阅读说明：本技术 一种热挤压成型钛合金管材用润滑剂及其制备方法和应用 (Lubricant for hot extrusion molding of titanium alloy pipe and preparation method and application thereof ) 是由 肖强 刘振军 吴东辉 王本京 高龙 张洋 于 2020-12-09 设计创作，主要内容包括：一种热挤压成型钛合金管材用润滑剂及其制备方法和应用。本发明属于润滑剂及其制备领域。本发明为解决现有玻璃润滑剂在挤压润滑过程中流动性不好、易于起皮开裂的技术问题。本发明的一种热挤压成型钛合金管材用润滑剂按质量份数由35～45份SiO-2、2～4份Al-2O-3、18～28份B-2O-3、17～21份Na-2O、5～8份CaO、1～5份MgO、1～8份BaO、1～5份ZnO和1～2份LiO制备而成。制备方法：一、按配方将物料混合均匀,然后进行加热熔炼,得到玻璃液；二、倒入冷水中冷淬,干燥后球磨,烘干后过筛,得到润滑剂。作为热挤压成型钛合金管材用润滑剂的应用。涂覆了本发明润滑剂涂层的TC4钛合金挤压后管材表面整体光滑,没有明显的纵向和横向的划痕等其它缺陷,整体表面质量优于传统工艺润滑剂挤压的管材表面质量。(A lubricant for hot extrusion molding titanium alloy pipes and a preparation method and application thereof. The invention belongs to a lubricant and a lubricant thereofThe field of preparation. The invention aims to solve the technical problems that the existing glass lubricant has poor fluidity and is easy to peel and crack in the extrusion lubrication process. The lubricant for the hot extrusion molding titanium alloy pipe comprises 35-45 parts by mass of SiO 2 2-4 parts of Al 2 O 3 18 to 28 parts of B 2 O 3 17 to 21 parts of Na 2 O, 5-8 parts of CaO, 1-5 parts of MgO, 1-8 parts of BaO, 1-5 parts of ZnO and 1-2 parts of LiO. The preparation method comprises the following steps: firstly, uniformly mixing materials according to a formula, and then heating and smelting to obtain molten glass; and secondly, pouring the mixture into cold water for cold quenching, drying, ball-milling, drying and sieving to obtain the lubricant. The lubricant is applied to hot extrusion forming of titanium alloy pipes. The TC4 titanium alloy coated with the lubricant coating of the invention has smooth surface of the extruded pipe, has no obvious longitudinal and transverse scratches and other defects, and has better surface quality than the pipe extruded by the lubricant in the traditional process.)

1. The lubricant for the hot extrusion molding titanium alloy pipe is characterized by comprising 35-45 parts by mass of SiO₂2-4 parts of Al₂O₃18 to 28 parts of B₂O₃17 to 21 parts of Na₂O, 5-8 parts of CaO, 1-5 parts of MgO, 1-8 parts of BaO, 1-5 parts of ZnO and 1-2 parts of LiO.

2. The method for preparing the lubricant for the hot extrusion forming of the titanium alloy pipe as claimed in claim 1, wherein the preparation method comprises the following steps:

firstly, SiO₂、Al₂O₃、B₂O₃、Na₂Mixing O, CaO, MgO, BaO, ZnO and LiO uniformly, and then heating and smelting to obtain molten glass;

and secondly, pouring the glass liquid into cold water, performing cold quenching to obtain glass particles, drying, adding absolute ethyl alcohol, performing ball milling to obtain glass powder, drying, and sieving to obtain the lubricant.

3. The preparation method of the lubricant for the hot extrusion molding of the titanium alloy pipe as claimed in claim 2, wherein the temperature of the heating and melting in the first step is 1200-1400 ℃ and the time is 0.8-1.2 h.

4. The method for preparing the lubricant for the hot extrusion molding of the titanium alloy pipe as claimed in claim 2, wherein the drying temperature in the second step is 21-25 ℃ for 0.8-1.2 h, and the drying temperature in the second step is 50-70 ℃ for 0.8-1.2 h.

5. The method for preparing the lubricant for the hot extrusion molding of the titanium alloy pipe as claimed in claim 2, wherein the average particle size of the glass powder after sieving in the second step is 75 μm.

6. The use of the lubricant for hot-extrusion-molded titanium alloy pipes according to claim 1, as a lubricant for hot-extrusion-molded titanium alloy pipes.

7. The application of the lubricant for the hot extrusion forming of the titanium alloy pipe as claimed in claim 6, is characterized in that the specific process of the application is as follows: uniformly mixing the lubricant for the hot extrusion molding titanium alloy pipe with the organic binder and water, then coating the mixture on the outer surface of the titanium alloy pipe blank, and drying the titanium alloy pipe blank at room temperature to obtain the titanium alloy pipe blank with the coating.

8. The use of the lubricant for hot extrusion molding of titanium alloy pipes according to claim 6, wherein the organic binder is silicone acrylic resin.

