mass percentage, has the following contents of Fe, Mn, Al, C and Ti: Mn 31-33% Al 11-13% C 0.8-1.2% Ti 0.1-1.0% The balance is Fe; The D50 of the Fe-Mn-Al-C-Ti alloy gas atomized MIM powder is 5-20 μm.
[0007] By adopting the above technical solution, titanium is a strong carbide-forming element. Titanium can form TiC (titanium carbide) particles with carbon. TiC particles can serve as the core of non-spontaneous nucleation during the metal solidification process. When the liquid metal begins to solidify, the liquid metal atoms attach to the core of the TiC particles to form crystals, which increases the number of crystal nuclei. The higher the nucleation rate, the finer the grains, so as to achieve the effect of grain refinement and dispersion strengthening. The average density of the titanium-containing high-strength lightweight steel MIM product made of Fe-Mn-Al-C-Ti alloy atomized MIM powder is 6.00-6.26g / cm 3 The average yield strength is 889.5-1040.5MPa, the average tensile strength is 978.2-1120.5MPa, and the average elongation after break is 5.4%-10.3%. That is, the obtained titanium-containing high-strength and lightweight steel MIM products can improve their mechanical properties at a lower average density, so that the obtained titanium-containing high-strength and lightweight steel MIM products have the performance indicators of low density and high strength.
[0008] Preferably, the Fe-Mn-Al-C-Ti alloy atomized MIM powder used for preparing the titanium-containing high-strength lightweight steel MIM product has the following contents of Fe, Mn, Al, C and Ti calculated by mass percentage: Mn 31-33% Al 11-13% C 0.8-1.2% Ti 0.1%-0.7% The balance is Fe; The D50 of the Fe-Mn-Al-C-Ti alloy gas atomized MIM powder is 5-20 μm.
[0009] Preferably, the Fe-Mn-Al-C-Ti alloy atomized MIM powder used for preparing the titanium-containing high-strength lightweight steel MIM product has the following contents of Fe, Mn, Al, C and Ti calculated by mass percentage: Mn 32% Al 12% C 0.9% Ti 0.1%-0.7% The balance is Fe; The D50 of the Fe-Mn-Al-C-Ti alloy gas atomized MIM powder is 5-20 μm.
[0010] Preferably, the Fe-Mn-Al-C-Ti alloy atomized MIM powder used for preparing the titanium-containing high-strength lightweight steel MIM product has the following contents of Fe, Mn, Al, C and Ti calculated by mass percentage: Mn 32% Al 12% C 0.9% Ti 0.5% The balance is Fe; The D50 of the Fe-Mn-Al-C-Ti alloy gas atomized MIM powder is 5-20 μm.
[0011] Preferably, the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder used in the preparation of the titanium-containing high-strength lightweight steel MIM product is commissioned to be prepared by Hunan Hengji Powder Technology Co., Ltd.
[0012] In a second aspect, the present application provides a method for preparing a titanium-containing high-strength lightweight steel MIM product, using the following technical solution: A method for preparing a titanium-containing high-strength lightweight steel MIM product specifically comprises the following steps: The Fe-Mn-Al-C-Ti alloy gas atomized MIM powder is sequentially granulated, injection molded and catalytically degreased, and the degreased blank is then sequentially pre-sintered, sintered, solution treated and aged to obtain a titanium-containing high-strength lightweight steel MIM product; In the pre-sintering process, the debinded blank is pre-sintered at a temperature of 500-900° C. for 1-3 hours to obtain a pre-sintered blank; In the sintering process, the pre-sintered blank is sintered for 1-3 hours under the protection of an inert gas at a temperature of 1250-1270° C. to obtain a sintered blank; the inert gas is argon; The solution treatment is controlled at a temperature of 1050-1100°C and a time of 0.5-1.5h; The aging treatment is carried out at a controlled temperature of 470-550°C and a time of 0.5-6.0h.
[0013] By adopting the above technical scheme, sintering, solution treatment and aging treatment can dissolve some carbides back into the matrix, thereby reducing the amount of coarse carbides in the microstructure of titanium-containing high-strength and lightweight steel MIM products, eliminating stress concentration points inside the titanium-containing high-strength and lightweight steel MIM products, and further improving the mechanical properties of the titanium-containing high-strength and lightweight steel MIM products; the preparation method of titanium-containing high-strength and lightweight steel MIM products adopts MIM technology, which can accurately control the composition and content of each raw material, thereby achieving a one-to-one correspondence between the sintering temperature and the average density, so that the obtained titanium-containing high-strength and lightweight steel MIM products can achieve low-density and high-strength performance indicators.
