阅读说明：本技术 一种钛钼中间合金短流程低成本制备方法 (Short-flow low-cost preparation method of titanium-molybdenum intermediate alloy ) 是由 乔敏 赵超 金环 张娟 王建东 孙雪梅 王文红 于 2021-09-03 设计创作，主要内容包括：本发明公开一种钛钼中间合金短流程低成本制备方法。该方法包括：将原料Ti粉、MoO-(3)粉和Mg粉进行干燥、混匀,将混合物料在常温下装入刚玉坩埚中,再整体放置于拆除掉熔炼系统的真空炉中,对真空炉进行抽真空处理,真空度达到5Pa后充氩气至炉内为一个大气压的状态,采用金属热还原冶炼法进行合金冶炼,得到化学成分完全符合钛合金技术要求的钛钼中间合金。本发明所提供的钛钼中间合金制备方法生产工艺简单、生产周期较短、生产成本较低,适合于规模化工业生产。(The invention discloses a short-process low-cost preparation method of a titanium-molybdenum intermediate alloy. The method comprises the following steps: mixing raw materials of Ti powder and MoO 3 Drying and uniformly mixing the powder and Mg powder, putting the mixed material into a corundum crucible at normal temperature, integrally placing the corundum crucible into a vacuum furnace with a removed smelting system, vacuumizing the vacuum furnace, filling argon into the furnace to be in a state of one atmospheric pressure after the vacuum degree reaches 5Pa, and smelting the alloy by adopting a metallothermic reduction smelting method to obtain the titanium-molybdenum intermediate alloy with chemical components completely meeting the technical requirements of titanium alloy. The preparation method of the titanium-molybdenum intermediate alloy provided by the invention has the advantages of simple production process, short production period and low production cost, and is suitable for large-scale industrial production.)

1. The titanium-molybdenum intermediate alloy is characterized by comprising the following raw materials in parts by weight: 100 parts of Ti powder, MoO₃58-96 parts of powder and 3-5 parts of Mg powder.

2. The titanium molybdenum intermediate alloy as recited in claim 1, wherein the purity of the Ti powder is not less than 99.5%; the MoO₃The purity of the powder is more than or equal to 99.9 percent; the purity of the Mg powder is more than or equal to 99.9 percent.

3. The titanium molybdenum master alloy of claim 1, wherein the Ti powder, MoO₃The particle sizes of the powder and the Mg powder are both less than or equal to 3 mm.

4. A method for preparing a titanium molybdenum master alloy according to any one of claims 1 to 3, comprising the steps of:

mixing Ti powder and MoO₃And respectively drying and mixing the powder and the Mg powder to obtain a mixed material, and smelting the alloy by adopting a furnace metallothermic reduction smelting method in a vacuum environment to obtain the titanium-molybdenum intermediate alloy.

5. The method as claimed in claim 4, wherein the drying temperature is 100 ℃ and 130 ℃ and the drying time is 6-12 h.

6. The method according to claim 4, wherein the vacuum atmosphere is a state where a protective gas is filled to a normal atmospheric pressure at a vacuum degree of 5 Pa.

7. The method of claim 6, wherein the shielding gas is argon.

8. The method according to claim 4, wherein the alloy is smelted at 2400 ℃ for 1.5 min.

Technical Field

The invention belongs to the technical field of metal material processing, and particularly relates to a short-flow low-cost preparation method of a titanium-molybdenum intermediate alloy.

Background

Titanium molybdenum master alloy (Mo: 30-50%) is an important titanium alloy raw material, and is commonly used for titanium alloy grades containing only Mo and no Al, such as TB7 (nominal composition Ti-32Mo), TB11 (nominal composition Ti-15Mo), or high Mo and low Al titanium alloy grades, such as TB8 (nominal composition Ti-15Mo-3Al-2.7Nb-0.25 Si).