9. The use of the lubricant for the hot-extrusion-molded titanium alloy pipe as claimed in claim 6, wherein the mass ratio of the lubricant to the organic binder for the hot-extrusion-molded titanium alloy pipe is 24: (33-40), wherein the mass ratio of the lubricant to water for the hot extrusion molding titanium alloy pipe is 24: (35-40).

10. The use of the lubricant for the hot extrusion forming of the titanium alloy pipe as claimed in claim 6, wherein the coating thickness is 0.1mm to 0.2mm, and the room temperature is 21 ℃ to 25 ℃.

Technical Field

The invention belongs to the field of lubricants and preparation thereof, and particularly relates to a lubricant for a hot extrusion molding titanium alloy pipe, and a preparation method and application thereof.

Background

Titanium and its alloys have poor flowability during extrusion due to their large friction coefficient, and therefore must be lubricated with a lubricant. Titanium is easy to form fusible eutectic with iron-based or nickel-based heat-resistant die steel materials of an extrusion needle, an extrusion die and an extrusion cylinder at 980 ℃ and 1030 ℃, and when the titanium alloy is subjected to hot extrusion, if no lubrication or poor lubrication is caused, not only is the die seriously worn, but also deep grooves, scratches and scratches are formed on the surface of an extruded product.

The lubrication problem is always a difficult point of the titanium alloy hot extrusion technology at home and abroad, and is also a research hotspot. In hot extrusion, a glass lubricant is the most potential lubricating material, however, the existing glass lubricant has the problems of poor fluidity, easy peeling and cracking and the like in the extrusion lubricating process. Therefore, there is a need to develop a lubricant having an excellent lubricating effect.

Disclosure of Invention

The invention provides a lubricant for hot extrusion molding titanium alloy pipes, a preparation method and application thereof, aiming at solving the technical problems of poor fluidity and easy peeling and cracking of the existing glass lubricant in the extrusion lubrication process.

The lubricant for the hot extrusion molding titanium alloy pipe comprises 35-45 parts by mass of SiO₂2-4 parts of Al₂O₃18 to 28 parts of B₂O₃17 to 21 parts of Na₂O, 5-8 parts of CaO, 1-5 parts of MgO, 1-8 parts of BaO, 1-5 parts of ZnO and 1-2 parts of LiO.

The preparation method of the lubricant for the hot extrusion molding titanium alloy pipe comprises the following steps:

firstly, SiO₂、Al₂O₃、B₂O₃、Na₂Mixing O, CaO, MgO, BaO, ZnO and LiO uniformly, and then heating and smelting to obtain molten glass;

and secondly, pouring the glass liquid into cold water, performing cold quenching to obtain glass particles, drying, adding absolute ethyl alcohol, performing ball milling to obtain glass powder, drying, and sieving to obtain the lubricant.

Further limiting, the heating and smelting in the step one are carried out at 1200-1400 ℃ for 0.8-1.2 h.

Further limiting, the drying temperature in the step two is 21-25 ℃, and the drying time is 0.8-1.2 h.

Further limiting, the drying temperature in the step two is 50-70 ℃, and the drying time is 0.8-1.2 h.

Further, the average particle size of the glass powder after sieving in the second step is 75 μm.

The invention discloses application of a lubricant for a hot extrusion molding titanium alloy pipe.

Further, the specific process of the application is as follows: uniformly mixing the lubricant for the hot extrusion molding titanium alloy pipe with the organic binder and water, then coating the mixture on the outer surface of the titanium alloy pipe blank, and drying the titanium alloy pipe blank at room temperature to obtain the titanium alloy pipe blank with the coating.

Further defined, the organic binder is a silicone acrylic resin.

Further limiting, the mass ratio of the lubricant to the organic binder for the hot extrusion forming titanium alloy pipe is 24: (33-40).

Further limiting, the mass ratio of the lubricant to water for the hot extrusion forming titanium alloy pipe is 24: (35-40).

Further defined, the coating thickness is 0.1mm to 0.2 mm.

Further defined, the room temperature is 21-25 ℃.

Compared with the prior art, the invention has the remarkable effects as follows:

1) the lubricant disclosed by the invention has the advantages that the non-uniform deformation degree caused by hot extrusion of the titanium alloy is reduced by strictly controlling the proportion of the materials, and the performances of high-temperature viscosity, high-temperature instant fusion, material property, heat conductivity coefficient, friction coefficient, substrate wettability and the like of the glass powder are improved.

2) The lubricant can form a molten protective film to be adhered to the surface of the titanium alloy to isolate oxygen during hot extrusion, so that the effects of lubrication, protection and heat preservation are achieved, the surface of the extruded TC4 titanium alloy pipe is integrally smooth without obvious longitudinal and transverse scratches and other defects after extrusion, and the integral surface quality is superior to that of the pipe extruded by the lubricant in the traditional process.