[0014] Preferably, the granulation comprises the following specific steps: The Fe-Mn-Al-C-Ti alloy atomized MIM powder is kneaded, mixed and granulated with a plastic-based binder, and the mixing process temperature is controlled at 185-195°C to obtain particles of a titanium-containing high-strength lightweight steel MIM product; The amount of the Fe-Mn-Al-C-Ti alloy atomized MIM powder and the plastic-based binder is calculated by volume ratio, Fe-Mn-Al-C-Ti alloy atomized MIM powder: plastic-based binder is 1:0.4-1; The plastic-based adhesive is a polyoxymethylene (POM) adhesive.
[0015] Preferably, the injection molding comprises the following specific steps: The particles of the titanium-containing high-strength lightweight steel MIM product obtained by the granulation are injected into a mold, and after pressure maintenance, cooling and solidification, the mold is opened to take out the injection blank; During the particle injection process of the titanium-containing high-strength lightweight steel MIM product, the injection temperature is controlled at 170-210°C and the injection speed is controlled at 35-85cm 3 / s and injection pressure 60-120MPa; The holding pressure is 60-120 MPa and the holding time is 2-10 s; The cooling and curing process is performed at a temperature of 90-120° C. and a time of 1-15 seconds.
[0016] Preferably, the catalytic degreasing comprises the following specific steps: The injection blank obtained by granulation and injection molding is subjected to acid degreasing, and a gaseous nitric acid or oxalic acid with a mass percentage of 98% is used to catalyze and remove the POM binder to obtain a degreased blank; The catalytic temperature is 100-130° C. and the time is 2-8 hours.
[0017] Preferably, in the catalytic degreasing, 98% by mass of gaseous nitric acid is used for catalysis.
[0018] By adopting the above technical solution, when using 98% by mass of gaseous nitric acid for catalysis, compared with using oxalic acid for catalysis, the average density of the obtained titanium-containing high-strength lightweight steel MIM product is 6.18 g / cm 3 , and the average yield strength increased by 11.5%, the average tensile strength increased by 14.0%, and the average elongation after break increased by 57.9%. While maintaining a lower average density, it has better mechanical properties.
[0019] Technical effects of this application The present invention relates to a titanium-containing high-strength lightweight steel MIM product with an average density of 6.00-6.26 g / cm 3 , the average density is low; Furthermore, a titanium-containing high-strength lightweight steel MIM product of the present application has an average yield strength of 889.5-1040.5 MPa, an average tensile strength of 978.2-1120.5 MPa, an average elongation after break of 5.4%-10.3%, and good mechanical properties; Furthermore, the preparation method of a titanium-containing high-strength lightweight steel MIM product of the present application can accurately control the composition and amount of each raw material, thereby achieving a one-to-one correspondence between the sintering temperature and the average density, so that the obtained titanium-containing high-strength lightweight steel MIM product can achieve low-density and high-strength mechanical performance indicators. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a schematic diagram of the structure of the sample of this application; Figure 2 is a SEM image of the Fe-Mn-Al-C-Ti alloy gas atomized MIM powder in Example 1 of the present application; Figure 3 This is a stress-strain curve diagram drawn during the tensile test of the sample obtained in Example 1 of the present application, in which samples 1 to 6 are all parallel samples. DETAILED DESCRIPTION
[0021] The present application is further described in detail below with reference to the accompanying drawings and embodiments, but the present application is not limited thereto.
[0022] Except for the special raw materials listed below, all the raw materials used in the embodiments of the present application are commercially available: Fe-Mn-Al-C-Ti alloy gas atomized MIM powder was prepared by Hunan Hengji Powder Technology Co., Ltd. commissioned by Shanghai Fuchi High-Tech Co., Ltd.; Fe-Mn-Al-C alloy gas atomized MIM powder was prepared by Hunan Hengji Powder Technology Co., Ltd. commissioned by Shanghai Fuchi High-Tech Co., Ltd.