The production method of the intermediate alloy for titanium alloy generally adopts an aluminothermic reduction method or a vacuum induction melting method. If an aluminothermic reduction method is adopted, a certain amount of impurity aluminum (Al is more than or equal to 0.5%) is inevitably remained in the titanium-molybdenum master alloy on the premise of ensuring that the content of impurity oxygen in the titanium-molybdenum master alloy meets the technical requirement (O is less than or equal to 0.3%); on the premise of ensuring that the content of impurity aluminum in the titanium-molybdenum intermediate alloy meets the technical requirement (Al is less than or equal to 0.1 percent), the content of impurity oxygen in the alloy is higher (O is more than or equal to 0.8 percent). Neither case can meet the technical requirements of the titanium molybdenum intermediate alloy. If the vacuum induction melting method is adopted, the melting point of the common titanium-molybdenum intermediate alloy is very high (more than or equal to 1800 ℃), and a common vacuum induction furnace is limited by equipment and a melting crucible and cannot meet the requirement of high-temperature long-time melting, so that the vacuum induction melting method cannot be adopted to produce the titanium-molybdenum intermediate alloy.

The titanium molybdenum intermediate alloy can be prepared by adopting a VAR (vacuum consumable arc melting) or powder sintering mode, but the two preparation methods have the problems of complex process, longer production period and higher cost.

Disclosure of Invention

In view of the above, the invention aims to provide a short-flow low-cost preparation method of a titanium molybdenum intermediate alloy, wherein the prepared titanium molybdenum intermediate alloy can meet the use technical requirements of titanium alloys, and has the advantages of simple process, short production period and low cost.

In order to achieve the technical purpose, the invention provides the following technical scheme:

the titanium-molybdenum intermediate alloy comprises the following components in parts by weightMaterial preparation: 100 parts of Ti powder, MoO₃58-96 parts of powder and 3-5 parts of Mg powder.

Preferably, the purity of the Ti powder is more than or equal to 99.5 percent; the MoO₃The purity of the powder is more than or equal to 99.9 percent; the purity of the Mg powder is more than or equal to 99.9 percent. The adoption of the raw material with the purity is beneficial to the stable operation of the metal thermal reduction smelting in the furnace and the preparation of the titanium-molybdenum intermediate alloy with low impurity content and good component uniformity.

Preferably, the Ti powder and MoO₃The particle sizes of the powder and the Mg powder are both less than or equal to 3 mm. The adoption of the raw materials with the particle sizes is beneficial to uniformly mixing the raw materials, and the problem of segregation of components of the titanium-molybdenum intermediate alloy caused by nonuniform raw material mixing is avoided.

The invention also provides a preparation method of the titanium-molybdenum intermediate alloy, which comprises the following steps:

mixing Ti powder and MoO₃And respectively drying and mixing the powder and the Mg powder to obtain a mixed material, putting the mixed material into a corundum crucible at normal temperature, integrally placing the corundum crucible into a vacuum furnace with a melting system removed, and smelting the alloy by adopting a metallothermic reduction smelting method in the furnace to obtain the titanium-molybdenum intermediate alloy.

Preferably, the drying temperature is 100-130 ℃, more preferably 110-120 ℃; the drying time is 6-12h, more preferably 8-10 h. The drying can remove the moisture in the raw materials and prevent serious splashing in the metal thermal reduction smelting process.

Preferably, the vacuum furnace is filled with a protective gas to a standard atmospheric pressure at a vacuum degree of 5 Pa.

Preferably, the protective gas is argon. The protective gas can effectively avoid the increase of the gas impurity content of the titanium-molybdenum intermediate alloy caused by the contact of air and the generated titanium-molybdenum intermediate alloy in the metal thermal reduction smelting process.

Preferably, the temperature for smelting the alloy is 2400 ℃ and the time is 1.5 min.

Compared with the prior art, the invention has the beneficial effects that:

the invention respectively uses Ti powder and Mg powder and MoO₃Performing replacement reaction on the powder to obtain a replacement product Mo, Mo and excessive MoThe Ti powder is combined to prepare the required titanium-molybdenum intermediate alloy. Ti powder and MoO₃The unit heat release of the powder for replacement reaction is 2232.8kcal/kg, and the Mg powder and MoO₃The unit exotherm for the powder displacement reaction was 3472.5 kcal/kg. It can be seen that Mg powder and MoO₃The unit heat of the powder for replacement reaction is higher, and the unit heat can be used for adjusting the heat of the metallothermic reduction reaction. The handbook of chemistry, lanche shows: MgO, TiO₂And MoO₃The standard Gibbs free energy of the formed oxides is-1138.6 kJ/mol, -888.8kJ/mol and-445.4 kJ/mol respectively, the gradient difference of the Gibbs free energy of the three oxides along with the change of the temperature is small, which shows that the thermal stability of MgO is the highest and the MgO is similar to that of MoO₃The Gibbs free energy difference is large, and the condition that unreacted Mg powder is remained in the titanium-molybdenum intermediate alloy can not occur. Respectively mixing Ti powder and Mg powder with MoO₃By-products TiO, TiO generated after powder is subjected to displacement reaction₂And MgO is not compact enough, so that the generated titanium molybdenum intermediate alloy cannot be effectively protected, and the reaction is carried out in a protective gas state in the furnace, so that the increase of the gas impurity content of the generated titanium molybdenum intermediate alloy can be effectively prevented. Compared with the existing preparation method of the titanium-molybdenum intermediate alloy, the preparation method adopted by the invention has the advantages of simple production process, shorter production period and lower production cost, and is suitable for large-scale industrial production. Experimental results show that the titanium-molybdenum intermediate alloy prepared by the method has the main element Mo content of 30-50%, impurity Fe content of less than or equal to 0.12%, impurity Si content of less than or equal to 0.05%, impurity Al content of less than or equal to 0.03%, impurity Mg content of less than or equal to 0.001%, impurity C content of less than or equal to 0.01%, impurity O content of less than or equal to 0.06%, and impurity N content of less than or equal to 0.01%, and can completely meet the technical requirements of the titanium-molybdenum intermediate alloy for titanium alloy.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The specification and examples are exemplary only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

The Ti powder comprises the following main components: more than or equal to 99.5 percent of Ti, less than or equal to 0.12 percent of Fe, less than or equal to 0.03 percent of Si, less than or equal to 0.02 percent of Al and less than or equal to 0.03 percent of C.

MoO₃The powder comprises the following main components: MoO₃≥99.9％，Fe≤0.01％，Si≤0.01％，Al≤0.02％，C≤0.02％。

The Mg powder comprises the following main components: more than or equal to 99.9 percent of Mg, less than or equal to 0.01 percent of Fe, less than or equal to 0.01 percent of Si, less than or equal to 0.02 percent of Al and less than or equal to 0.02 percent of C.

Ti powder, MoO₃The particle sizes of the powder and the Mg powder are both less than or equal to 3 mm.

Examples 1 to 9

(1) Weighing Ti powder and MoO₃The powder and Mg powder are under the conditions of 100 ℃ and 130 DEG CDrying for 6-12h, and mixing to obtain a mixed material;

(2) and (2) putting the mixed material into a corundum crucible at normal temperature, integrally placing the corundum crucible into a vacuum furnace with a removed smelting system, vacuumizing the vacuum furnace, filling argon into the furnace to be in a state of one atmospheric pressure after the vacuum degree reaches 5Pa, and smelting the alloy by adopting a metallothermic reduction smelting method at the temperature of 2400 ℃ for 1.5min to obtain the titanium-molybdenum intermediate alloy.

The metallothermic reduction reaction related to the titanium-molybdenum intermediate alloy mainly comprises Ti powder and MoO₃Powder, Mg powder and MoO₃Displacement reaction of the powders was carried out separately. The handbook of chemistry, lanche shows: MoO₃、TiO₂And the delta H of MgO is-745.2 kJ/mol, -944.0kJ/mol and-601.6 kJ/mol respectively, so that the Ti powder and the MoO₃The powder was subjected to the displacement reaction:

47.87g 95.96g＝63.96g 79.87g

0kJ -496.8kJ＝0kJ -944.0kJ -447.2kJ

the unit exotherm for this reaction is:

447.2kJ/(4.184kJ/kcal×47.87×10^-3kg)＝2232.8kcal/kg。

mg powder and MoO₃The powder was subjected to the displacement reaction:

24.31g 47.98g＝31.98g 40.31g

0kJ -248.4kJ＝0kJ -601.6kJ -353.2kJ

the unit exotherm for this reaction is:

353.2kJ/(4.184kJ/kcal×24.31×10^-3kg)＝3472.5kcal/kg。

examples 1-9 titanium molybdenum master alloys were prepared according to the parameters of table 1.