3) The lubricant disclosed by the invention is required to strictly control the coating thickness during coating, so that the bonding strength and the anti-oxidation effect are ensured, and the adverse phenomena of bubbling, cracking and the like on the surface of the coating are avoided.

Drawings

FIG. 1 is a DTA test chart of the lubricant obtained in example 2;

FIG. 2 is a graph showing the effect of coating in example 3;

FIG. 3 is a graph showing the distribution of microhardness in the depth direction of samples of example 3 and comparative example after heat preservation at 900 ℃ for 8 hours;

figure 4 is a photograph of the surface of the finished tube after testing-extrusion.

Detailed Description

Example 1: in the embodiment, the lubricant for the hot extrusion molding titanium alloy pipe comprises 36.5 parts by mass of SiO₂3 parts of Al₂O₃23 parts of B₂O₃19 parts of Na₂O, 6 parts of CaO, 3 parts of MgO, 5 parts of BaO, 3 parts of ZnO and 1.5 parts of LiO.

Example 2: the method for preparing the lubricant for the hot extrusion molding titanium alloy pipe material in the embodiment 1 comprises the following steps:

firstly, SiO₂、Al₂O₃、B₂O₃、Na₂Mixing O, CaO, MgO, BaO, ZnO and LiO uniformly, and then heating and smelting at 1300 ℃ for 1h to obtain molten glass;

and secondly, pouring the glass liquid into cold water, performing cold quenching to obtain glass particles, drying at 25 ℃ for 1h, adding absolute ethyl alcohol, performing ball milling to obtain glass powder with the particle size of 75 microns, drying at 60 ℃ for 1h, and sieving with a 200-mesh sieve to obtain the lubricant.

The lubricant prepared in example 2 was subjected to DTA testing with the following specific parameters: the temperature rise rate was 10 ℃/min and the atmosphere was air, to obtain the DTA test chart shown in FIG. 1. As can be seen from FIG. 1, an endothermic peak at about 580 ℃ is the softening temperature. Some weak exothermic peaks were observed in the temperature range of 620 ℃ to 750 ℃ probably due to devitrification. The endothermic peak at 800 ℃ shows that the glass powder starts to melt into viscous state, and can form a molten protective film to adhere to the surface of the titanium alloy to isolate oxygen, thereby playing roles of lubrication, protection and heat preservation.

Example 3: the application of the lubricant for the hot extrusion forming of the titanium alloy pipe in the embodiment 1 comprises the following specific steps:

24 parts of the lubricant for the hot extrusion molding titanium alloy pipe material of example 1, 38 parts of silicone acrylic resin and 38 parts of water were uniformly mixed, and then coated on a coating film having a size specification ofCoating the outer surface of the hollow titanium alloy tube blank with the thickness of 0.15mm, and drying at room temperature of 25 ℃ to obtain the hollow titanium alloy tube blankTo coated, size specification ofThe hollow titanium alloy tube blank of (2).

The effect diagram of the tube blank after complete drying in the embodiment is shown in fig. 2, and it can be seen from fig. 2 that the protective lubricating slurry is uniformly and densely coated on the surface of the titanium alloy after being dried, and has a certain bonding strength, and the surface of the coating has no undesirable phenomena such as bubbling and cracking.

Comparative example: the size specification of the uncoated lubricating coating in this example isHollow titanium alloy tube blank.

After the titanium alloy samples of the example 3 and the comparative example are subjected to high-temperature heat preservation at 900 ℃ for 8 hours, the protective performance of the coating is evaluated by testing the change of the microhardness of the sections of the coated and uncoated titanium alloy samples after the high-temperature heat preservation at 900 ℃ by adopting a digital microhardness tester with the model number of HXS-1000Z and the loading time of 10 s. The graph shown in fig. 3 is obtained, and it can be seen from fig. 3 that the surface hardness of the sample without the coating protection is significantly increased due to severe oxidation and outgassing, while the sample with the coating protection shows no significant difference between the internal and surface hardness. The microhardness curves of the two are compared, so that the coating plays a protection effect.

The effects of the present invention were confirmed by the following tests

Test one: example 3 the resulting coated, dimensional specification isThe hollow titanium alloy tube blank is put on a 1600T extruding machine to be extrudedWherein the lubricant of the extrusion cylinder is a mixture of engine oil, graphite and molybdenum disulfide, the lubricants of the extrusion needle and the extrusion die are mixtures of asphalt, graphite and molybdenum disulfide, the extrusion ratio is 3.6, the extrusion temperature is 980 ℃, and the die is preheated to 400 DEG CThe extrusion speed is 60 mm/s.

The outer surface condition of the TC4 titanium alloy pipe after the extrusion test is shown in FIG. 4, and it can be seen from FIG. 4 that the surface quality of different parts of the same pipe has little difference. The TC4 titanium alloy extruded tube has smooth surface, no obvious longitudinal and transverse scratches and other defects, and the integral surface quality is superior to that of the tube extruded by the traditional lubricant.