[0023] In each embodiment of the present application, the testing method of each performance parameter is as follows: Preparation of samples: The titanium-containing high-strength lightweight steel MIM product obtained in the embodiment is processed into a structure as shown in the figure Figure 1 The specimen shown is a "dumbbell" structure, with a diameter of 20 mm for the spherical structures at both ends; a rod-shaped structure is between a and b, with a diameter of 3 mm and a length of 37.4 mm; the spherical structure and the rod-shaped structure are integrally formed and connected by an arc-shaped structure with a radius of 15 mm; at least three parallel specimens are prepared for each titanium-containing high-strength lightweight steel MIM product; The above-obtained samples were subjected to average density and tensile tests under the same conditions. The specific test methods are as follows: 1. Average density test Test method: The density of the sample is measured using the method in GB / T 3850-2015 "Determination of density of dense sintered metal materials and cemented carbides". The average density of all parallel samples of the sample is taken as the average density of the titanium-containing high-strength lightweight steel MIM product. 2. Tensile test Test method: Use a universal material testing machine and adopt the method in GB / T 228.1-2021 "Metallic Material Tensile Test Part 1: Room Temperature Test Method" to carry out tensile test on the specimen at a stress rate of 1.2 mm / min. Draw a stress-strain curve during the test, and take the average value of the yield strength, tensile strength and elongation measured by parallel samples of all specimens, which is the average yield strength, average tensile strength and average elongation of the titanium-containing high-strength lightweight steel MIM product.
[0024] In the various embodiments of the present application and the test methods of various performance parameters, the names, models and manufacturers of the various equipment used are as follows: Kneading and granulating machine, model LGJ-400, produced by Nanjing Zhongbing Enso Technology Co., Ltd.; Horizontal injection molding machine, model NEX110IIIT-12E, manufactured by Nissei Plastic Industrial Co., Ltd. Vacuum debinding sintering furnace, model VM48 / 48 / 200, produced by Ningbo Hengpu Vacuum Technology Co., Ltd. Scanning electron microscope, model EVO10, produced by Carl Zeiss Optics (China) Co., Ltd.; Universal materials testing machine, model Z250SN, produced by ZwickRoell. Example 1
[0025] A titanium-containing high-strength lightweight steel MIM product, wherein the Fe-Mn-Al-C-Ti alloy gas atomized MIM powder used for its preparation, the contents of Fe, Mn, Al, C and Ti are as shown in the following table, calculated by mass percentage: content(%) Example 1 Mn 32% Al 12% C 0.9% Ti 0.5% Fe margin The powder raw material used to prepare the titanium-containing high-strength lightweight steel MIM product, namely the Fe-Mn-Al-C-Ti alloy gas atomized MIM powder, was scanned using a scanning electron microscope. The resulting SEM image is shown in FIG. Figure 2 As shown, the particle size of the Fe-Mn-Al-C-Ti alloy gas atomized MIM powder is 6.61-16.85 μm.
[0026] The above-mentioned method for preparing a titanium-containing high-strength lightweight steel MIM product comprises the following specific steps: S1. Granulation: The Fe-Mn-Al-C-Ti alloy atomized MIM powder and the plastic-based binder are poured into a kneading and granulating machine for kneading, mixing and granulation. The mixing process is controlled at a temperature of 190° C. for 2 hours to obtain particles of titanium-containing high-strength lightweight steel MIM products. The amount of the Fe-Mn-Al-C-Ti alloy atomized MIM powder and the plastic-based binder is calculated by volume ratio, and the Fe-Mn-Al-C-Ti alloy atomized MIM powder: plastic-based binder is 1:1; The above-mentioned plastic-based adhesive is a POM adhesive; S2. Injection molding: The particles of the titanium-containing high-strength lightweight steel MIM product obtained in S1 are injected into the mold by a horizontal injection molding machine. After pressure maintenance, cooling and solidification, the mold is opened and the injection blank is taken out. During the particle injection process of the titanium-containing high-strength lightweight steel MIM product, the injection temperature was controlled at 190°C and the injection speed was 60 cm 3 / s and injection pressure 90MPa; The above-mentioned holding pressure is 90MPa and the time is 6s; The above cooling and curing temperature is 110°C and the time is 8s; S3, catalytic degreasing: The injection blank is subjected to acid stripping, and 98% by mass of gaseous nitric acid is used to catalyze and remove the POM binder to obtain a degreased blank; The above catalytic temperature is 120°C and the time is 5h; S4, pre-sintering The debinded blank is pre-sintered at a temperature of 700°C for 2 hours to obtain a pre-sintered blank; S5. Sintering The pre-sintered blank was sintered for 3 h in a vacuum debinding sintering furnace under the protection of argon gas at a pressure of 0.05 MPa and a temperature of 1260° C. to obtain a sintered blank; S6, solution treatment, aging treatment and post-treatment The degreased blank obtained above is subjected to solution treatment, aging treatment and post-treatment in sequence to obtain a titanium-containing high-strength lightweight steel MIM product; The solution treatment is controlled at a temperature of 1100°C and a time of 0.5h; The aging treatment is controlled at a temperature of 490°C and a time of 4.0h; The post-treatment is to perform sandblasting, magnetic rolling and shaping on the sintered blank after the solution treatment and aging treatment.