TABLE 1 preparation parameters of titanium molybdenum master alloys of examples 1-9 of the present invention

Preparation parameters	Drying temperature	Drying time	Raw material ratio
				Example 1	100℃	12h	100 parts of Ti powder and 58 parts of MoO3Powder, 5 parts of Mg powder
Example 2	130℃	6h	100 parts of Ti powder and 96 parts of MoO3Powder, 3 parts of Mg powder
				Example 3	115℃	9h	100 parts of Ti powder and 77 parts of MoO3Powder, 4 parts of Mg powder
Example 4	110℃	8h	100 parts of Ti powder and 58 parts of MoO3Powder, 3 parts of Mg powder
				Example 5	120℃	10h	100 parts of Ti powder and 96 parts of MoO3Powder, 5 parts of Mg powder
Example 6	110℃	11h	100 parts of Ti powder and 67 parts of MoO3Powder, 5 parts of Mg powder
				Example 7	130℃	8h	100 parts of Ti powder and 87 parts of MoO3Powder, 3 parts of Mg powder
Example 8	120℃	10h	100 parts of Ti powder and 67 parts of MoO3Powder, 3 parts of Mg powder
				Example 9	100℃	11h	100 parts of Ti powder and 87 parts of MoO3Powder, 5 parts of Mg powder

Note: the "parts" in table 1 are parts by mass.

The titanium molybdenum master alloys prepared in examples 1 to 9 were subjected to chemical composition analysis, and the results are shown in table 2.

Table 2 titanium molybdenum master alloy chemistry/wt% according to invention examples 1-9

Alloy composition	Mo	Fe	Si	Al	Mg	C	O	N	Ti
										Example 1	30	0.12	0.05	0.02	≤0.001	0.01	0.06	0.01	Balance of
Example 2	50	0.09	0.05	0.02	≤0.001	0.01	0.03	0.01	Balance of
										Example 3	40	0.10	0.04	0.03	≤0.001	0.01	0.04	0.01	Balance of
Example 4	32	0.11	0.05	0.02	≤0.001	0.01	0.05	0.01	Balance of
										Example 5	47	0.09	0.04	0.02	≤0.001	0.01	0.04	0.01	Balance of
Example 6	33	0.11	0.05	0.02	≤0.001	0.01	0.04	0.01	Balance of
										Example 7	43	0.12	0.05	0.02	≤0.001	0.01	0.04	0.01	Balance of
Example 8	35	0.10	0.04	0.03	≤0.001	0.01	0.05	0.01	Balance of
										Example 9	42	0.11	0.04	0.02	≤0.001	0.01	0.05	0.01	Balance of

As can be seen from Table 2, the titanium molybdenum master alloy prepared by the preparation method of the invention has stable components and low impurity content.

The titanium molybdenum intermediate alloy prepared in the embodiment 1 to 9 is applied to titanium alloy, and completely meets the technical requirements of the titanium alloy.

Comparative examples 1 to 3

The difference from example 1 is that the raw material formulation is shown in Table 3.

TABLE 3 comparative examples 1-3 titanium molybdenum master alloy preparation parameters

Preparation parameters	Drying temperature	Drying time	Raw material ratio
				Comparative example 1	100℃	12h	110 parts of Ti powder and 58 parts of MoO3Powder, 5 parts of Mg powder
Comparative example 2	100℃	12h	100 parts of Ti powder and 50 parts of MoO3Powder, 5 parts of Mg powder
				Comparative example 3	100℃	12h	100 parts of Ti powder and 58 parts of MoO3Powder, 10 parts of Mg powder

Note: the "parts" in table 3 are parts by mass.

The titanium molybdenum master alloys prepared in comparative examples 1 to 3 were subjected to chemical composition analysis, and the results are shown in table 4.

Table 4 comparative examples 1-3 titanium molybdenum master alloy chemical composition/wt. -%)

Alloy composition	Mo	Fe	Si	Al	Mg	C	O	N	Ti
										Comparative example 1	28	0.12	0.05	0.02	≤0.001	0.01	0.05	0.01	Balance of
Comparative example 2	27	0.11	0.04	0.02	≤0.001	0.01	0.05	0.01	Balance of
										Comparative example 3	27	0.12	0.05	0.02	≤0.001	0.01	0.06	0.01	Balance of

As can be seen from Table 4, the main element Mo of the titanium-molybdenum intermediate alloy which is not prepared according to the dosage relationship defined by the invention is less than or equal to 28 percent, which does not meet the technical requirement that the main element Mo of the titanium-molybdenum intermediate alloy is more than or equal to 30 percent of the titanium alloy.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included therein.