[0027] The titanium-containing high-strength lightweight steel MIM product obtained in Example 1 above was subjected to an average density test and a tensile test, and the results are as follows: The average density of high-strength lightweight steel MIM products containing titanium is 6.18g / cm 3 ; The stress-strain curve of the tensile process of high-strength lightweight steel MIM products containing titanium is shown in the figure below: Figure 2 As shown, from Figure 3 It can be obtained that the average yield strength of the titanium-containing high-strength and lightweight steel MIM products is 1037.5MPa, the average tensile strength is 1120.5MPa, and the average elongation after fracture is 9.0%; this shows that the titanium-containing high-strength and lightweight steel MIM products have good yield strength, tensile strength and elongation after fracture while ensuring low density. Embodiment 2-5
[0028] A titanium-containing high-strength lightweight steel MIM product, which is different from Example 1 in that the Fe-Mn-Al-C-Ti alloy atomized MIM powder used for its preparation has the contents of Fe, Mn, Al, C and Ti calculated by mass percentage as shown in the following table: content(%) Example 2 Example 3 Example 4 Example 5 Mn 32% 32% 32% 32% Al 12% 12% 12% 12% C 0.9% 0.9% 0.9% 0.9% Ti 0.1% 0.2% 0.7% 1.0% Fe margin margin margin margin The specific steps of the preparation method of the above-mentioned titanium-containing high-strength lightweight steel MIM product are the same as those in Example 1. Comparative Example 1
[0029] A high-strength lightweight steel MIM product, which is different from Example 1 in that the alloy gas atomized MIM powder used in its preparation is Fe-Mn-Al-C, that is, it does not contain Ti. The contents of Fe, Mn, Al and C are shown in the following table, calculated by mass percentage: content(%) Comparative Example 1 Mn 32% Al 12% C 0.9% Fe margin The specific steps of the method for preparing the above-mentioned high-strength and lightweight steel MIM product are the same as those of the method for preparing the titanium-containing high-strength and lightweight steel MIM product in Example 1.
[0030] The titanium-containing high-strength lightweight steel MIM products obtained in Examples 2-5 and a high-strength lightweight steel MIM product (not containing titanium) obtained in Comparative Example 1 were subjected to average density test and tensile test, and compared with the test results of Example 1, as shown in the following table:
[0031] According to the data analysis in the above table, the average density of the titanium-containing high-strength lightweight steel MIM products obtained in Examples 1-5 is 6.18-6.22 g / cm 3 The average density of the high-strength lightweight steel MIM product obtained in Comparative Example 1 is 6.23 g / cm 3 , the obtained high-strength and light-weight steel MIM products maintain a relatively low average density; and the average yield strength of the high-strength and light-weight steel MIM products containing titanium obtained in Examples 1-5 is 889.5-1037.5MPa, the average tensile strength is 978.2-1120.5MPa, and the average elongation after fracture is 7.5%-10.3%. Compared with the high-strength and light-weight steel MIM products obtained in Comparative Example 1, the average yield strength is increased by 0.1%-17.2%, the average tensile strength is increased by 3.0%-17.9%, and the average elongation after fracture is increased by 17.2%-60.9%. This shows that due to the addition of titanium, the mechanical properties (average yield strength, average tensile strength and average elongation after fracture) of the obtained high-strength and light-weight steel MIM products containing titanium are improved under low density.
[0032] In particular, the titanium-containing high-strength and lightweight steel MIM products obtained in Examples 1-4 have an average yield strength of 1004.1-1037.5 MPa, an average tensile strength of 1082.3-1120.5 MPa, and an average elongation after break of 7.5%-10.3%. The average yield strength exceeds 1000 MPa, and the average elongation after break exceeds 7%. Moreover, compared with the high-strength and lightweight steel MIM products obtained in Comparative Example 1, the average yield strength is increased by 13.4%-17.2%, the average tensile strength is increased by 13.9%-17.9%, and the average elongation after break is increased by 17.2%-60.9%, and the mechanical properties are significantly improved. Embodiment 6-7
[0033] A titanium-containing high-strength lightweight steel MIM product, which is different from Example 1 in that the Fe-Mn-Al-C-Ti alloy atomized MIM powder used for its preparation has the contents of Fe, Mn, Al, C and Ti calculated by mass percentage as shown in the following table: content(%) Example 6 Example 7 Mn 31% 33% Al 13% 11% C 1.2% 0.8% Ti 0.1% 1.0% Fe margin margin The specific steps of the preparation method of the above-mentioned titanium-containing high-strength lightweight steel MIM product are the same as those in Example 1.
[0034] The titanium-containing high-strength lightweight steel MIM products obtained in Examples 6-7 above were subjected to average density test and tensile test, and the test results are shown in the following table:
[0035] From the analysis of the data in the above table, it can be seen that the average density of the titanium-containing high-strength lightweight steel MIM products obtained in Examples 6-7 is 6.19-6.20 g / cm 3 , the average yield strength is 890.2-898.6MPa, the average tensile strength is 982.3-986.1MPa, and the average break rate is 5.4%-5.6%. Example 8
[0036] A titanium-containing high-strength lightweight steel MIM product, wherein the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder used for its preparation has the same contents of Fe, Mn, Al, C and Ti as those used for the preparation of the titanium-containing high-strength lightweight steel MIM product in Example 1, calculated by mass percentage.
[0037] The above-mentioned method for preparing a titanium-containing high-strength lightweight steel MIM product is different from the method for preparing a titanium-containing high-strength lightweight steel MIM product in Example 1 in that: In step S4, during the sintering process, the pre-sintered blank is sintered for 3 hours in a vacuum debinding sintering furnace under the protection of argon gas at a controlled pressure of 0.05 MPa and a controlled temperature of 1250° C. to obtain a sintered blank. Example 9
[0038] A titanium-containing high-strength lightweight steel MIM product, wherein the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder used for its preparation has the same contents of Fe, Mn, Al, C and Ti as those used for the preparation of the titanium-containing high-strength lightweight steel MIM product in Example 1, calculated by mass percentage.
[0039] The above-mentioned method for preparing a titanium-containing high-strength lightweight steel MIM product is different from the method for preparing a titanium-containing high-strength lightweight steel MIM product in Example 1 in that: In step S4, during the sintering process, the pre-sintered blank is sintered for 3 hours in a vacuum debinding sintering furnace under the protection of argon gas at a controlled pressure of 0.05 MPa and a controlled temperature of 1255° C. to obtain a sintered blank. Example 10
[0040] A titanium-containing high-strength lightweight steel MIM product, wherein the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder used for its preparation has the same contents of Fe, Mn, Al, C and Ti as those used for the preparation of the titanium-containing high-strength lightweight steel MIM product in Example 1, calculated by mass percentage.
[0041] The above-mentioned method for preparing a titanium-containing high-strength lightweight steel MIM product is different from the method for preparing a titanium-containing high-strength lightweight steel MIM product in Example 1 in that: In step S4, during the sintering process, the pre-sintered blank is sintered for 3 hours in a vacuum debinding sintering furnace under the protection of argon gas at a controlled pressure of 0.05 MPa and a controlled temperature of 1265° C. to obtain a sintered blank. Embodiment 11
[0042] A titanium-containing high-strength lightweight steel MIM product, wherein the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder used for its preparation has the same contents of Fe, Mn, Al, C and Ti as those used for the preparation of the titanium-containing high-strength lightweight steel MIM product in Example 1, calculated by mass percentage.
[0043] The above-mentioned method for preparing a titanium-containing high-strength lightweight steel MIM product is different from the method for preparing a titanium-containing high-strength lightweight steel MIM product in Example 1 in that: In step S4, during the sintering process, the pre-sintered blank is sintered for 3 hours in a vacuum debinding sintering furnace under the protection of argon gas at a controlled pressure of 0.05 MPa and a controlled temperature of 1270° C. to obtain a sintered blank.
[0044] The average density test was performed on the titanium-containing high-strength lightweight steel MIM products obtained in the above Examples 8-11, and compared with the average density test results of Example 1, as shown in the following table: <![CDATA[Average density (g / cm 3 ).]]> Example 1 6.18 Example 8 6.00 Example 9 6.12 Example 10 6.23 Embodiment 11 6.26 Through the analysis of the data in the above table, it can be concluded that the average density of the titanium-containing high-strength and lightweight steel MIM products obtained in Examples 8-11 corresponds to the sintering temperature one by one; this shows that when other conditions are the same, the sintering temperature is the key factor affecting the average density of the titanium-containing high-strength and lightweight steel MIM products. Therefore, by adopting this preparation method, the composition and content of each raw material can be accurately controlled, so as to achieve a one-to-one correspondence between the sintering temperature and the average density, so that the obtained titanium-containing high-strength and lightweight steel MIM products can achieve the performance indicators of low density and high strength. Example 12
[0045] A titanium-containing high-strength lightweight steel MIM product, wherein the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder used for its preparation has the same contents of Fe, Mn, Al, C and Ti as those used for the preparation of the titanium-containing high-strength lightweight steel MIM product in Example 1, calculated by mass percentage.
[0046] The above-mentioned method for preparing a titanium-containing high-strength lightweight steel MIM product is different from the method for preparing a titanium-containing high-strength lightweight steel MIM product in Example 1 in that: In the granulation step S1, the amount of the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder and the plastic-based binder is calculated by volume ratio, and the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder: plastic-based binder is 1:0.6. Embodiment 13
[0047] A titanium-containing high-strength lightweight steel MIM product, wherein the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder used for its preparation has the same contents of Fe, Mn, Al, C and Ti as those used for the preparation of the titanium-containing high-strength lightweight steel MIM product in Example 1, calculated by mass percentage.
[0048] The above-mentioned method for preparing a titanium-containing high-strength lightweight steel MIM product is different from the method for preparing a titanium-containing high-strength lightweight steel MIM product in Example 1 in that: In the granulation step S1, the amount of the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder and the plastic-based binder is calculated by volume ratio, and the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder: plastic-based binder is 1:0.4.
[0049] The titanium-containing high-strength lightweight steel MIM products obtained in Examples 12-13 above were subjected to average density test and tensile test, and the test results are shown in the following table: From the analysis of the data in the above table, it can be seen that the average density of the titanium-containing high-strength lightweight steel MIM products obtained in Examples 12-13 is 6.18 g / cm 3 , the average yield strength is 1020.8-1026.1MPa, the average tensile strength is 1113.7-1116.2MPa, and the average break rate is 8.4%-8.6%. Embodiment 14
[0050] A titanium-containing high-strength lightweight steel MIM product, wherein the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder used for its preparation has the same contents of Fe, Mn, Al, C and Ti as those used for the preparation of the titanium-containing high-strength lightweight steel MIM product in Example 1, calculated by mass percentage.
[0051] The above-mentioned method for preparing a titanium-containing high-strength lightweight steel MIM product is different from the method for preparing a titanium-containing high-strength lightweight steel MIM product in Example 1 in that: In step S3, catalytic degreasing is performed using oxalic acid.
[0052] The titanium-containing high-strength lightweight steel MIM product obtained in Example 14 was subjected to an average density test and a tensile test. The test results are shown in the following table:
[0053] From the data analysis in the above table, it can be concluded that the average density of the titanium-containing high-strength lightweight steel MIM product obtained by catalysis with oxalic acid is 6.19 g / cm 3 , the average yield strength is 930.2MPa, the average tensile strength is 982.8MPa, and the average elongation after break is 5.7%. Embodiment 15
[0054] A titanium-containing high-strength lightweight steel MIM product, wherein the Fe-Mn-Al-C-Ti alloy aerosolized MIM powder used for its preparation has the same contents of Fe, Mn, Al, C and Ti as those used for the preparation of the titanium-containing high-strength lightweight steel MIM product in Example 1, calculated by mass percentage.
[0055] The above-mentioned method for preparing a titanium-containing high-strength lightweight steel MIM product comprises the following specific steps: S1. Granulation: The Fe-Mn-Al-C-Ti alloy atomized MIM powder and the plastic-based binder are poured into a kneading and granulating machine for kneading, mixing and granulation. The mixing process is controlled at a temperature of 185° C. for 3 hours to obtain particles of titanium-containing high-strength lightweight steel MIM products. The amount of the Fe-Mn-Al-C-Ti alloy atomized MIM powder and the plastic-based binder is calculated by volume ratio, and the Fe-Mn-Al-C-Ti alloy atomized MIM powder: plastic-based binder is 1:1; The above-mentioned plastic-based adhesive is a POM adhesive; S2. Injection molding: The particles of the titanium-containing high-strength lightweight steel MIM product obtained in S1 are injected into the mold by a horizontal injection molding machine. After pressure maintenance, cooling and solidification, the mold is opened and the injection blank is taken out; During the particle injection process of the titanium-containing high-strength lightweight steel MIM product, the injection temperature was controlled at 170°C and the injection speed was controlled at 35 cm 3 / s and injection pressure 60MPa; The above-mentioned holding pressure is 60MPa and the time is 10s; The above cooling and curing temperature is 120°C and the time is 15s; S3, catalytic degreasing: The injection blank is subjected to acid stripping, and 98% by mass of gaseous nitric acid is used to catalyze and remove the POM binder to obtain a degreased blank; The above catalytic temperature is 100°C and the time is 8h; S4, pre-sintering The debinded blank was pre-sintered at a temperature of 500°C for 3 hours to obtain a pre-sintered blank; S5. Sintering The pre-sintered blank was sintered for 3 h in a vacuum debinding sintering furnace under the protection of argon gas at a pressure of 0.05 MPa and a temperature of 1250° C. to obtain a sintered blank; S6, solution treatment, aging treatment and post-treatment The degreased blank obtained above is subjected to solution treatment, aging treatment and post-treatment in sequence to obtain a titanium-containing high-strength lightweight steel MIM product; The solution treatment is controlled at a temperature of 1075°C and a time of 1.0h; The aging treatment is controlled at a temperature of 550°C and a time of 0.5h; The post-treatment is to perform sandblasting, magnetic rolling and shaping on the sintered blank after the solution treatment and aging treatment. Example 16
[0056] A titanium-containing high-strength lightweight steel MIM product, wherein the Fe-Mn-Al-C-Ti alloy atomized MIM powder used in its preparation has the same composition and content of each raw material used in its preparation as the titanium-containing high-strength lightweight steel MIM product of Example 1, calculated by mass percentage. The preparation method of the above-mentioned titanium-containing high-strength lightweight steel MIM product comprises the following specific steps: S1. Granulation: The Fe-Mn-Al-C-Ti alloy aerosolized MIM powder and the plastic-based binder are poured into a kneading and granulating machine for kneading, mixing and granulation. The mixing process is controlled at a temperature of 195°C for 1 hour to obtain particles of titanium-containing high-strength lightweight steel MIM products; The amount of the Fe-Mn-Al-C-Ti alloy atomized MIM powder and the plastic-based binder is calculated by volume ratio, and the Fe-Mn-Al-C-Ti alloy atomized MIM powder: plastic-based binder is 1:1; The above-mentioned plastic-based adhesive is a POM adhesive; S2. Injection molding: The particles of the titanium-containing high-strength lightweight steel MIM product obtained in S1 are injected into the mold by a horizontal injection molding machine. After pressure maintenance, cooling and solidification, the mold is opened and the injection blank is taken out; During the particle injection process of the above-mentioned titanium-containing high-strength lightweight steel MIM product, the injection temperature was controlled at 210°C and the injection speed was 85 cm 3 / s and injection pressure 120MPa; The above-mentioned holding pressure is 120MPa and the time is 2s; The above cooling and curing temperature is 90°C and the time is 1s; S3, catalytic degreasing: The injection blank is subjected to acid stripping, and 98% by mass of gaseous nitric acid is used to catalyze and remove the POM binder to obtain a degreased blank; The above catalytic temperature is 130°C and the time is 2h; S4, pre-sintering The debinded blank was pre-sintered at a temperature of 900°C for 1 hour to obtain a pre-sintered blank; S5. Sintering The pre-sintered blank was sintered for 1 hour in a vacuum debinding sintering furnace under the protection of argon gas at a pressure of 0.05 MPa and a temperature of 1270° C. to obtain a sintered blank; S6, solution treatment, aging treatment and post-treatment The degreased blank obtained above is subjected to solution treatment, aging treatment and post-treatment in sequence to obtain a titanium-containing high-strength lightweight steel MIM product; The solution treatment is carried out at a controlled temperature of 1050°C and a time of 1.5 hours; The aging treatment is controlled at a temperature of 470°C and a time of 6.0h; The post-treatment is to perform sandblasting, magnetic rolling and shaping on the sintered blank after the solution treatment and aging treatment.
[0057] The titanium-containing high-strength lightweight steel MIM products obtained in Examples 15-16 above were subjected to average density test and tensile test, and the test results are shown in the following table: According to the data analysis in the above table, the average density of the titanium-containing high-strength lightweight steel MIM products obtained in Examples 15-16 is 6.19 g / cm 3, the average yield strength is 1021.6-1040.5MPa, the average tensile strength is 1056.6-1070.9MPa, and the average elongation after break is 5.4%-5.8%.
[0058] The specific embodiments of the present application are merely explanations of the present application and are not limitations of the present application. After reading this specification, those skilled in the art may make modifications to the embodiments without any creative contribution as needed. However, as long as they are within the scope of the claims of the present application, they are protected by the patent law.
Claims
1. A titanium-containing high-strength lightweight steel MIM product, characterized in that: The powder raw material used in its preparation is Fe-Mn-Al-C-Ti alloy gas atomized MIM powder; The Fe-Mn-Al-C-Ti alloy gas atomized MIM powder, calculated by mass percentage, has the following contents of Fe, Mn, Al, C and Ti: Mn31-33% Al11-13% C0.8-1.2% Ti0.1-1.0% The balance is Fe; The D50 of the Fe-Mn-Al-C-Ti alloy gas atomized MIM powder is 5-20 μm.
2. A titanium-containing high-strength lightweight steel MIM product as claimed in claim 1, characterized in that: The Fe-Mn-Al-C-Ti alloy gas atomized MIM powder used for its preparation has the following contents of Fe, Mn, Al, C and Ti calculated by mass percentage: Mn31-33% Al11-13% C0.8-1.2% Ti0.1%-0.7% The balance is Fe; The D50 of the Fe-Mn-Al-C-Ti alloy gas atomized MIM powder is 5-20 μm.
3. A titanium-containing high-strength lightweight steel MIM product as claimed in claim 2, characterized in that: The Fe-Mn-Al-C-Ti alloy gas atomized MIM powder used for its preparation has the following contents of Fe, Mn, Al, C and Ti calculated by mass percentage: Mn32% Al12% C0.9% Ti0.1%-0.7% The balance is Fe; The D50 of the Fe-Mn-Al-C-Ti alloy gas atomized MIM powder is 5-20 μm.
4. A titanium-containing high-strength lightweight steel MIM product as claimed in claim 3, characterized in that: The Fe-Mn-Al-C-Ti alloy gas atomized MIM powder used for its preparation has the following contents of Fe, Mn, Al, C and Ti calculated by mass percentage: Mn32% Al12% C0.9% Ti0.5% The balance is Fe; The D50 of the Fe-Mn-Al-C-Ti alloy gas atomized MIM powder is 5-20 μm.
5. A titanium-containing high-strength lightweight steel MIM product as claimed in claim 1, characterized in that: The Fe-Mn-Al-C-Ti alloy gas atomized MIM powder used in its preparation was commissioned to Hunan Hengji Powder Technology Co., Ltd.
6. The method for preparing a titanium-containing high-strength lightweight steel MIM product according to any one of claims 1 to 5, characterized in that: The specific steps include: The Fe-Mn-Al-C-Ti alloy gas atomized MIM powder is sequentially granulated, injection molded and catalytically degreased, and the degreased blank is then sequentially pre-sintered, sintered, solution treated and aged to obtain a titanium-containing high-strength lightweight steel MIM product; In the pre-sintering process, the debinded blank is pre-sintered at a temperature of 500-900° C. for 1-3 hours to obtain a pre-sintered blank; In the sintering process, the pre-sintered blank is sintered for 1-3 hours under the protection of an inert gas at a temperature of 1250-1270° C. to obtain a sintered blank; the inert gas is argon; The solution treatment is controlled at a temperature of 1050-1100°C and a time of 0.5-1.5h; The aging treatment is carried out at a controlled temperature of 470-550°C and a time of 0.5-6.0h.
7. The method for preparing a titanium-containing high-strength lightweight steel MIM product according to claim 6, characterized in that: The granulation process comprises the following specific steps: The Fe-Mn-Al-C-Ti alloy atomized MIM powder is kneaded, mixed and granulated with a plastic-based binder, and the mixing process temperature is controlled at 185-195°C to obtain particles of a titanium-containing high-strength lightweight steel MIM product; The amount of the Fe-Mn-Al-C-Ti alloy atomized MIM powder and the plastic-based binder is calculated by volume ratio, Fe-Mn-Al-C-Ti alloy atomized MIM powder: plastic-based binder is 1:0.4-1; The plastic-based adhesive is a POM adhesive.
8. The method for preparing a titanium-containing high-strength lightweight steel MIM product according to claim 7, characterized in that: The injection molding process comprises the following specific steps: The particles of the titanium-containing high-strength lightweight steel MIM product obtained by the granulation are injected into a mold, and after pressure maintenance, cooling and solidification, the mold is opened to take out the injection blank; During the particle injection process of the titanium-containing high-strength lightweight steel MIM product, the injection temperature is controlled at 170-210°C and the injection speed is controlled at 35-85cm 3 / s and injection pressure 60-120MPa; The holding pressure is 60-120 MPa and the holding time is 2-10 s; The cooling and curing process is performed at a temperature of 90-120° C. and a time of 1-15 seconds.
9. The method for preparing a titanium-containing high-strength lightweight steel MIM product according to claim 8, characterized in that: The catalytic degreasing comprises the following specific steps: The injection blank obtained by granulation and injection molding is subjected to acid degreasing, and 98% by mass gaseous nitric acid or oxalic acid is used to catalyze and remove the POM binder to obtain a degreased blank; The catalytic temperature is 100-130° C. and the time is 2-8 hours.
10. The method for preparing a titanium-containing high-strength lightweight steel MIM product according to claim 9, characterized in that: In the catalytic degreasing, 98% by mass of gaseous nitric acid is used for catalysis.